From 6f442e774b9236c999f36c2d7af17640f49bff99 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Tue, 9 Apr 2024 15:38:02 +0200
Subject: Adding upstream version 0.19.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 gitlint-core/LICENSE                               |  22 +
 gitlint-core/README.md                             |  26 +
 gitlint-core/gitlint/__init__.py                   |   8 +
 gitlint-core/gitlint/cache.py                      |  54 ++
 gitlint-core/gitlint/cli.py                        | 499 +++++++++++++
 gitlint-core/gitlint/config.py                     | 561 ++++++++++++++
 gitlint-core/gitlint/contrib/__init__.py           |   0
 gitlint-core/gitlint/contrib/rules/__init__.py     |   0
 .../gitlint/contrib/rules/authors_commit.py        |  45 ++
 .../gitlint/contrib/rules/conventional_commit.py   |  37 +
 .../contrib/rules/disallow_cleanup_commits.py      |  22 +
 gitlint-core/gitlint/contrib/rules/signedoff_by.py |  17 +
 gitlint-core/gitlint/deprecation.py                |  39 +
 gitlint-core/gitlint/display.py                    |  36 +
 gitlint-core/gitlint/exception.py                  |   2 +
 gitlint-core/gitlint/files/commit-msg              |  35 +
 gitlint-core/gitlint/files/gitlint                 | 140 ++++
 gitlint-core/gitlint/git.py                        | 510 +++++++++++++
 gitlint-core/gitlint/hooks.py                      |  65 ++
 gitlint-core/gitlint/lint.py                       | 123 +++
 gitlint-core/gitlint/options.py                    | 146 ++++
 gitlint-core/gitlint/rule_finder.py                | 155 ++++
 gitlint-core/gitlint/rules.py                      | 485 ++++++++++++
 gitlint-core/gitlint/shell.py                      |  78 ++
 gitlint-core/gitlint/tests/__init__.py             |   0
 gitlint-core/gitlint/tests/base.py                 | 227 ++++++
 gitlint-core/gitlint/tests/cli/test_cli.py         | 736 ++++++++++++++++++
 gitlint-core/gitlint/tests/cli/test_cli_hooks.py   | 277 +++++++
 gitlint-core/gitlint/tests/config/test_config.py   | 320 ++++++++
 .../gitlint/tests/config/test_config_builder.py    | 275 +++++++
 .../gitlint/tests/config/test_config_precedence.py |  98 +++
 .../gitlint/tests/config/test_rule_collection.py   |  62 ++
 gitlint-core/gitlint/tests/contrib/__init__.py     |   0
 .../gitlint/tests/contrib/rules/__init__.py        |   0
 .../tests/contrib/rules/test_authors_commit.py     | 105 +++
 .../contrib/rules/test_conventional_commit.py      |  82 ++
 .../contrib/rules/test_disallow_cleanup_commits.py |  34 +
 .../tests/contrib/rules/test_signedoff_by.py       |  28 +
 .../gitlint/tests/contrib/test_contrib_rules.py    |  69 ++
 .../tests/expected/cli/test_cli/test_contrib_1     |   2 +
 .../tests/expected/cli/test_cli/test_debug_1       | 139 ++++
 .../expected/cli/test_cli/test_input_stream_1      |   3 +
 .../cli/test_cli/test_input_stream_debug_1         |   3 +
 .../cli/test_cli/test_input_stream_debug_2         |  89 +++
 .../tests/expected/cli/test_cli/test_lint_commit_1 |   2 +
 .../cli/test_cli/test_lint_multiple_commits_1      |   8 +
 .../test_cli/test_lint_multiple_commits_config_1   |   6 +
 .../cli/test_cli/test_lint_multiple_commits_csv_1  |   8 +
 .../cli/test_cli/test_lint_staged_msg_filename_1   |   2 +
 .../cli/test_cli/test_lint_staged_msg_filename_2   |  93 +++
 .../expected/cli/test_cli/test_lint_staged_stdin_1 |   3 +
 .../expected/cli/test_cli/test_lint_staged_stdin_2 |  95 +++
 .../tests/expected/cli/test_cli/test_named_rules_1 |   4 +
 .../tests/expected/cli/test_cli/test_named_rules_2 |  92 +++
 .../cli/test_cli_hooks/test_hook_config_1_stderr   |   2 +
 .../cli/test_cli_hooks/test_hook_config_1_stdout   |   5 +
 .../cli/test_cli_hooks/test_hook_edit_1_stderr     |   6 +
 .../cli/test_cli_hooks/test_hook_edit_1_stdout     |  14 +
 .../test_cli_hooks/test_hook_local_commit_1_stderr |   2 +
 .../test_cli_hooks/test_hook_local_commit_1_stdout |   4 +
 .../cli/test_cli_hooks/test_hook_no_1_stderr       |   2 +
 .../cli/test_cli_hooks/test_hook_no_1_stdout       |   8 +
 .../cli/test_cli_hooks/test_hook_no_tty_1_stderr   |   2 +
 .../cli/test_cli_hooks/test_hook_no_tty_1_stdout   |   5 +
 .../test_hook_stdin_no_violations_1_stdout         |   2 +
 .../test_hook_stdin_violations_1_stderr            |   2 +
 .../test_hook_stdin_violations_1_stdout            |   5 +
 .../cli/test_cli_hooks/test_hook_yes_1_stderr      |   2 +
 .../cli/test_cli_hooks/test_hook_yes_1_stdout      |   4 +
 .../cli/test_cli_hooks/test_run_hook_negative_1    |   2 +
 .../cli/test_cli_hooks/test_run_hook_negative_2    |   2 +
 gitlint-core/gitlint/tests/git/test_git.py         | 121 +++
 gitlint-core/gitlint/tests/git/test_git_commit.py  | 825 +++++++++++++++++++++
 gitlint-core/gitlint/tests/git/test_git_context.py |  73 ++
 gitlint-core/gitlint/tests/rules/__init__.py       |   0
 .../gitlint/tests/rules/test_body_rules.py         | 235 ++++++
 .../tests/rules/test_configuration_rules.py        | 178 +++++
 .../gitlint/tests/rules/test_meta_rules.py         |  80 ++
 gitlint-core/gitlint/tests/rules/test_rules.py     |  32 +
 .../gitlint/tests/rules/test_title_rules.py        | 200 +++++
 .../gitlint/tests/rules/test_user_rules.py         | 266 +++++++
 .../gitlint/tests/samples/commit_message/fixup     |   1 +
 .../tests/samples/commit_message/fixup_amend       |   1 +
 .../gitlint/tests/samples/commit_message/merge     |   3 +
 .../tests/samples/commit_message/no-violations     |   6 +
 .../gitlint/tests/samples/commit_message/revert    |   3 +
 .../gitlint/tests/samples/commit_message/sample1   |  14 +
 .../gitlint/tests/samples/commit_message/sample2   |   1 +
 .../gitlint/tests/samples/commit_message/sample3   |   6 +
 .../gitlint/tests/samples/commit_message/sample4   |   7 +
 .../gitlint/tests/samples/commit_message/sample5   |   7 +
 .../gitlint/tests/samples/commit_message/squash    |   3 +
 gitlint-core/gitlint/tests/samples/config/AUTHORS  |   2 +
 .../gitlint/tests/samples/config/gitlintconfig     |  15 +
 .../tests/samples/config/invalid-option-value      |  11 +
 .../gitlint/tests/samples/config/named-rules       |   8 +
 .../gitlint/tests/samples/config/no-sections       |   1 +
 .../samples/config/nonexisting-general-option      |  13 +
 .../tests/samples/config/nonexisting-option        |  11 +
 .../gitlint/tests/samples/config/nonexisting-rule  |  11 +
 .../tests/samples/user_rules/bogus-file.txt        |   2 +
 .../user_rules/import_exception/invalid_python.py  |   2 +
 .../user_rules/incorrect_linerule/my_line_rule.py  |   8 +
 .../tests/samples/user_rules/my_commit_rules.foo   |  16 +
 .../tests/samples/user_rules/my_commit_rules.py    |  25 +
 .../samples/user_rules/parent_package/__init__.py  |  12 +
 .../user_rules/parent_package/my_commit_rules.py   |  10 +
 gitlint-core/gitlint/tests/test_cache.py           |  55 ++
 gitlint-core/gitlint/tests/test_deprecation.py     |  26 +
 gitlint-core/gitlint/tests/test_display.py         |  60 ++
 gitlint-core/gitlint/tests/test_hooks.py           | 139 ++++
 gitlint-core/gitlint/tests/test_lint.py            | 296 ++++++++
 gitlint-core/gitlint/tests/test_options.py         | 240 ++++++
 gitlint-core/gitlint/tests/test_utils.py           |  70 ++
 gitlint-core/gitlint/utils.py                      |  87 +++
 gitlint-core/pyproject.toml                        |  71 ++
 116 files changed, 9289 insertions(+)
 create mode 100644 gitlint-core/LICENSE
 create mode 100644 gitlint-core/README.md
 create mode 100644 gitlint-core/gitlint/__init__.py
 create mode 100644 gitlint-core/gitlint/cache.py
 create mode 100644 gitlint-core/gitlint/cli.py
 create mode 100644 gitlint-core/gitlint/config.py
 create mode 100644 gitlint-core/gitlint/contrib/__init__.py
 create mode 100644 gitlint-core/gitlint/contrib/rules/__init__.py
 create mode 100644 gitlint-core/gitlint/contrib/rules/authors_commit.py
 create mode 100644 gitlint-core/gitlint/contrib/rules/conventional_commit.py
 create mode 100644 gitlint-core/gitlint/contrib/rules/disallow_cleanup_commits.py
 create mode 100644 gitlint-core/gitlint/contrib/rules/signedoff_by.py
 create mode 100644 gitlint-core/gitlint/deprecation.py
 create mode 100644 gitlint-core/gitlint/display.py
 create mode 100644 gitlint-core/gitlint/exception.py
 create mode 100644 gitlint-core/gitlint/files/commit-msg
 create mode 100644 gitlint-core/gitlint/files/gitlint
 create mode 100644 gitlint-core/gitlint/git.py
 create mode 100644 gitlint-core/gitlint/hooks.py
 create mode 100644 gitlint-core/gitlint/lint.py
 create mode 100644 gitlint-core/gitlint/options.py
 create mode 100644 gitlint-core/gitlint/rule_finder.py
 create mode 100644 gitlint-core/gitlint/rules.py
 create mode 100644 gitlint-core/gitlint/shell.py
 create mode 100644 gitlint-core/gitlint/tests/__init__.py
 create mode 100644 gitlint-core/gitlint/tests/base.py
 create mode 100644 gitlint-core/gitlint/tests/cli/test_cli.py
 create mode 100644 gitlint-core/gitlint/tests/cli/test_cli_hooks.py
 create mode 100644 gitlint-core/gitlint/tests/config/test_config.py
 create mode 100644 gitlint-core/gitlint/tests/config/test_config_builder.py
 create mode 100644 gitlint-core/gitlint/tests/config/test_config_precedence.py
 create mode 100644 gitlint-core/gitlint/tests/config/test_rule_collection.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/__init__.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/rules/__init__.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/rules/test_conventional_commit.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/rules/test_disallow_cleanup_commits.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/rules/test_signedoff_by.py
 create mode 100644 gitlint-core/gitlint/tests/contrib/test_contrib_rules.py
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_contrib_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_debug_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_2
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_commit_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_config_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_csv_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_2
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_2
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_2
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_no_violations_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stderr
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stdout
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_1
 create mode 100644 gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_2
 create mode 100644 gitlint-core/gitlint/tests/git/test_git.py
 create mode 100644 gitlint-core/gitlint/tests/git/test_git_commit.py
 create mode 100644 gitlint-core/gitlint/tests/git/test_git_context.py
 create mode 100644 gitlint-core/gitlint/tests/rules/__init__.py
 create mode 100644 gitlint-core/gitlint/tests/rules/test_body_rules.py
 create mode 100644 gitlint-core/gitlint/tests/rules/test_configuration_rules.py
 create mode 100644 gitlint-core/gitlint/tests/rules/test_meta_rules.py
 create mode 100644 gitlint-core/gitlint/tests/rules/test_rules.py
 create mode 100644 gitlint-core/gitlint/tests/rules/test_title_rules.py
 create mode 100644 gitlint-core/gitlint/tests/rules/test_user_rules.py
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/fixup
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/fixup_amend
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/merge
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/no-violations
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/revert
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/sample1
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/sample2
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/sample3
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/sample4
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/sample5
 create mode 100644 gitlint-core/gitlint/tests/samples/commit_message/squash
 create mode 100644 gitlint-core/gitlint/tests/samples/config/AUTHORS
 create mode 100644 gitlint-core/gitlint/tests/samples/config/gitlintconfig
 create mode 100644 gitlint-core/gitlint/tests/samples/config/invalid-option-value
 create mode 100644 gitlint-core/gitlint/tests/samples/config/named-rules
 create mode 100644 gitlint-core/gitlint/tests/samples/config/no-sections
 create mode 100644 gitlint-core/gitlint/tests/samples/config/nonexisting-general-option
 create mode 100644 gitlint-core/gitlint/tests/samples/config/nonexisting-option
 create mode 100644 gitlint-core/gitlint/tests/samples/config/nonexisting-rule
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/bogus-file.txt
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/import_exception/invalid_python.py
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/incorrect_linerule/my_line_rule.py
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.foo
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.py
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/parent_package/__init__.py
 create mode 100644 gitlint-core/gitlint/tests/samples/user_rules/parent_package/my_commit_rules.py
 create mode 100644 gitlint-core/gitlint/tests/test_cache.py
 create mode 100644 gitlint-core/gitlint/tests/test_deprecation.py
 create mode 100644 gitlint-core/gitlint/tests/test_display.py
 create mode 100644 gitlint-core/gitlint/tests/test_hooks.py
 create mode 100644 gitlint-core/gitlint/tests/test_lint.py
 create mode 100644 gitlint-core/gitlint/tests/test_options.py
 create mode 100644 gitlint-core/gitlint/tests/test_utils.py
 create mode 100644 gitlint-core/gitlint/utils.py
 create mode 100644 gitlint-core/pyproject.toml

(limited to 'gitlint-core')

diff --git a/gitlint-core/LICENSE b/gitlint-core/LICENSE
new file mode 100644
index 0000000..122bd28
--- /dev/null
+++ b/gitlint-core/LICENSE
@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Joris Roovers
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
diff --git a/gitlint-core/README.md b/gitlint-core/README.md
new file mode 100644
index 0000000..dfbbe7f
--- /dev/null
+++ b/gitlint-core/README.md
@@ -0,0 +1,26 @@
+# Gitlint-core
+
+# gitlint: [jorisroovers.github.io/gitlint](http://jorisroovers.github.io/gitlint/) #
+
+[![Tests](https://github.com/jorisroovers/gitlint/workflows/Tests%20and%20Checks/badge.svg)](https://github.com/jorisroovers/gitlint/actions?query=workflow%3A%22Tests+and+Checks%22)
+[![Coverage Status](https://coveralls.io/repos/github/jorisroovers/gitlint/badge.svg?branch=fix-coveralls)](https://coveralls.io/github/jorisroovers/gitlint?branch=fix-coveralls)
+[![PyPi Package](https://img.shields.io/pypi/v/gitlint.png)](https://pypi.python.org/pypi/gitlint)
+![Supported Python Versions](https://img.shields.io/pypi/pyversions/gitlint.svg)
+
+Git commit message linter written in python, checks your commit messages for style.
+
+**See [jorisroovers.github.io/gitlint](http://jorisroovers.github.io/gitlint/) for full documentation.**
+
+<a href="http://jorisroovers.github.io/gitlint/" target="_blank">
+<img src="https://raw.githubusercontent.com/jorisroovers/gitlint/main/docs/images/readme-gitlint.png" />
+</a>
+
+## Contributing ##
+All contributions are welcome and very much appreciated!
+
+**I'm [looking for contributors](https://github.com/jorisroovers/gitlint/issues/134) that are interested in taking a more active co-maintainer role as it's becoming increasingly difficult for me to find time to maintain gitlint. Please leave a comment in [#134](https://github.com/jorisroovers/gitlint/issues/134) if you're interested!**
+
+See [jorisroovers.github.io/gitlint/contributing](http://jorisroovers.github.io/gitlint/contributing) for details on
+how to get started - it's easy!
+
+We maintain a [loose project plan on Github Projects](https://github.com/users/jorisroovers/projects/1/views/1).
diff --git a/gitlint-core/gitlint/__init__.py b/gitlint-core/gitlint/__init__.py
new file mode 100644
index 0000000..a2339fd
--- /dev/null
+++ b/gitlint-core/gitlint/__init__.py
@@ -0,0 +1,8 @@
+import sys
+
+if sys.version_info >= (3, 8):
+    from importlib import metadata  # pragma: nocover
+else:
+    import importlib_metadata as metadata  # pragma: nocover
+
+__version__ = metadata.version("gitlint-core")
diff --git a/gitlint-core/gitlint/cache.py b/gitlint-core/gitlint/cache.py
new file mode 100644
index 0000000..a3dd0c8
--- /dev/null
+++ b/gitlint-core/gitlint/cache.py
@@ -0,0 +1,54 @@
+class PropertyCache:
+    """Mixin class providing a simple cache."""
+
+    def __init__(self):
+        self._cache = {}
+
+    def _try_cache(self, cache_key, cache_populate_func):
+        """Tries to get a value from the cache identified by `cache_key`.
+        If no value is found in the cache, do a function call to `cache_populate_func` to populate the cache
+        and then return the value from the cache."""
+        if cache_key not in self._cache:
+            cache_populate_func()
+        return self._cache[cache_key]
+
+
+def cache(original_func=None, cachekey=None):
+    """Cache decorator. Caches function return values.
+    Requires the parent class to extend and initialize PropertyCache.
+    Usage:
+        # Use function name as cache key
+        @cache
+        def myfunc(args):
+            ...
+
+        # Specify cache key
+        @cache(cachekey="foobar")
+        def myfunc(args):
+            ...
+    """
+
+    # Decorators with optional arguments are a bit convoluted in python, see some of the links below for details.
+
+    def cache_decorator(func):
+        # Use 'nonlocal' keyword to access parent function variable:
+        # https://stackoverflow.com/a/14678445/381010
+        nonlocal cachekey
+        if not cachekey:
+            cachekey = func.__name__
+
+        def wrapped(*args):
+            def cache_func_result():
+                # Call decorated function and store its result in the cache
+                args[0]._cache[cachekey] = func(*args)
+
+            return args[0]._try_cache(cachekey, cache_func_result)
+
+        return wrapped
+
+    # To support optional kwargs for decorators, we need to check if a function is passed as first argument or not.
+    # https://stackoverflow.com/a/24617244/381010
+    if original_func:
+        return cache_decorator(original_func)
+
+    return cache_decorator
diff --git a/gitlint-core/gitlint/cli.py b/gitlint-core/gitlint/cli.py
new file mode 100644
index 0000000..619f006
--- /dev/null
+++ b/gitlint-core/gitlint/cli.py
@@ -0,0 +1,499 @@
+import copy
+import logging
+import os
+import platform
+import stat
+import sys
+
+import click
+
+import gitlint
+from gitlint import hooks
+from gitlint.config import LintConfigBuilder, LintConfigError, LintConfigGenerator
+from gitlint.deprecation import DEPRECATED_LOG_FORMAT
+from gitlint.deprecation import LOG as DEPRECATED_LOG
+from gitlint.exception import GitlintError
+from gitlint.git import GitContext, GitContextError, git_version
+from gitlint.lint import GitLinter
+from gitlint.shell import shell
+from gitlint.utils import LOG_FORMAT
+
+# Error codes
+GITLINT_SUCCESS = 0
+MAX_VIOLATION_ERROR_CODE = 252
+USAGE_ERROR_CODE = 253
+GIT_CONTEXT_ERROR_CODE = 254
+CONFIG_ERROR_CODE = 255
+
+DEFAULT_CONFIG_FILE = ".gitlint"
+# -n: disable swap files. This fixes a vim error on windows (E303: Unable to open swap file for <path>)
+DEFAULT_COMMIT_MSG_EDITOR = "vim -n"
+
+# Since we use the return code to denote the amount of errors, we need to change the default click usage error code
+click.UsageError.exit_code = USAGE_ERROR_CODE
+
+# We don't use logging.getLogger(__main__) here because that will cause DEBUG output to be lost
+# when invoking gitlint as a python module (python -m gitlint.cli)
+LOG = logging.getLogger("gitlint.cli")
+
+
+class GitLintUsageError(GitlintError):
+    """Exception indicating there is an issue with how gitlint is used."""
+
+
+def setup_logging():
+    """Setup gitlint logging"""
+
+    # Root log, mostly used for debug
+    root_log = logging.getLogger("gitlint")
+    root_log.propagate = False  # Don't propagate to child loggers, the gitlint root logger handles everything
+    root_log.setLevel(logging.WARN)
+    handler = logging.StreamHandler()
+    formatter = logging.Formatter(LOG_FORMAT)
+    handler.setFormatter(formatter)
+    root_log.addHandler(handler)
+
+    # Deprecated log, to log deprecation warnings
+    DEPRECATED_LOG.propagate = False  # Don't propagate to child logger
+    DEPRECATED_LOG.setLevel(logging.WARNING)
+    deprecated_log_handler = logging.StreamHandler()
+    deprecated_log_handler.setFormatter(logging.Formatter(DEPRECATED_LOG_FORMAT))
+    DEPRECATED_LOG.addHandler(deprecated_log_handler)
+
+
+def log_system_info():
+    LOG.debug("Platform: %s", platform.platform())
+    LOG.debug("Python version: %s", sys.version)
+    LOG.debug("Git version: %s", git_version())
+    LOG.debug("Gitlint version: %s", gitlint.__version__)
+    LOG.debug("GITLINT_USE_SH_LIB: %s", os.environ.get("GITLINT_USE_SH_LIB", "[NOT SET]"))
+    LOG.debug("TERMINAL_ENCODING: %s", gitlint.utils.TERMINAL_ENCODING)
+    LOG.debug("FILE_ENCODING: %s", gitlint.utils.FILE_ENCODING)
+
+
+def build_config(
+    target,
+    config_path,
+    c,
+    extra_path,
+    ignore,
+    contrib,
+    ignore_stdin,
+    staged,
+    fail_without_commits,
+    verbose,
+    silent,
+    debug,
+):
+    """Creates a LintConfig object based on a set of commandline parameters."""
+    config_builder = LintConfigBuilder()
+    # Config precedence:
+    # First, load default config or config from configfile
+    if config_path:
+        config_builder.set_from_config_file(config_path)
+    elif os.path.exists(DEFAULT_CONFIG_FILE):
+        config_builder.set_from_config_file(DEFAULT_CONFIG_FILE)
+
+    # Then process any commandline configuration flags
+    config_builder.set_config_from_string_list(c)
+
+    # Finally, overwrite with any convenience commandline flags
+    if ignore:
+        config_builder.set_option("general", "ignore", ignore)
+
+    if contrib:
+        config_builder.set_option("general", "contrib", contrib)
+
+    if ignore_stdin:
+        config_builder.set_option("general", "ignore-stdin", ignore_stdin)
+
+    if silent:
+        config_builder.set_option("general", "verbosity", 0)
+    elif verbose > 0:
+        config_builder.set_option("general", "verbosity", verbose)
+
+    if extra_path:
+        config_builder.set_option("general", "extra-path", extra_path)
+
+    if target:
+        config_builder.set_option("general", "target", target)
+
+    if debug:
+        config_builder.set_option("general", "debug", debug)
+
+    if staged:
+        config_builder.set_option("general", "staged", staged)
+
+    if fail_without_commits:
+        config_builder.set_option("general", "fail-without-commits", fail_without_commits)
+
+    config = config_builder.build()
+
+    return config, config_builder
+
+
+def get_stdin_data():
+    """Helper function that returns data sent to stdin or False if nothing is sent"""
+    # STDIN can only be 3 different types of things ("modes")
+    #  1. An interactive terminal device (i.e. a TTY -> sys.stdin.isatty() or stat.S_ISCHR)
+    #  2. A (named) pipe (stat.S_ISFIFO)
+    #  3. A regular file (stat.S_ISREG)
+    # Technically, STDIN can also be other device type like a named unix socket (stat.S_ISSOCK), but we don't
+    # support that in gitlint (at least not today).
+    #
+    # Now, the behavior that we want is the following:
+    # If someone sends something directly to gitlint via a pipe or a regular file, read it. If not, read from the
+    # local repository.
+    # Note that we don't care about whether STDIN is a TTY or not, we only care whether data is via a pipe or regular
+    # file.
+    # However, in case STDIN is not a TTY, it HAS to be one of the 2 other things (pipe or regular file), even if
+    # no-one is actually sending anything to gitlint over them. In this case, we still want to read from the local
+    # repository.
+    # To support this use-case (which is common in CI runners such as Jenkins and Gitlab), we need to actually attempt
+    # to read from STDIN in case it's a pipe or regular file. In case that fails, then we'll fall back to reading
+    # from the local repo.
+
+    mode = os.fstat(sys.stdin.fileno()).st_mode
+    stdin_is_pipe_or_file = stat.S_ISFIFO(mode) or stat.S_ISREG(mode)
+    if stdin_is_pipe_or_file:
+        input_data = sys.stdin.read()
+        # Only return the input data if there's actually something passed
+        # i.e. don't consider empty piped data
+        if input_data:
+            return str(input_data)
+    return False
+
+
+def build_git_context(lint_config, msg_filename, commit_hash, refspec):
+    """Builds a git context based on passed parameters and order of precedence"""
+
+    # Determine which GitContext method to use if a custom message is passed
+    from_commit_msg = GitContext.from_commit_msg
+    if lint_config.staged:
+        LOG.debug("Fetching additional meta-data from staged commit")
+
+        def from_commit_msg(message):
+            return GitContext.from_staged_commit(message, lint_config.target)
+
+    # Order of precedence:
+    # 1. Any data specified via --msg-filename
+    if msg_filename:
+        LOG.debug("Using --msg-filename.")
+        return from_commit_msg(str(msg_filename.read()))
+
+    # 2. Any data sent to stdin (unless stdin is being ignored)
+    if not lint_config.ignore_stdin:
+        stdin_input = get_stdin_data()
+        if stdin_input:
+            LOG.debug("Stdin data: '%s'", stdin_input)
+            LOG.debug("Stdin detected and not ignored. Using as input.")
+            return from_commit_msg(stdin_input)
+
+    if lint_config.staged:
+        raise GitLintUsageError(
+            "The 'staged' option (--staged) can only be used when using '--msg-filename' or "
+            "when piping data to gitlint via stdin."
+        )
+
+    # 3. Fallback to reading from local repository
+    LOG.debug("No --msg-filename flag, no or empty data passed to stdin. Using the local repo.")
+
+    if commit_hash and refspec:
+        raise GitLintUsageError("--commit and --commits are mutually exclusive, use one or the other.")
+
+    # 3.1 Linting a range of commits
+    if refspec:
+        # 3.1.1 Not real refspec, but comma-separated list of commit hashes
+        if "," in refspec:
+            commit_hashes = [hash.strip() for hash in refspec.split(",") if hash]
+            return GitContext.from_local_repository(lint_config.target, commit_hashes=commit_hashes)
+        # 3.1.2 Real refspec
+        return GitContext.from_local_repository(lint_config.target, refspec=refspec)
+
+    # 3.2 Linting a specific commit
+    if commit_hash:
+        return GitContext.from_local_repository(lint_config.target, commit_hashes=[commit_hash])
+
+    # 3.3 Fallback to linting the current HEAD
+    return GitContext.from_local_repository(lint_config.target)
+
+
+def handle_gitlint_error(ctx, exc):
+    """Helper function to handle exceptions"""
+    if isinstance(exc, GitContextError):
+        click.echo(exc)
+        ctx.exit(GIT_CONTEXT_ERROR_CODE)
+    elif isinstance(exc, GitLintUsageError):
+        click.echo(f"Error: {exc}")
+        ctx.exit(USAGE_ERROR_CODE)
+    elif isinstance(exc, LintConfigError):
+        click.echo(f"Config Error: {exc}")
+        ctx.exit(CONFIG_ERROR_CODE)
+
+
+class ContextObj:
+    """Simple class to hold data that is passed between Click commands via the Click context."""
+
+    def __init__(self, config, config_builder, commit_hash, refspec, msg_filename, gitcontext=None):
+        self.config = config
+        self.config_builder = config_builder
+        self.commit_hash = commit_hash
+        self.refspec = refspec
+        self.msg_filename = msg_filename
+        self.gitcontext = gitcontext
+
+
+# fmt: off
+@click.group(invoke_without_command=True, context_settings={"max_content_width": 120},
+             epilog="When no COMMAND is specified, gitlint defaults to 'gitlint lint'.")
+@click.option("--target", envvar="GITLINT_TARGET",
+              type=click.Path(exists=True, resolve_path=True, file_okay=False, readable=True),
+              help="Path of the target git repository. [default: current working directory]")
+@click.option("-C", "--config", envvar="GITLINT_CONFIG",
+              type=click.Path(exists=True, dir_okay=False, readable=True, resolve_path=True),
+              help=f"Config file location [default: {DEFAULT_CONFIG_FILE}]")
+@click.option("-c", multiple=True,
+              help="Config flags in format <rule>.<option>=<value> (e.g.: -c T1.line-length=80). " +
+                   "Flag can be used multiple times to set multiple config values.")
+@click.option("--commit", envvar="GITLINT_COMMIT", default=None, help="Hash (SHA) of specific commit to lint.")
+@click.option("--commits", envvar="GITLINT_COMMITS", default=None,
+              help="The range of commits (refspec or comma-separated hashes) to lint. [default: HEAD]")
+@click.option("-e", "--extra-path", envvar="GITLINT_EXTRA_PATH",
+              help="Path to a directory or python module with extra user-defined rules",
+              type=click.Path(exists=True, resolve_path=True, readable=True))
+@click.option("--ignore", envvar="GITLINT_IGNORE", default="", help="Ignore rules (comma-separated by id or name).")
+@click.option("--contrib", envvar="GITLINT_CONTRIB", default="",
+              help="Contrib rules to enable (comma-separated by id or name).")
+@click.option("--msg-filename", type=click.File(encoding=gitlint.utils.FILE_ENCODING),
+              help="Path to a file containing a commit-msg.")
+@click.option("--ignore-stdin", envvar="GITLINT_IGNORE_STDIN", is_flag=True,
+              help="Ignore any stdin data. Useful for running in CI server.")
+@click.option("--staged", envvar="GITLINT_STAGED", is_flag=True,
+              help="Attempt smart guesses about meta info (like author name, email, branch, changed files, etc) " +
+                   "for staged commits.")
+@click.option("--fail-without-commits", envvar="GITLINT_FAIL_WITHOUT_COMMITS", is_flag=True,
+              help="Hard fail when the target commit range is empty.")
+@click.option("-v", "--verbose", envvar="GITLINT_VERBOSITY", count=True, default=0,
+              help="Verbosity, use multiple times for more verbose output (e.g.: -v, -vv, -vvv). [default: -vvv]", )
+@click.option("-s", "--silent", envvar="GITLINT_SILENT", is_flag=True,
+              help="Silent mode (no output). Takes precedence over -v, -vv, -vvv.")
+@click.option("-d", "--debug", envvar="GITLINT_DEBUG", help="Enable debugging output.", is_flag=True)
+@click.version_option(version=gitlint.__version__)
+@click.pass_context
+def cli(
+        ctx, target, config, c, commit, commits, extra_path, ignore, contrib,
+        msg_filename, ignore_stdin, staged, fail_without_commits, verbose,
+        silent, debug,
+):
+    """ Git lint tool, checks your git commit messages for styling issues
+
+        Documentation: http://jorisroovers.github.io/gitlint
+    """
+    try:
+        if debug:
+            logging.getLogger("gitlint").setLevel(logging.DEBUG)
+            DEPRECATED_LOG.setLevel(logging.DEBUG)
+        LOG.debug("To report issues, please visit https://github.com/jorisroovers/gitlint/issues")
+
+        log_system_info()
+
+        # Get the lint config from the commandline parameters and
+        # store it in the context (click allows storing an arbitrary object in ctx.obj).
+        config, config_builder = build_config(target, config, c, extra_path, ignore, contrib, ignore_stdin,
+                                              staged, fail_without_commits, verbose, silent, debug)
+        LOG.debug("Configuration\n%s", config)
+
+        ctx.obj = ContextObj(config, config_builder, commit, commits, msg_filename)
+
+        # If no subcommand is specified, then just lint
+        if ctx.invoked_subcommand is None:
+            ctx.invoke(lint)
+
+    except GitlintError as e:
+        handle_gitlint_error(ctx, e)
+# fmt: on
+
+
+@cli.command("lint")
+@click.pass_context
+def lint(ctx):
+    """Lints a git repository [default command]"""
+    lint_config = ctx.obj.config
+    refspec = ctx.obj.refspec
+    commit_hash = ctx.obj.commit_hash
+    msg_filename = ctx.obj.msg_filename
+
+    gitcontext = build_git_context(lint_config, msg_filename, commit_hash, refspec)
+    # Set gitcontext in the click context, so we can use it in command that are ran after this
+    # in particular, this is used by run-hook
+    ctx.obj.gitcontext = gitcontext
+
+    number_of_commits = len(gitcontext.commits)
+    # Exit if we don't have commits in the specified range. Use a 0 exit code, since a popular use-case is one
+    # where users are using --commits in a check job to check the commit messages inside a CI job. By returning 0, we
+    # ensure that these jobs don't fail if for whatever reason the specified commit range is empty.
+    # This behavior can be overridden by using the --fail-without-commits flag.
+    if number_of_commits == 0:
+        LOG.debug('No commits in range "%s"', refspec)
+        if lint_config.fail_without_commits:
+            raise GitLintUsageError(f'No commits in range "{refspec}"')
+        ctx.exit(GITLINT_SUCCESS)
+
+    LOG.debug("Linting %d commit(s)", number_of_commits)
+    general_config_builder = ctx.obj.config_builder
+    last_commit = gitcontext.commits[-1]
+
+    # Let's get linting!
+    first_violation = True
+    exit_code = GITLINT_SUCCESS
+    for commit in gitcontext.commits:
+        # Build a config_builder taking into account the commit specific config (if any)
+        config_builder = general_config_builder.clone()
+        config_builder.set_config_from_commit(commit)
+
+        # Create a deepcopy from the original config, so we have a unique config object per commit
+        # This is important for configuration rules to be able to modifying the config on a per commit basis
+        commit_config = config_builder.build(copy.deepcopy(lint_config))
+
+        # Actually do the linting
+        linter = GitLinter(commit_config)
+        violations = linter.lint(commit)
+        # exit code equals the total number of violations in all commits
+        exit_code += len(violations)
+        if violations:
+            # Display the commit hash & new lines intelligently
+            if number_of_commits > 1 and commit.sha:
+                commit_separator = "\n" if not first_violation or commit is last_commit else ""
+                linter.display.e(f"{commit_separator}Commit {commit.sha[:10]}:")
+            linter.print_violations(violations)
+            first_violation = False
+
+    # cap actual max exit code because bash doesn't like exit codes larger than 255:
+    # http://tldp.org/LDP/abs/html/exitcodes.html
+    exit_code = min(MAX_VIOLATION_ERROR_CODE, exit_code)
+    LOG.debug("Exit Code = %s", exit_code)
+    ctx.exit(exit_code)
+
+
+@cli.command("install-hook")
+@click.pass_context
+def install_hook(ctx):
+    """Install gitlint as a git commit-msg hook."""
+    try:
+        hooks.GitHookInstaller.install_commit_msg_hook(ctx.obj.config)
+        hook_path = hooks.GitHookInstaller.commit_msg_hook_path(ctx.obj.config)
+        click.echo(f"Successfully installed gitlint commit-msg hook in {hook_path}")
+        ctx.exit(GITLINT_SUCCESS)
+    except hooks.GitHookInstallerError as e:
+        click.echo(e, err=True)
+        ctx.exit(GIT_CONTEXT_ERROR_CODE)
+
+
+@cli.command("uninstall-hook")
+@click.pass_context
+def uninstall_hook(ctx):
+    """Uninstall gitlint commit-msg hook."""
+    try:
+        hooks.GitHookInstaller.uninstall_commit_msg_hook(ctx.obj.config)
+        hook_path = hooks.GitHookInstaller.commit_msg_hook_path(ctx.obj.config)
+        click.echo(f"Successfully uninstalled gitlint commit-msg hook from {hook_path}")
+        ctx.exit(GITLINT_SUCCESS)
+    except hooks.GitHookInstallerError as e:
+        click.echo(e, err=True)
+        ctx.exit(GIT_CONTEXT_ERROR_CODE)
+
+
+@cli.command("run-hook")
+@click.pass_context
+def run_hook(ctx):
+    """Runs the gitlint commit-msg hook."""
+
+    exit_code = 1
+    while exit_code > 0:
+        try:
+            click.echo("gitlint: checking commit message...")
+            ctx.invoke(lint)
+        except GitlintError as e:
+            handle_gitlint_error(ctx, e)
+        except click.exceptions.Exit as e:
+            # Flush stderr andstdout, this resolves an issue with output ordering in Cygwin
+            sys.stderr.flush()
+            sys.stdout.flush()
+
+            exit_code = e.exit_code
+            if exit_code == GITLINT_SUCCESS:
+                click.echo("gitlint: " + click.style("OK", fg="green") + " (no violations in commit message)")
+                continue
+
+            click.echo("-----------------------------------------------")
+            click.echo("gitlint: " + click.style("Your commit message contains violations.", fg="red"))
+
+            value = None
+            while value not in ["y", "n", "e"]:
+                click.echo(
+                    "Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] ",
+                    nl=False,
+                )
+
+                # Ideally, we'd want to use click.getchar() or click.prompt() to get user's input here instead of
+                # input(). However, those functions currently don't support getting answers from stdin.
+                # This wouldn't be a huge issue since this is unlikely to occur in the real world,
+                # were it not that we use a stdin to pipe answers into gitlint in our integration tests.
+                # If that ever changes, we can revisit this.
+                # Related click pointers:
+                # - https://github.com/pallets/click/issues/1370
+                # - https://github.com/pallets/click/pull/1372
+                # - From https://click.palletsprojects.com/en/7.x/utils/#getting-characters-from-terminal
+                #   Note that this function will always read from the terminal, even if stdin is instead a pipe.
+                value = input()
+
+            if value == "y":
+                LOG.debug("run-hook: commit message accepted")
+                exit_code = GITLINT_SUCCESS
+            elif value == "e":
+                LOG.debug("run-hook: editing commit message")
+                msg_filename = ctx.obj.msg_filename
+                if msg_filename:
+                    msg_filename.seek(0)
+                    editor = os.environ.get("EDITOR", DEFAULT_COMMIT_MSG_EDITOR)
+                    msg_filename_path = os.path.realpath(msg_filename.name)
+                    LOG.debug("run-hook: %s %s", editor, msg_filename_path)
+                    shell(editor + " " + msg_filename_path)
+                else:
+                    click.echo("Editing only possible when --msg-filename is specified.")
+                    ctx.exit(exit_code)
+            elif value == "n":
+                LOG.debug("run-hook: commit message declined")
+                click.echo("Commit aborted.")
+                click.echo("Your commit message: ")
+                click.echo("-----------------------------------------------")
+                click.echo(ctx.obj.gitcontext.commits[0].message.full)
+                click.echo("-----------------------------------------------")
+                ctx.exit(exit_code)
+
+    ctx.exit(exit_code)
+
+
+@cli.command("generate-config")
+@click.pass_context
+def generate_config(ctx):
+    """Generates a sample gitlint config file."""
+    path = click.prompt("Please specify a location for the sample gitlint config file", default=DEFAULT_CONFIG_FILE)
+    path = os.path.realpath(path)
+    dir_name = os.path.dirname(path)
+    if not os.path.exists(dir_name):
+        click.echo(f"Error: Directory '{dir_name}' does not exist.", err=True)
+        ctx.exit(USAGE_ERROR_CODE)
+    elif os.path.exists(path):
+        click.echo(f'Error: File "{path}" already exists.', err=True)
+        ctx.exit(USAGE_ERROR_CODE)
+
+    LintConfigGenerator.generate_config(path)
+    click.echo(f"Successfully generated {path}")
+    ctx.exit(GITLINT_SUCCESS)
+
+
+# Let's Party!
+setup_logging()
+if __name__ == "__main__":
+    cli()  # pragma: no cover
diff --git a/gitlint-core/gitlint/config.py b/gitlint-core/gitlint/config.py
new file mode 100644
index 0000000..4b38d90
--- /dev/null
+++ b/gitlint-core/gitlint/config.py
@@ -0,0 +1,561 @@
+import copy
+import os
+import re
+import shutil
+from collections import OrderedDict
+from configparser import ConfigParser
+from configparser import Error as ConfigParserError
+
+from gitlint import (
+    options,
+    rule_finder,
+    rules,
+)
+from gitlint.contrib import rules as contrib_rules
+from gitlint.exception import GitlintError
+from gitlint.utils import FILE_ENCODING
+
+
+def handle_option_error(func):
+    """Decorator that calls given method/function and handles any RuleOptionError gracefully by converting it to a
+    LintConfigError."""
+
+    def wrapped(*args):
+        try:
+            return func(*args)
+        except options.RuleOptionError as e:
+            raise LintConfigError(str(e)) from e
+
+    return wrapped
+
+
+class LintConfigError(GitlintError):
+    pass
+
+
+class LintConfig:
+    """Class representing gitlint configuration.
+    Contains active config as well as number of methods to easily get/set the config.
+    """
+
+    # Default tuple of rule classes (tuple because immutable).
+    default_rule_classes = (
+        rules.IgnoreByTitle,
+        rules.IgnoreByBody,
+        rules.IgnoreBodyLines,
+        rules.IgnoreByAuthorName,
+        rules.TitleMaxLength,
+        rules.TitleTrailingWhitespace,
+        rules.TitleLeadingWhitespace,
+        rules.TitleTrailingPunctuation,
+        rules.TitleHardTab,
+        rules.TitleMustNotContainWord,
+        rules.TitleRegexMatches,
+        rules.TitleMinLength,
+        rules.BodyMaxLineLength,
+        rules.BodyMinLength,
+        rules.BodyMissing,
+        rules.BodyTrailingWhitespace,
+        rules.BodyHardTab,
+        rules.BodyFirstLineEmpty,
+        rules.BodyChangedFileMention,
+        rules.BodyRegexMatches,
+        rules.AuthorValidEmail,
+    )
+
+    def __init__(self):
+        self.rules = RuleCollection(self.default_rule_classes)
+        self._verbosity = options.IntOption("verbosity", 3, "Verbosity")
+        self._ignore_merge_commits = options.BoolOption("ignore-merge-commits", True, "Ignore merge commits")
+        self._ignore_fixup_commits = options.BoolOption("ignore-fixup-commits", True, "Ignore fixup commits")
+        self._ignore_fixup_amend_commits = options.BoolOption(
+            "ignore-fixup-amend-commits", True, "Ignore fixup amend commits"
+        )
+        self._ignore_squash_commits = options.BoolOption("ignore-squash-commits", True, "Ignore squash commits")
+        self._ignore_revert_commits = options.BoolOption("ignore-revert-commits", True, "Ignore revert commits")
+        self._debug = options.BoolOption("debug", False, "Enable debug mode")
+        self._extra_path = None
+        target_description = "Path of the target git repository (default=current working directory)"
+        self._target = options.PathOption("target", os.path.realpath(os.getcwd()), target_description)
+        self._ignore = options.ListOption("ignore", [], "List of rule-ids to ignore")
+        self._contrib = options.ListOption("contrib", [], "List of contrib-rules to enable")
+        self._config_path = None
+        ignore_stdin_description = "Ignore any stdin data. Useful for running in CI server."
+        self._ignore_stdin = options.BoolOption("ignore-stdin", False, ignore_stdin_description)
+        self._staged = options.BoolOption("staged", False, "Read staged commit meta-info from the local repository.")
+        self._fail_without_commits = options.BoolOption(
+            "fail-without-commits", False, "Hard fail when the target commit range is empty"
+        )
+        self._regex_style_search = options.BoolOption(
+            "regex-style-search", False, "Use `search` instead of `match` semantics for regex rules"
+        )
+
+    @property
+    def target(self):
+        return self._target.value if self._target else None
+
+    @target.setter
+    @handle_option_error
+    def target(self, value):
+        return self._target.set(value)
+
+    @property
+    def verbosity(self):
+        return self._verbosity.value
+
+    @verbosity.setter
+    @handle_option_error
+    def verbosity(self, value):
+        self._verbosity.set(value)
+        if self.verbosity < 0 or self.verbosity > 3:  # noqa: PLR2004 (Magic value used in comparison)
+            raise LintConfigError("Option 'verbosity' must be set between 0 and 3")
+
+    @property
+    def ignore_merge_commits(self):
+        return self._ignore_merge_commits.value
+
+    @ignore_merge_commits.setter
+    @handle_option_error
+    def ignore_merge_commits(self, value):
+        return self._ignore_merge_commits.set(value)
+
+    @property
+    def ignore_fixup_commits(self):
+        return self._ignore_fixup_commits.value
+
+    @ignore_fixup_commits.setter
+    @handle_option_error
+    def ignore_fixup_commits(self, value):
+        return self._ignore_fixup_commits.set(value)
+
+    @property
+    def ignore_fixup_amend_commits(self):
+        return self._ignore_fixup_amend_commits.value
+
+    @ignore_fixup_amend_commits.setter
+    @handle_option_error
+    def ignore_fixup_amend_commits(self, value):
+        return self._ignore_fixup_amend_commits.set(value)
+
+    @property
+    def ignore_squash_commits(self):
+        return self._ignore_squash_commits.value
+
+    @ignore_squash_commits.setter
+    @handle_option_error
+    def ignore_squash_commits(self, value):
+        return self._ignore_squash_commits.set(value)
+
+    @property
+    def ignore_revert_commits(self):
+        return self._ignore_revert_commits.value
+
+    @ignore_revert_commits.setter
+    @handle_option_error
+    def ignore_revert_commits(self, value):
+        return self._ignore_revert_commits.set(value)
+
+    @property
+    def debug(self):
+        return self._debug.value
+
+    @debug.setter
+    @handle_option_error
+    def debug(self, value):
+        return self._debug.set(value)
+
+    @property
+    def ignore(self):
+        return self._ignore.value
+
+    @ignore.setter
+    def ignore(self, value):
+        if value == "all":
+            value = [rule.id for rule in self.rules]
+        return self._ignore.set(value)
+
+    @property
+    def ignore_stdin(self):
+        return self._ignore_stdin.value
+
+    @ignore_stdin.setter
+    @handle_option_error
+    def ignore_stdin(self, value):
+        return self._ignore_stdin.set(value)
+
+    @property
+    def staged(self):
+        return self._staged.value
+
+    @staged.setter
+    @handle_option_error
+    def staged(self, value):
+        return self._staged.set(value)
+
+    @property
+    def fail_without_commits(self):
+        return self._fail_without_commits.value
+
+    @fail_without_commits.setter
+    @handle_option_error
+    def fail_without_commits(self, value):
+        return self._fail_without_commits.set(value)
+
+    @property
+    def regex_style_search(self):
+        return self._regex_style_search.value
+
+    @regex_style_search.setter
+    @handle_option_error
+    def regex_style_search(self, value):
+        return self._regex_style_search.set(value)
+
+    @property
+    def extra_path(self):
+        return self._extra_path.value if self._extra_path else None
+
+    @extra_path.setter
+    def extra_path(self, value):
+        try:
+            if self.extra_path:
+                self._extra_path.set(value)
+            else:
+                self._extra_path = options.PathOption(
+                    "extra-path", value, "Path to a directory or module with extra user-defined rules", type="both"
+                )
+
+            # Make sure we unload any previously loaded extra-path rules
+            self.rules.delete_rules_by_attr("is_user_defined", True)
+
+            # Find rules in the new extra-path and add them to the existing rules
+            rule_classes = rule_finder.find_rule_classes(self.extra_path)
+            self.rules.add_rules(rule_classes, {"is_user_defined": True})
+
+        except (options.RuleOptionError, rules.UserRuleError) as e:
+            raise LintConfigError(str(e)) from e
+
+    @property
+    def contrib(self):
+        return self._contrib.value
+
+    @contrib.setter
+    def contrib(self, value):
+        try:
+            self._contrib.set(value)
+
+            # Make sure we unload any previously loaded contrib rules when re-setting the value
+            self.rules.delete_rules_by_attr("is_contrib", True)
+
+            # Load all classes from the contrib directory
+            contrib_dir_path = os.path.dirname(os.path.realpath(contrib_rules.__file__))
+            rule_classes = rule_finder.find_rule_classes(contrib_dir_path)
+
+            # For each specified contrib rule, check whether it exists among the contrib classes
+            for rule_id_or_name in self.contrib:
+                rule_class = next((rc for rc in rule_classes if rule_id_or_name in (rc.id, rc.name)), False)
+
+                # If contrib rule exists, instantiate it and add it to the rules list
+                if rule_class:
+                    self.rules.add_rule(rule_class, rule_class.id, {"is_contrib": True})
+                else:
+                    raise LintConfigError(f"No contrib rule with id or name '{rule_id_or_name}' found.")
+
+        except (options.RuleOptionError, rules.UserRuleError) as e:
+            raise LintConfigError(str(e)) from e
+
+    def _get_option(self, rule_name_or_id, option_name):
+        rule = self.rules.find_rule(rule_name_or_id)
+        if not rule:
+            raise LintConfigError(f"No such rule '{rule_name_or_id}'")
+
+        option = rule.options.get(option_name)
+        if not option:
+            raise LintConfigError(f"Rule '{rule_name_or_id}' has no option '{option_name}'")
+
+        return option
+
+    def get_rule_option(self, rule_name_or_id, option_name):
+        """Returns the value of a given option for a given rule. LintConfigErrors will be raised if the
+        rule or option don't exist."""
+        option = self._get_option(rule_name_or_id, option_name)
+        return option.value
+
+    def set_rule_option(self, rule_name_or_id, option_name, option_value):
+        """Attempts to set a given value for a given option for a given rule.
+        LintConfigErrors will be raised if the rule or option don't exist or if the value is invalid."""
+        option = self._get_option(rule_name_or_id, option_name)
+        try:
+            option.set(option_value)
+        except options.RuleOptionError as e:
+            msg = f"'{option_value}' is not a valid value for option '{rule_name_or_id}.{option_name}'. {e}."
+            raise LintConfigError(msg) from e
+
+    def set_general_option(self, option_name, option_value):
+        attr_name = option_name.replace("-", "_")
+        # only allow setting general options that exist and don't start with an underscore
+        if not hasattr(self, attr_name) or attr_name[0] == "_":
+            raise LintConfigError(f"'{option_name}' is not a valid gitlint option")
+
+        # else
+        setattr(self, attr_name, option_value)
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, LintConfig)
+            and self.rules == other.rules
+            and self.verbosity == other.verbosity
+            and self.target == other.target
+            and self.extra_path == other.extra_path
+            and self.contrib == other.contrib
+            and self.ignore_merge_commits == other.ignore_merge_commits
+            and self.ignore_fixup_commits == other.ignore_fixup_commits
+            and self.ignore_fixup_amend_commits == other.ignore_fixup_amend_commits
+            and self.ignore_squash_commits == other.ignore_squash_commits
+            and self.ignore_revert_commits == other.ignore_revert_commits
+            and self.ignore_stdin == other.ignore_stdin
+            and self.staged == other.staged
+            and self.fail_without_commits == other.fail_without_commits
+            and self.regex_style_search == other.regex_style_search
+            and self.debug == other.debug
+            and self.ignore == other.ignore
+            and self._config_path == other._config_path
+        )
+
+    def __str__(self):
+        # config-path is not a user exposed variable, so don't print it under the general section
+        return (
+            f"config-path: {self._config_path}\n"
+            "[GENERAL]\n"
+            f"extra-path: {self.extra_path}\n"
+            f"contrib: {self.contrib}\n"
+            f"ignore: {','.join(self.ignore)}\n"
+            f"ignore-merge-commits: {self.ignore_merge_commits}\n"
+            f"ignore-fixup-commits: {self.ignore_fixup_commits}\n"
+            f"ignore-fixup-amend-commits: {self.ignore_fixup_amend_commits}\n"
+            f"ignore-squash-commits: {self.ignore_squash_commits}\n"
+            f"ignore-revert-commits: {self.ignore_revert_commits}\n"
+            f"ignore-stdin: {self.ignore_stdin}\n"
+            f"staged: {self.staged}\n"
+            f"fail-without-commits: {self.fail_without_commits}\n"
+            f"regex-style-search: {self.regex_style_search}\n"
+            f"verbosity: {self.verbosity}\n"
+            f"debug: {self.debug}\n"
+            f"target: {self.target}\n"
+            f"[RULES]\n{self.rules}"
+        )
+
+
+class RuleCollection:
+    """Class representing an ordered list of rules. Methods are provided to easily retrieve, add or delete rules."""
+
+    def __init__(self, rule_classes=None, rule_attrs=None):
+        # Use an ordered dict so that the order in which rules are applied is always the same
+        self._rules = OrderedDict()
+        if rule_classes:
+            self.add_rules(rule_classes, rule_attrs)
+
+    def find_rule(self, rule_id_or_name):
+        rule = self._rules.get(rule_id_or_name)
+        # if not found, try finding rule by name
+        if not rule:
+            rule = next((rule for rule in self._rules.values() if rule.name == rule_id_or_name), None)
+        return rule
+
+    def add_rule(self, rule_class, rule_id, rule_attrs=None):
+        """Instantiates and adds a rule to RuleCollection.
+        Note: There can be multiple instantiations of the same rule_class in the RuleCollection, as long as the
+        rule_id is unique.
+        :param rule_class python class representing the rule
+        :param rule_id unique identifier for the rule. If not unique, it will
+                       overwrite the existing rule with that id
+        :param rule_attrs dictionary of attributes to set on the instantiated rule obj
+        """
+        rule_obj = rule_class()
+        rule_obj.id = rule_id
+        if rule_attrs:
+            for key, val in rule_attrs.items():
+                setattr(rule_obj, key, val)
+        self._rules[rule_obj.id] = rule_obj
+
+    def add_rules(self, rule_classes, rule_attrs=None):
+        """Convenience method to add multiple rules at once based on a list of rule classes."""
+        for rule_class in rule_classes:
+            self.add_rule(rule_class, rule_class.id, rule_attrs)
+
+    def delete_rules_by_attr(self, attr_name, attr_val):
+        """Deletes all rules from the collection that match a given attribute name and value"""
+        # Create a new list based on _rules.values() because in python 3, values() is a ValuesView as opposed to a list
+        # This means you can't modify the ValueView while iterating over it.
+        for rule in list(self._rules.values()):
+            if hasattr(rule, attr_name) and (getattr(rule, attr_name) == attr_val):
+                del self._rules[rule.id]
+
+    def __iter__(self):
+        yield from self._rules.values()
+
+    def __eq__(self, other):
+        return isinstance(other, RuleCollection) and self._rules == other._rules
+
+    def __len__(self):
+        return len(self._rules)
+
+    def __str__(self):
+        return_str = ""
+        for rule in self._rules.values():
+            return_str += f"  {rule.id}: {rule.name}\n"
+            for option_name, option_value in sorted(rule.options.items()):
+                if option_value.value is None:
+                    option_val_repr = None
+                elif isinstance(option_value.value, list):
+                    option_val_repr = ",".join(option_value.value)
+                elif isinstance(option_value, options.RegexOption):
+                    option_val_repr = option_value.value.pattern
+                else:
+                    option_val_repr = option_value.value
+                return_str += f"     {option_name}={option_val_repr}\n"
+        return return_str
+
+
+class LintConfigBuilder:
+    """Factory class that can build gitlint config.
+    This is primarily useful to deal with complex configuration scenarios where configuration can be set and overridden
+    from various sources (typically according to certain precedence rules) before the actual config should be
+    normalized, validated and build. Example usage can be found in gitlint.cli.
+    """
+
+    RULE_QUALIFIER_SYMBOL = ":"
+
+    def __init__(self):
+        self._config_blueprint = OrderedDict()
+        self._config_path = None
+
+    def set_option(self, section, option_name, option_value):
+        if section not in self._config_blueprint:
+            self._config_blueprint[section] = OrderedDict()
+        self._config_blueprint[section][option_name] = option_value
+
+    def set_config_from_commit(self, commit):
+        """Given a git commit, applies config specified in the commit message.
+        Supported:
+         - gitlint-ignore: all
+        """
+        for line in commit.message.body:
+            pattern = re.compile(r"^gitlint-ignore:\s*(.*)")
+            matches = pattern.match(line)
+            if matches and len(matches.groups()) == 1:
+                self.set_option("general", "ignore", matches.group(1))
+
+    def set_config_from_string_list(self, config_options):
+        """Given a list of config options of the form "<rule>.<option>=<value>", parses out the correct rule and option
+        and sets the value accordingly in this factory object."""
+        for config_option in config_options:
+            try:
+                config_name, option_value = config_option.split("=", 1)
+                if not option_value:
+                    raise ValueError()
+                rule_name, option_name = config_name.split(".", 1)
+                self.set_option(rule_name, option_name, option_value)
+            except ValueError as e:  # raised if the config string is invalid
+                raise LintConfigError(
+                    f"'{config_option}' is an invalid configuration option. Use '<rule>.<option>=<value>'"
+                ) from e
+
+    def set_from_config_file(self, filename):
+        """Loads lint config from an ini-style config file"""
+        if not os.path.exists(filename):
+            raise LintConfigError(f"Invalid file path: {filename}")
+        self._config_path = os.path.realpath(filename)
+        try:
+            parser = ConfigParser()
+
+            with open(filename, encoding=FILE_ENCODING) as config_file:
+                parser.read_file(config_file, filename)
+
+            for section_name in parser.sections():
+                for option_name, option_value in parser.items(section_name):
+                    self.set_option(section_name, option_name, str(option_value))
+
+        except ConfigParserError as e:
+            raise LintConfigError(str(e)) from e
+
+    def _add_named_rule(self, config, qualified_rule_name):
+        """Adds a Named Rule to a given LintConfig object.
+        IMPORTANT: This method does *NOT* overwrite existing Named Rules with the same canonical id.
+        """
+
+        # Split up named rule in its parts: the name/id that specifies the parent rule,
+        # And the name of the rule instance itself
+        rule_name_parts = qualified_rule_name.split(self.RULE_QUALIFIER_SYMBOL, 1)
+        rule_name = rule_name_parts[1].strip()
+        parent_rule_specifier = rule_name_parts[0].strip()
+
+        # assert that the rule name is valid:
+        # - not empty
+        # - no whitespace or colons
+        if rule_name == "" or bool(re.search("\\s|:", rule_name, re.UNICODE)):
+            msg = f"The rule-name part in '{qualified_rule_name}' cannot contain whitespace, colons or be empty"
+            raise LintConfigError(msg)
+
+        # find parent rule
+        parent_rule = config.rules.find_rule(parent_rule_specifier)
+        if not parent_rule:
+            msg = f"No such rule '{parent_rule_specifier}' (named rule: '{qualified_rule_name}')"
+            raise LintConfigError(msg)
+
+        # Determine canonical id and name by recombining the parent id/name and instance name parts.
+        canonical_id = parent_rule.__class__.id + self.RULE_QUALIFIER_SYMBOL + rule_name
+        canonical_name = parent_rule.__class__.name + self.RULE_QUALIFIER_SYMBOL + rule_name
+
+        # Add the rule to the collection of rules if it's not there already
+        if not config.rules.find_rule(canonical_id):
+            config.rules.add_rule(parent_rule.__class__, canonical_id, {"is_named": True, "name": canonical_name})
+
+        return canonical_id
+
+    def build(self, config=None):
+        """Build a real LintConfig object by normalizing and validating the options that were previously set on this
+        factory."""
+        # If we are passed a config object, then rebuild that object instead of building a new lintconfig object from
+        # scratch
+        if not config:
+            config = LintConfig()
+
+        config._config_path = self._config_path
+
+        # Set general options first as this might change the behavior or validity of the other options
+        general_section = self._config_blueprint.get("general")
+        if general_section:
+            for option_name, option_value in general_section.items():
+                config.set_general_option(option_name, option_value)
+
+        for section_name, section_dict in self._config_blueprint.items():
+            for option_name, option_value in section_dict.items():
+                qualified_section_name = section_name
+                # Skip over the general section, as we've already done that above
+                if qualified_section_name != "general":
+                    # If the section name contains a colon (:), then this section is defining a Named Rule
+                    # Which means we need to instantiate that Named Rule in the config.
+                    if self.RULE_QUALIFIER_SYMBOL in section_name:
+                        qualified_section_name = self._add_named_rule(config, qualified_section_name)
+
+                    config.set_rule_option(qualified_section_name, option_name, option_value)
+
+        return config
+
+    def clone(self):
+        """Creates an exact copy of a LintConfigBuilder."""
+        builder = LintConfigBuilder()
+        builder._config_blueprint = copy.deepcopy(self._config_blueprint)
+        builder._config_path = self._config_path
+        return builder
+
+
+GITLINT_CONFIG_TEMPLATE_SRC_PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)), "files/gitlint")
+
+
+class LintConfigGenerator:
+    @staticmethod
+    def generate_config(dest):
+        """Generates a gitlint config file at the given destination location.
+        Expects that the given ```dest``` points to a valid destination."""
+        shutil.copyfile(GITLINT_CONFIG_TEMPLATE_SRC_PATH, dest)
diff --git a/gitlint-core/gitlint/contrib/__init__.py b/gitlint-core/gitlint/contrib/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/gitlint-core/gitlint/contrib/rules/__init__.py b/gitlint-core/gitlint/contrib/rules/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/gitlint-core/gitlint/contrib/rules/authors_commit.py b/gitlint-core/gitlint/contrib/rules/authors_commit.py
new file mode 100644
index 0000000..5c4a150
--- /dev/null
+++ b/gitlint-core/gitlint/contrib/rules/authors_commit.py
@@ -0,0 +1,45 @@
+import re
+from pathlib import Path
+from typing import Tuple
+
+from gitlint.rules import CommitRule, RuleViolation
+
+
+class AllowedAuthors(CommitRule):
+    """Enforce that only authors listed in the AUTHORS file are allowed to commit."""
+
+    authors_file_names = ("AUTHORS", "AUTHORS.txt", "AUTHORS.md")
+    parse_authors = re.compile(r"^(?P<name>.*) <(?P<email>.*)>$", re.MULTILINE)
+
+    name = "contrib-allowed-authors"
+
+    id = "CC3"
+
+    @classmethod
+    def _read_authors_from_file(cls, git_ctx) -> Tuple[str, str]:
+        for file_name in cls.authors_file_names:
+            path = Path(git_ctx.repository_path) / file_name
+            if path.exists():
+                authors_file = path
+                break
+        else:
+            raise FileNotFoundError("No AUTHORS file found!")
+
+        authors_file_content = authors_file.read_text("utf-8")
+        authors = re.findall(cls.parse_authors, authors_file_content)
+
+        return set(authors), authors_file.name
+
+    def validate(self, commit):
+        registered_authors, authors_file_name = AllowedAuthors._read_authors_from_file(commit.message.context)
+
+        author = (commit.author_name, commit.author_email.lower())
+
+        if author not in registered_authors:
+            return [
+                RuleViolation(
+                    self.id,
+                    f"Author not in '{authors_file_name}' file: " f'"{commit.author_name} <{commit.author_email}>"',
+                )
+            ]
+        return []
diff --git a/gitlint-core/gitlint/contrib/rules/conventional_commit.py b/gitlint-core/gitlint/contrib/rules/conventional_commit.py
new file mode 100644
index 0000000..705b083
--- /dev/null
+++ b/gitlint-core/gitlint/contrib/rules/conventional_commit.py
@@ -0,0 +1,37 @@
+import re
+
+from gitlint.options import ListOption
+from gitlint.rules import CommitMessageTitle, LineRule, RuleViolation
+
+RULE_REGEX = re.compile(r"([^(]+?)(\([^)]+?\))?!?: .+")
+
+
+class ConventionalCommit(LineRule):
+    """This rule enforces the spec at https://www.conventionalcommits.org/."""
+
+    name = "contrib-title-conventional-commits"
+    id = "CT1"
+    target = CommitMessageTitle
+
+    options_spec = [
+        ListOption(
+            "types",
+            ["fix", "feat", "chore", "docs", "style", "refactor", "perf", "test", "revert", "ci", "build"],
+            "Comma separated list of allowed commit types.",
+        )
+    ]
+
+    def validate(self, line, _commit):
+        violations = []
+        match = RULE_REGEX.match(line)
+
+        if not match:
+            msg = "Title does not follow ConventionalCommits.org format 'type(optional-scope): description'"
+            violations.append(RuleViolation(self.id, msg, line))
+        else:
+            line_commit_type = match.group(1)
+            if line_commit_type not in self.options["types"].value:
+                opt_str = ", ".join(self.options["types"].value)
+                violations.append(RuleViolation(self.id, f"Title does not start with one of {opt_str}", line))
+
+        return violations
diff --git a/gitlint-core/gitlint/contrib/rules/disallow_cleanup_commits.py b/gitlint-core/gitlint/contrib/rules/disallow_cleanup_commits.py
new file mode 100644
index 0000000..7f62dee
--- /dev/null
+++ b/gitlint-core/gitlint/contrib/rules/disallow_cleanup_commits.py
@@ -0,0 +1,22 @@
+from gitlint.rules import CommitRule, RuleViolation
+
+
+class DisallowCleanupCommits(CommitRule):
+    """This rule checks the commits for "fixup!"/"squash!"/"amend!" commits
+    and rejects them.
+    """
+
+    name = "contrib-disallow-cleanup-commits"
+    id = "CC2"
+
+    def validate(self, commit):
+        if commit.is_fixup_commit:
+            return [RuleViolation(self.id, "Fixup commits are not allowed", line_nr=1)]
+
+        if commit.is_squash_commit:
+            return [RuleViolation(self.id, "Squash commits are not allowed", line_nr=1)]
+
+        if commit.is_fixup_amend_commit:
+            return [RuleViolation(self.id, "Amend commits are not allowed", line_nr=1)]
+
+        return []
diff --git a/gitlint-core/gitlint/contrib/rules/signedoff_by.py b/gitlint-core/gitlint/contrib/rules/signedoff_by.py
new file mode 100644
index 0000000..5ea8217
--- /dev/null
+++ b/gitlint-core/gitlint/contrib/rules/signedoff_by.py
@@ -0,0 +1,17 @@
+from gitlint.rules import CommitRule, RuleViolation
+
+
+class SignedOffBy(CommitRule):
+    """This rule will enforce that each commit body contains a "Signed-off-by" line.
+    We keep things simple here and just check whether the commit body contains a line that starts with "Signed-off-by".
+    """
+
+    name = "contrib-body-requires-signed-off-by"
+    id = "CC1"
+
+    def validate(self, commit):
+        for line in commit.message.body:
+            if line.lower().startswith("signed-off-by"):
+                return []
+
+        return [RuleViolation(self.id, "Body does not contain a 'Signed-off-by' line", line_nr=1)]
diff --git a/gitlint-core/gitlint/deprecation.py b/gitlint-core/gitlint/deprecation.py
new file mode 100644
index 0000000..b7c2f42
--- /dev/null
+++ b/gitlint-core/gitlint/deprecation.py
@@ -0,0 +1,39 @@
+import logging
+
+LOG = logging.getLogger("gitlint.deprecated")
+DEPRECATED_LOG_FORMAT = "%(levelname)s: %(message)s"
+
+
+class Deprecation:
+    """Singleton class that handles deprecation warnings and behavior."""
+
+    # LintConfig class that is used to determine deprecation behavior
+    config = None
+
+    # Set of warning messages that have already been logged, to prevent duplicate warnings
+    warning_msgs = set()
+
+    @classmethod
+    def get_regex_method(cls, rule, regex_option):
+        """Returns the regex method to be used for a given rule based on general.regex-style-search option.
+        Logs a warning if the deprecated re.match method is returned."""
+
+        # if general.regex-style-search is set, just return re.search
+        if cls.config.regex_style_search:
+            return regex_option.value.search
+
+        warning_msg = (
+            f"{rule.id} - {rule.name}: gitlint will be switching from using Python regex 'match' (match beginning) to "
+            "'search' (match anywhere) semantics. "
+            f"Please review your {rule.name}.regex option accordingly. "
+            "To remove this warning, set general.regex-style-search=True. "
+            "More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search"
+        )
+
+        # Only log warnings once
+        if warning_msg not in cls.warning_msgs:
+            log = logging.getLogger("gitlint.deprecated.regex_style_search")
+            log.warning(warning_msg)
+        cls.warning_msgs.add(warning_msg)
+
+        return regex_option.value.match
diff --git a/gitlint-core/gitlint/display.py b/gitlint-core/gitlint/display.py
new file mode 100644
index 0000000..1de8d08
--- /dev/null
+++ b/gitlint-core/gitlint/display.py
@@ -0,0 +1,36 @@
+from sys import stderr, stdout
+
+
+class Display:
+    """Utility class to print stuff to an output stream (stdout by default) based on the config's verbosity"""
+
+    def __init__(self, lint_config):
+        self.config = lint_config
+
+    def _output(self, message, verbosity, exact, stream):
+        """Output a message if the config's verbosity is >= to the given verbosity. If exact == True, the message
+        will only be outputted if the given verbosity exactly matches the config's verbosity."""
+        if exact:
+            if self.config.verbosity == verbosity:
+                stream.write(message + "\n")
+        else:
+            if self.config.verbosity >= verbosity:
+                stream.write(message + "\n")
+
+    def v(self, message, exact=False):
+        self._output(message, 1, exact, stdout)
+
+    def vv(self, message, exact=False):
+        self._output(message, 2, exact, stdout)
+
+    def vvv(self, message, exact=False):
+        self._output(message, 3, exact, stdout)
+
+    def e(self, message, exact=False):
+        self._output(message, 1, exact, stderr)
+
+    def ee(self, message, exact=False):
+        self._output(message, 2, exact, stderr)
+
+    def eee(self, message, exact=False):
+        self._output(message, 3, exact, stderr)
diff --git a/gitlint-core/gitlint/exception.py b/gitlint-core/gitlint/exception.py
new file mode 100644
index 0000000..d1e8c9c
--- /dev/null
+++ b/gitlint-core/gitlint/exception.py
@@ -0,0 +1,2 @@
+class GitlintError(Exception):
+    """Based Exception class for all gitlint exceptions"""
diff --git a/gitlint-core/gitlint/files/commit-msg b/gitlint-core/gitlint/files/commit-msg
new file mode 100644
index 0000000..e754e8d
--- /dev/null
+++ b/gitlint-core/gitlint/files/commit-msg
@@ -0,0 +1,35 @@
+#!/bin/sh
+### gitlint commit-msg hook start ###
+
+# Determine whether we have a tty available by trying to access it.
+# This allows us to deal with UI based gitclient's like Atlassian SourceTree.
+# NOTE: "exec < /dev/tty" sets stdin to the keyboard
+stdin_available=1
+(exec < /dev/tty) 2> /dev/null || stdin_available=0
+
+if [ $stdin_available -eq 1 ]; then
+    # Now that we know we have a functional tty, set stdin to it so we can ask the user questions :-)
+    exec < /dev/tty
+
+    # On Windows, we need to explicitly set our stdout to the tty to make terminal editing work (e.g. vim)
+    # See SO for windows detection in bash (slight modified to work on plain shell (not bash)): 
+    # https://stackoverflow.com/questions/394230/how-to-detect-the-os-from-a-bash-script
+    if [ "$OSTYPE" = "cygwin" ] || [ "$OSTYPE" = "msys" ] || [ "$OSTYPE" = "win32" ]; then
+        exec > /dev/tty
+    fi
+fi
+
+gitlint --staged --msg-filename "$1" run-hook
+exit_code=$?
+
+# If we fail to find the gitlint binary (command not found), let's retry by executing as a python module.
+# This is the case for Atlassian SourceTree, where $PATH deviates from the user's shell $PATH.
+if [ $exit_code -eq 127 ]; then
+    echo "Fallback to python module execution"
+    python -m gitlint.cli --staged --msg-filename "$1" run-hook
+    exit_code=$?
+fi
+
+exit $exit_code
+
+### gitlint commit-msg hook end ###
diff --git a/gitlint-core/gitlint/files/gitlint b/gitlint-core/gitlint/files/gitlint
new file mode 100644
index 0000000..3d9f273
--- /dev/null
+++ b/gitlint-core/gitlint/files/gitlint
@@ -0,0 +1,140 @@
+# Edit this file as you like.
+#
+# All these sections are optional. Each section with the exception of [general] represents
+# one rule and each key in it is an option for that specific rule.
+#
+# Rules and sections can be referenced by their full name or by id. For example
+# section "[body-max-line-length]" could also be written as "[B1]". Full section names are
+# used in here for clarity.
+#
+# [general]
+# Ignore certain rules, this example uses both full name and id
+# ignore=title-trailing-punctuation, T3
+
+# verbosity should be a value between 1 and 3, the commandline -v flags take precedence over this
+# verbosity = 2
+
+# By default gitlint will ignore merge, revert, fixup, fixup=amend, and squash commits. 
+# ignore-merge-commits=true
+# ignore-revert-commits=true
+# ignore-fixup-commits=true
+# ignore-fixup-amend-commits=true
+# ignore-squash-commits=true
+
+# Ignore any data sent to gitlint via stdin
+# ignore-stdin=true
+
+# Fetch additional meta-data from the local repository when manually passing a 
+# commit message to gitlint via stdin or --commit-msg. Disabled by default.
+# staged=true
+
+# Hard fail when the target commit range is empty. Note that gitlint will
+# already fail by default on invalid commit ranges. This option is specifically
+# to tell gitlint to fail on *valid but empty* commit ranges.
+# Disabled by default.
+# fail-without-commits=true
+
+# Whether to use Python `search` instead of `match` semantics in rules that use
+# regexes. Context: https://github.com/jorisroovers/gitlint/issues/254
+# Disabled by default, but will be enabled by default in the future.
+# regex-style-search=true
+
+# Enable debug mode (prints more output). Disabled by default.
+# debug=true
+
+# Enable community contributed rules
+# See http://jorisroovers.github.io/gitlint/contrib_rules for details
+# contrib=contrib-title-conventional-commits,CC1
+
+# Set the extra-path where gitlint will search for user defined rules
+# See http://jorisroovers.github.io/gitlint/user_defined_rules for details
+# extra-path=examples/
+
+# This is an example of how to configure the "title-max-length" rule and
+# set the line-length it enforces to 50
+# [title-max-length]
+# line-length=50
+
+# Conversely, you can also enforce minimal length of a title with the
+# "title-min-length" rule:
+# [title-min-length]
+# min-length=5
+
+# [title-must-not-contain-word]
+# Comma-separated list of words that should not occur in the title. Matching is case
+# insensitive. It's fine if the keyword occurs as part of a larger word (so "WIPING"
+# will not cause a violation, but "WIP: my title" will.
+# words=wip
+
+# [title-match-regex]
+# python-style regex that the commit-msg title must match
+# Note that the regex can contradict with other rules if not used correctly
+# (e.g. title-must-not-contain-word).
+# regex=^US[0-9]*
+
+# [body-max-line-length]
+# line-length=72
+
+# [body-min-length]
+# min-length=5
+
+# [body-is-missing]
+# Whether to ignore this rule on merge commits (which typically only have a title)
+# default = True
+# ignore-merge-commits=false
+
+# [body-changed-file-mention]
+# List of files that need to be explicitly mentioned in the body when they are changed
+# This is useful for when developers often erroneously edit certain files or git submodules.
+# By specifying this rule, developers can only change the file when they explicitly reference
+# it in the commit message.
+# files=gitlint-core/gitlint/rules.py,README.md
+
+# [body-match-regex]
+# python-style regex that the commit-msg body must match.
+# E.g. body must end in My-Commit-Tag: foo
+# regex=My-Commit-Tag: foo$
+
+# [author-valid-email]
+# python-style regex that the commit author email address must match.
+# For example, use the following regex if you only want to allow email addresses from foo.com
+# regex=[^@]+@foo.com
+
+# [ignore-by-title]
+# Ignore certain rules for commits of which the title matches a regex
+# E.g. Match commit titles that start with "Release"
+# regex=^Release(.*)
+
+# Ignore certain rules, you can reference them by their id or by their full name
+# Use 'all' to ignore all rules
+# ignore=T1,body-min-length
+
+# [ignore-by-body]
+# Ignore certain rules for commits of which the body has a line that matches a regex
+# E.g. Match bodies that have a line that that contain "release"
+# regex=(.*)release(.*)
+#
+# Ignore certain rules, you can reference them by their id or by their full name
+# Use 'all' to ignore all rules
+# ignore=T1,body-min-length
+
+# [ignore-body-lines]
+# Ignore certain lines in a commit body that match a regex.
+# E.g. Ignore all lines that start with 'Co-Authored-By'
+# regex=^Co-Authored-By
+
+# [ignore-by-author-name]
+# Ignore certain rules for commits of which the author name matches a regex
+# E.g. Match commits made by dependabot
+# regex=(.*)dependabot(.*)
+#
+# Ignore certain rules, you can reference them by their id or by their full name
+# Use 'all' to ignore all rules
+# ignore=T1,body-min-length
+
+# This is a contrib rule - a community contributed rule. These are disabled by default.
+# You need to explicitly enable them one-by-one by adding them to the "contrib" option
+# under [general] section above.
+# [contrib-title-conventional-commits]
+# Specify allowed commit types. For details see: https://www.conventionalcommits.org/
+# types = bugfix,user-story,epic
diff --git a/gitlint-core/gitlint/git.py b/gitlint-core/gitlint/git.py
new file mode 100644
index 0000000..6612a7d
--- /dev/null
+++ b/gitlint-core/gitlint/git.py
@@ -0,0 +1,510 @@
+import logging
+import os
+from pathlib import Path
+
+import arrow
+
+from gitlint import shell as sh
+from gitlint.cache import PropertyCache, cache
+from gitlint.exception import GitlintError
+
+# import exceptions separately, this makes it a little easier to mock them out in the unit tests
+from gitlint.shell import CommandNotFound, ErrorReturnCode
+
+# For now, the git date format we use is fixed, but technically this format is determined by `git config log.date`
+# We should fix this at some point :-)
+GIT_TIMEFORMAT = "YYYY-MM-DD HH:mm:ss Z"
+
+LOG = logging.getLogger(__name__)
+
+
+class GitContextError(GitlintError):
+    """Exception indicating there is an issue with the git context"""
+
+
+class GitNotInstalledError(GitContextError):
+    def __init__(self):
+        super().__init__(
+            "'git' command not found. You need to install git to use gitlint on a local repository. "
+            "See https://git-scm.com/book/en/v2/Getting-Started-Installing-Git on how to install git."
+        )
+
+
+class GitExitCodeError(GitContextError):
+    def __init__(self, command, stderr):
+        self.command = command
+        self.stderr = stderr
+        super().__init__(f"An error occurred while executing '{command}': {stderr}")
+
+
+def _git(*command_parts, **kwargs):
+    """Convenience function for running git commands. Automatically deals with exceptions and unicode."""
+    git_kwargs = {"_tty_out": False}
+    git_kwargs.update(kwargs)
+    try:
+        LOG.debug(command_parts)
+        result = sh.git(*command_parts, **git_kwargs)
+        # If we reach this point and the result has an exit_code that is larger than 0, this means that we didn't
+        # get an exception (which is the default sh behavior for non-zero exit codes) and so the user is expecting
+        # a non-zero exit code -> just return the entire result
+        if hasattr(result, "exit_code") and result.exit_code > 0:
+            return result
+        return str(result)
+    except CommandNotFound as e:
+        raise GitNotInstalledError from e
+    except ErrorReturnCode as e:  # Something went wrong while executing the git command
+        error_msg = e.stderr.strip()
+        error_msg_lower = error_msg.lower()
+        if "_cwd" in git_kwargs and b"not a git repository" in error_msg_lower:
+            raise GitContextError(f"{git_kwargs['_cwd']} is not a git repository.") from e
+
+        if (
+            b"does not have any commits yet" in error_msg_lower
+            or b"ambiguous argument 'head': unknown revision" in error_msg_lower
+        ):
+            msg = "Current branch has no commits. Gitlint requires at least one commit to function."
+            raise GitContextError(msg) from e
+
+        raise GitExitCodeError(e.full_cmd, error_msg) from e
+
+
+def git_version():
+    """Determine the git version installed on this host by calling git --version"""
+    return _git("--version").replace("\n", "")
+
+
+def git_commentchar(repository_path=None):
+    """Shortcut for retrieving comment char from git config"""
+    commentchar = _git("config", "--get", "core.commentchar", _cwd=repository_path, _ok_code=[0, 1])
+    # git will return an exit code of 1 if it can't find a config value, in this case we fall-back to # as commentchar
+    if hasattr(commentchar, "exit_code") and commentchar.exit_code == 1:
+        commentchar = "#"
+    return commentchar.replace("\n", "")
+
+
+def git_hooks_dir(repository_path):
+    """Determine hooks directory for a given target dir"""
+    hooks_dir = _git("rev-parse", "--git-path", "hooks", _cwd=repository_path)
+    hooks_dir = hooks_dir.replace("\n", "")
+    return os.path.realpath(os.path.join(repository_path, hooks_dir))
+
+
+def _parse_git_changed_file_stats(changed_files_stats_raw):
+    """Parse the output of git diff --numstat and return a dict of:
+    dict[filename: GitChangedFileStats(filename, additions, deletions)]"""
+    changed_files_stats_lines = changed_files_stats_raw.split("\n")
+    changed_files_stats = {}
+    for line in changed_files_stats_lines[:-1]:  # drop last empty line
+        line_stats = line.split()
+
+        # If the file is binary, numstat will show "-"
+        # See https://git-scm.com/docs/git-diff#Documentation/git-diff.txt---numstat
+        additions = int(line_stats[0]) if line_stats[0] != "-" else None
+        deletions = int(line_stats[1]) if line_stats[1] != "-" else None
+
+        changed_file_stat = GitChangedFileStats(line_stats[2], additions, deletions)
+        changed_files_stats[line_stats[2]] = changed_file_stat
+
+    return changed_files_stats
+
+
+class GitCommitMessage:
+    """Class representing a git commit message. A commit message consists of the following:
+    - context: The `GitContext` this commit message is part of
+    - original: The actual commit message as returned by `git log`
+    - full: original, but stripped of any comments
+    - title: the first line of full
+    - body: all lines following the title
+    """
+
+    def __init__(self, context, original=None, full=None, title=None, body=None):
+        self.context = context
+        self.original = original
+        self.full = full
+        self.title = title
+        self.body = body
+
+    @staticmethod
+    def from_full_message(context, commit_msg_str):
+        """Parses a full git commit message by parsing a given string into the different parts of a commit message"""
+        all_lines = commit_msg_str.splitlines()
+        cutline = f"{context.commentchar} ------------------------ >8 ------------------------"
+        try:
+            cutline_index = all_lines.index(cutline)
+        except ValueError:
+            cutline_index = None
+        lines = [line for line in all_lines[:cutline_index] if not line.startswith(context.commentchar)]
+        full = "\n".join(lines)
+        title = lines[0] if lines else ""
+        body = lines[1:] if len(lines) > 1 else []
+        return GitCommitMessage(context=context, original=commit_msg_str, full=full, title=title, body=body)
+
+    def __str__(self):
+        return self.full
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, GitCommitMessage)
+            and self.original == other.original
+            and self.full == other.full
+            and self.title == other.title
+            and self.body == other.body
+        )
+
+
+class GitChangedFileStats:
+    """Class representing the stats for a changed file in git"""
+
+    def __init__(self, filepath, additions, deletions):
+        self.filepath = Path(filepath)
+        self.additions = additions
+        self.deletions = deletions
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, GitChangedFileStats)
+            and self.filepath == other.filepath
+            and self.additions == other.additions
+            and self.deletions == other.deletions
+        )
+
+    def __str__(self) -> str:
+        return f"{self.filepath}: {self.additions} additions, {self.deletions} deletions"
+
+
+class GitCommit:
+    """Class representing a git commit.
+    A commit consists of: context, message, author name, author email, date, list of parent commit shas,
+    list of changed files, list of branch names.
+    In the context of gitlint, only the git context and commit message are required.
+    """
+
+    def __init__(
+        self,
+        context,
+        message,
+        sha=None,
+        date=None,
+        author_name=None,
+        author_email=None,
+        parents=None,
+        changed_files_stats=None,
+        branches=None,
+    ):
+        self.context = context
+        self.message = message
+        self.sha = sha
+        self.date = date
+        self.author_name = author_name
+        self.author_email = author_email
+        self.parents = parents or []  # parent commit hashes
+        self.changed_files_stats = changed_files_stats or {}
+        self.branches = branches or []
+
+    @property
+    def is_merge_commit(self):
+        return self.message.title.startswith("Merge")
+
+    @property
+    def is_fixup_commit(self):
+        return self.message.title.startswith("fixup!")
+
+    @property
+    def is_squash_commit(self):
+        return self.message.title.startswith("squash!")
+
+    @property
+    def is_fixup_amend_commit(self):
+        return self.message.title.startswith("amend!")
+
+    @property
+    def is_revert_commit(self):
+        return self.message.title.startswith("Revert")
+
+    @property
+    def changed_files(self):
+        return list(self.changed_files_stats.keys())
+
+    def __str__(self):
+        date_str = arrow.get(self.date).format(GIT_TIMEFORMAT) if self.date else None
+
+        if len(self.changed_files_stats) > 0:
+            changed_files_stats_str = "\n  " + "\n  ".join([str(stats) for stats in self.changed_files_stats.values()])
+        else:
+            changed_files_stats_str = " {}"
+
+        return (
+            f"--- Commit Message ----\n{self.message}\n"
+            "--- Meta info ---------\n"
+            f"Author: {self.author_name} <{self.author_email}>\n"
+            f"Date:   {date_str}\n"
+            f"is-merge-commit:  {self.is_merge_commit}\n"
+            f"is-fixup-commit:  {self.is_fixup_commit}\n"
+            f"is-fixup-amend-commit: {self.is_fixup_amend_commit}\n"
+            f"is-squash-commit: {self.is_squash_commit}\n"
+            f"is-revert-commit: {self.is_revert_commit}\n"
+            f"Parents: {self.parents}\n"
+            f"Branches: {self.branches}\n"
+            f"Changed Files: {self.changed_files}\n"
+            f"Changed Files Stats:{changed_files_stats_str}\n"
+            "-----------------------"
+        )
+
+    def __eq__(self, other):
+        # skip checking the context as context refers back to this obj, this will trigger a cyclic dependency
+        return (
+            isinstance(other, GitCommit)
+            and self.message == other.message
+            and self.sha == other.sha
+            and self.author_name == other.author_name
+            and self.author_email == other.author_email
+            and self.date == other.date
+            and self.parents == other.parents
+            and self.is_merge_commit == other.is_merge_commit
+            and self.is_fixup_commit == other.is_fixup_commit
+            and self.is_fixup_amend_commit == other.is_fixup_amend_commit
+            and self.is_squash_commit == other.is_squash_commit
+            and self.is_revert_commit == other.is_revert_commit
+            and self.changed_files == other.changed_files
+            and self.changed_files_stats == other.changed_files_stats
+            and self.branches == other.branches
+        )
+
+
+class LocalGitCommit(GitCommit, PropertyCache):
+    """Class representing a git commit that exists in the local git repository.
+    This class uses lazy loading: it defers reading information from the local git repository until the associated
+    property is accessed for the first time. Properties are then cached for subsequent access.
+
+    This approach ensures that we don't do 'expensive' git calls when certain properties are not actually used.
+    In addition, reading the required info when it's needed rather than up front avoids adding delay during gitlint
+    startup time and reduces gitlint's memory footprint.
+    """
+
+    def __init__(self, context, sha):
+        PropertyCache.__init__(self)
+        self.context = context
+        self.sha = sha
+
+    def _log(self):
+        """Does a call to `git log` to determine a bunch of information about the commit."""
+        long_format = "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B"
+        raw_commit = _git("log", self.sha, "-1", long_format, _cwd=self.context.repository_path).split("\n")
+
+        (name, email, date, parents), commit_msg = raw_commit[0].split("\x00"), "\n".join(raw_commit[1:])
+
+        commit_parents = [] if parents == "" else parents.split(" ")
+        commit_is_merge_commit = len(commit_parents) > 1
+
+        # "YYYY-MM-DD HH:mm:ss Z" -> ISO 8601-like format
+        # Use arrow for datetime parsing, because apparently python is quirky around ISO-8601 dates:
+        # http://stackoverflow.com/a/30696682/381010
+        commit_date = arrow.get(date, GIT_TIMEFORMAT).datetime
+
+        # Create Git commit object with the retrieved info
+        commit_msg_obj = GitCommitMessage.from_full_message(self.context, commit_msg)
+
+        self._cache.update(
+            {
+                "message": commit_msg_obj,
+                "author_name": name,
+                "author_email": email,
+                "date": commit_date,
+                "parents": commit_parents,
+                "is_merge_commit": commit_is_merge_commit,
+            }
+        )
+
+    @property
+    def message(self):
+        return self._try_cache("message", self._log)
+
+    @property
+    def author_name(self):
+        return self._try_cache("author_name", self._log)
+
+    @property
+    def author_email(self):
+        return self._try_cache("author_email", self._log)
+
+    @property
+    def date(self):
+        return self._try_cache("date", self._log)
+
+    @property
+    def parents(self):
+        return self._try_cache("parents", self._log)
+
+    @property
+    def branches(self):
+        def cache_branches():
+            # We have to parse 'git branch --contains <sha>' instead of 'git for-each-ref' to be compatible with
+            # git versions < 2.7.0
+            # https://stackoverflow.com/questions/45173979/can-i-force-git-branch-contains-tag-to-not-print-the-asterisk
+            branches = _git("branch", "--contains", self.sha, _cwd=self.context.repository_path).split("\n")
+
+            # This means that we need to remove any leading * that indicates the current branch. Note that we can
+            # safely do this since git branches cannot contain '*' anywhere, so if we find an '*' we know it's output
+            # from the git CLI and not part of the branch name. See https://git-scm.com/docs/git-check-ref-format
+            # We also drop the last empty line from the output.
+            self._cache["branches"] = [branch.replace("*", "").strip() for branch in branches[:-1]]
+
+        return self._try_cache("branches", cache_branches)
+
+    @property
+    def is_merge_commit(self):
+        return self._try_cache("is_merge_commit", self._log)
+
+    @property
+    def changed_files_stats(self):
+        def cache_changed_files_stats():
+            changed_files_stats_raw = _git(
+                "diff-tree", "--no-commit-id", "--numstat", "-r", "--root", self.sha, _cwd=self.context.repository_path
+            )
+            self._cache["changed_files_stats"] = _parse_git_changed_file_stats(changed_files_stats_raw)
+
+        return self._try_cache("changed_files_stats", cache_changed_files_stats)
+
+
+class StagedLocalGitCommit(GitCommit, PropertyCache):
+    """Class representing a git commit that has been staged, but not committed.
+
+    Other than the commit message itself (and changed files), a lot of information is actually not known at staging
+    time, since the commit hasn't happened yet. However, we can make educated guesses based on existing repository
+    information.
+    """
+
+    def __init__(self, context, commit_message):
+        PropertyCache.__init__(self)
+        self.context = context
+        self.message = commit_message
+        self.sha = None
+        self.parents = []  # Not really possible to determine before a commit
+
+    @property
+    @cache
+    def author_name(self):
+        try:
+            return _git("config", "--get", "user.name", _cwd=self.context.repository_path).strip()
+        except GitExitCodeError as e:
+            raise GitContextError("Missing git configuration: please set user.name") from e
+
+    @property
+    @cache
+    def author_email(self):
+        try:
+            return _git("config", "--get", "user.email", _cwd=self.context.repository_path).strip()
+        except GitExitCodeError as e:
+            raise GitContextError("Missing git configuration: please set user.email") from e
+
+    @property
+    @cache
+    def date(self):
+        # We don't know the actual commit date yet, but we make a pragmatic trade-off here by providing the current date
+        # We get current date from arrow, reformat in git date format, then re-interpret it as a date.
+        # This ensure we capture the same precision and timezone information that git does.
+        return arrow.get(arrow.now().format(GIT_TIMEFORMAT), GIT_TIMEFORMAT).datetime
+
+    @property
+    @cache
+    def branches(self):
+        # We don't know the branch this commit will be part of yet, but we're pragmatic here and just return the
+        # current branch, as for all intents and purposes, this will be what the user is looking for.
+        return [self.context.current_branch]
+
+    @property
+    def changed_files_stats(self):
+        def cache_changed_files_stats():
+            changed_files_stats_raw = _git("diff", "--staged", "--numstat", "-r", _cwd=self.context.repository_path)
+            self._cache["changed_files_stats"] = _parse_git_changed_file_stats(changed_files_stats_raw)
+
+        return self._try_cache("changed_files_stats", cache_changed_files_stats)
+
+
+class GitContext(PropertyCache):
+    """Class representing the git context in which gitlint is operating: a data object storing information about
+    the git repository that gitlint is linting.
+    """
+
+    def __init__(self, repository_path=None):
+        PropertyCache.__init__(self)
+        self.commits = []
+        self.repository_path = repository_path
+
+    @property
+    @cache
+    def commentchar(self):
+        return git_commentchar(self.repository_path)
+
+    @property
+    @cache
+    def current_branch(self):
+        try:
+            current_branch = _git("rev-parse", "--abbrev-ref", "HEAD", _cwd=self.repository_path).strip()
+        except GitContextError:
+            # Maybe there is no commit.  Try another way to get current branch (need Git 2.22+)
+            current_branch = _git("branch", "--show-current", _cwd=self.repository_path).strip()
+        return current_branch
+
+    @staticmethod
+    def from_commit_msg(commit_msg_str):
+        """Determines git context based on a commit message.
+        :param commit_msg_str: Full git commit message.
+        """
+        context = GitContext()
+        commit_msg_obj = GitCommitMessage.from_full_message(context, commit_msg_str)
+        commit = GitCommit(context, commit_msg_obj)
+        context.commits.append(commit)
+        return context
+
+    @staticmethod
+    def from_staged_commit(commit_msg_str, repository_path):
+        """Determines git context based on a commit message that is a staged commit for a local git repository.
+        :param commit_msg_str: Full git commit message.
+        :param repository_path: Path to the git repository to retrieve the context from
+        """
+        context = GitContext(repository_path=repository_path)
+        commit_msg_obj = GitCommitMessage.from_full_message(context, commit_msg_str)
+        commit = StagedLocalGitCommit(context, commit_msg_obj)
+        context.commits.append(commit)
+        return context
+
+    @staticmethod
+    def from_local_repository(repository_path, refspec=None, commit_hashes=None):
+        """Retrieves the git context from a local git repository.
+        :param repository_path: Path to the git repository to retrieve the context from
+        :param refspec: The commit(s) to retrieve (mutually exclusive with `commit_hash`)
+        :param commit_hash: Hash of the commit to retrieve (mutually exclusive with `refspec`)
+        """
+
+        context = GitContext(repository_path=repository_path)
+
+        if refspec:
+            sha_list = _git("rev-list", refspec, _cwd=repository_path).split()
+        elif commit_hashes:  # One or more commit hashes, just pass it to `git log -1`
+            # Even though we have already been passed the commit hash, we ask git to retrieve this hash and
+            # return it to us. This way we verify that the passed hash is a valid hash for the target repo and we
+            # also convert it to the full hash format (we might have been passed a short hash).
+            sha_list = []
+            for commit_hash in commit_hashes:
+                sha_list.append(_git("log", "-1", commit_hash, "--pretty=%H", _cwd=repository_path).replace("\n", ""))
+        else:  # If no refspec is defined, fallback to the last commit on the current branch
+            # We tried many things here e.g.: defaulting to e.g. HEAD or HEAD^... (incl. dealing with
+            # repos that only have a single commit - HEAD^... doesn't work there), but then we still get into
+            # problems with e.g. merge commits. Easiest solution is just taking the SHA from `git log -1`.
+            sha_list = [_git("log", "-1", "--pretty=%H", _cwd=repository_path).replace("\n", "")]
+
+        for sha in sha_list:
+            commit = LocalGitCommit(context, sha)
+            context.commits.append(commit)
+
+        return context
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, GitContext)
+            and self.commits == other.commits
+            and self.repository_path == other.repository_path
+            and self.commentchar == other.commentchar
+            and self.current_branch == other.current_branch
+        )
diff --git a/gitlint-core/gitlint/hooks.py b/gitlint-core/gitlint/hooks.py
new file mode 100644
index 0000000..98ded18
--- /dev/null
+++ b/gitlint-core/gitlint/hooks.py
@@ -0,0 +1,65 @@
+import os
+import shutil
+import stat
+
+from gitlint.exception import GitlintError
+from gitlint.git import git_hooks_dir
+from gitlint.utils import FILE_ENCODING
+
+COMMIT_MSG_HOOK_SRC_PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)), "files", "commit-msg")
+COMMIT_MSG_HOOK_DST_PATH = "commit-msg"
+GITLINT_HOOK_IDENTIFIER = "### gitlint commit-msg hook start ###\n"
+
+
+class GitHookInstallerError(GitlintError):
+    pass
+
+
+class GitHookInstaller:
+    """Utility class that provides methods for installing and uninstalling the gitlint commitmsg hook."""
+
+    @staticmethod
+    def commit_msg_hook_path(lint_config):
+        return os.path.join(git_hooks_dir(lint_config.target), COMMIT_MSG_HOOK_DST_PATH)
+
+    @staticmethod
+    def _assert_git_repo(target):
+        """Asserts that a given target directory is a git repository"""
+        hooks_dir = git_hooks_dir(target)
+        if not os.path.isdir(hooks_dir):
+            raise GitHookInstallerError(f"{target} is not a git repository.")
+
+    @staticmethod
+    def install_commit_msg_hook(lint_config):
+        GitHookInstaller._assert_git_repo(lint_config.target)
+        dest_path = GitHookInstaller.commit_msg_hook_path(lint_config)
+        if os.path.exists(dest_path):
+            raise GitHookInstallerError(
+                f"There is already a commit-msg hook file present in {dest_path}.\n"
+                "gitlint currently does not support appending to an existing commit-msg file."
+            )
+
+        # copy hook file
+        shutil.copy(COMMIT_MSG_HOOK_SRC_PATH, dest_path)
+        # make hook executable
+        st = os.stat(dest_path)
+        os.chmod(dest_path, st.st_mode | stat.S_IEXEC)
+
+    @staticmethod
+    def uninstall_commit_msg_hook(lint_config):
+        GitHookInstaller._assert_git_repo(lint_config.target)
+        dest_path = GitHookInstaller.commit_msg_hook_path(lint_config)
+        if not os.path.exists(dest_path):
+            raise GitHookInstallerError(f"There is no commit-msg hook present in {dest_path}.")
+
+        with open(dest_path, encoding=FILE_ENCODING) as fp:
+            lines = fp.readlines()
+            if len(lines) < 2 or lines[1] != GITLINT_HOOK_IDENTIFIER:  # noqa: PLR2004 (Magic value used in comparison)
+                msg = (
+                    f"The commit-msg hook in {dest_path} was not installed by gitlint (or it was modified).\n"
+                    "Uninstallation of 3th party or modified gitlint hooks is not supported."
+                )
+                raise GitHookInstallerError(msg)
+
+        # If we are sure it's a gitlint hook, go ahead and remove it
+        os.remove(dest_path)
diff --git a/gitlint-core/gitlint/lint.py b/gitlint-core/gitlint/lint.py
new file mode 100644
index 0000000..420d3ad
--- /dev/null
+++ b/gitlint-core/gitlint/lint.py
@@ -0,0 +1,123 @@
+import logging
+
+from gitlint import display
+from gitlint import rules as gitlint_rules
+from gitlint.deprecation import Deprecation
+
+LOG = logging.getLogger(__name__)
+logging.basicConfig()
+
+
+class GitLinter:
+    """Main linter class. This is where rules actually get applied. See the lint() method."""
+
+    def __init__(self, config):
+        self.config = config
+
+        self.display = display.Display(config)
+
+    def should_ignore_rule(self, rule):
+        """Determines whether a rule should be ignored based on the general list of commits to ignore"""
+        return rule.id in self.config.ignore or rule.name in self.config.ignore
+
+    @property
+    def configuration_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.ConfigurationRule) and not self.should_ignore_rule(rule)
+        ]
+
+    @property
+    def title_line_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.LineRule)
+            and rule.target == gitlint_rules.CommitMessageTitle
+            and not self.should_ignore_rule(rule)
+        ]
+
+    @property
+    def body_line_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.LineRule)
+            and rule.target == gitlint_rules.CommitMessageBody
+            and not self.should_ignore_rule(rule)
+        ]
+
+    @property
+    def commit_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.CommitRule) and not self.should_ignore_rule(rule)
+        ]
+
+    @staticmethod
+    def _apply_line_rules(lines, commit, rules, line_nr_start):
+        """Iterates over the lines in a given list of lines and validates a given list of rules against each line"""
+        all_violations = []
+        line_nr = line_nr_start
+        for line in lines:
+            for rule in rules:
+                violations = rule.validate(line, commit)
+                if violations:
+                    for violation in violations:
+                        violation.line_nr = line_nr
+                        all_violations.append(violation)
+            line_nr += 1
+        return all_violations
+
+    @staticmethod
+    def _apply_commit_rules(rules, commit):
+        """Applies a set of rules against a given commit and gitcontext"""
+        all_violations = []
+        for rule in rules:
+            violations = rule.validate(commit)
+            if violations:
+                all_violations.extend(violations)
+        return all_violations
+
+    def lint(self, commit):
+        """Lint the last commit in a given git context by applying all ignore, title, body and commit rules."""
+        LOG.debug("Linting commit %s", commit.sha or "[SHA UNKNOWN]")
+        LOG.debug("Commit Object\n" + str(commit))
+
+        # Ensure the Deprecation class has a reference to the config currently being used
+        Deprecation.config = self.config
+
+        # Apply config rules
+        for rule in self.configuration_rules:
+            rule.apply(self.config, commit)
+
+        # Skip linting if this is a special commit type that is configured to be ignored
+        ignore_commit_types = ["merge", "squash", "fixup", "fixup_amend", "revert"]
+        for commit_type in ignore_commit_types:
+            if getattr(commit, f"is_{commit_type}_commit") and getattr(self.config, f"ignore_{commit_type}_commits"):
+                return []
+
+        violations = []
+        # determine violations by applying all rules
+        violations.extend(self._apply_line_rules([commit.message.title], commit, self.title_line_rules, 1))
+        violations.extend(self._apply_line_rules(commit.message.body, commit, self.body_line_rules, 2))
+        violations.extend(self._apply_commit_rules(self.commit_rules, commit))
+
+        # Sort violations by line number and rule_id. If there's no line nr specified (=common certain commit rules),
+        # we replace None with -1 so that it always get's placed first. Note that we need this to do this to support
+        # python 3, as None is not allowed in a list that is being sorted.
+        violations.sort(key=lambda v: (-1 if v.line_nr is None else v.line_nr, v.rule_id))
+        return violations
+
+    def print_violations(self, violations):
+        """Print a given set of violations to the standard error output"""
+        for v in violations:
+            line_nr = v.line_nr if v.line_nr else "-"
+            self.display.e(f"{line_nr}: {v.rule_id}", exact=True)
+            self.display.ee(f"{line_nr}: {v.rule_id} {v.message}", exact=True)
+            if v.content:
+                self.display.eee(f'{line_nr}: {v.rule_id} {v.message}: "{v.content}"', exact=True)
+            else:
+                self.display.eee(f"{line_nr}: {v.rule_id} {v.message}", exact=True)
diff --git a/gitlint-core/gitlint/options.py b/gitlint-core/gitlint/options.py
new file mode 100644
index 0000000..ff7d9f1
--- /dev/null
+++ b/gitlint-core/gitlint/options.py
@@ -0,0 +1,146 @@
+import os
+import re
+from abc import abstractmethod
+
+from gitlint.exception import GitlintError
+
+
+def allow_none(func):
+    """Decorator that sets option value to None if the passed value is None, otherwise calls the regular set method"""
+
+    def wrapped(obj, value):
+        if value is None:
+            obj.value = None
+        else:
+            func(obj, value)
+
+    return wrapped
+
+
+class RuleOptionError(GitlintError):
+    pass
+
+
+class RuleOption:
+    """Base class representing a configurable part (i.e. option) of a rule (e.g. the max-length of the title-max-line
+    rule).
+    This class should not be used directly. Instead, use on the derived classes like StrOption, IntOption to set
+    options of a particular type like int, str, etc.
+    """
+
+    def __init__(self, name, value, description):
+        self.name = name
+        self.description = description
+        self.value = None
+        self.set(value)
+
+    @abstractmethod
+    def set(self, value):
+        """Validates and sets the option's value"""
+
+    def __str__(self):
+        return f"({self.name}: {self.value} ({self.description}))"
+
+    def __eq__(self, other):
+        return self.name == other.name and self.description == other.description and self.value == other.value
+
+
+class StrOption(RuleOption):
+    @allow_none
+    def set(self, value):
+        self.value = str(value)
+
+
+class IntOption(RuleOption):
+    def __init__(self, name, value, description, allow_negative=False):
+        self.allow_negative = allow_negative
+        super().__init__(name, value, description)
+
+    def _raise_exception(self, value):
+        if self.allow_negative:
+            error_msg = f"Option '{self.name}' must be an integer (current value: '{value}')"
+        else:
+            error_msg = f"Option '{self.name}' must be a positive integer (current value: '{value}')"
+        raise RuleOptionError(error_msg)
+
+    @allow_none
+    def set(self, value):
+        try:
+            self.value = int(value)
+        except ValueError:
+            self._raise_exception(value)
+
+        if not self.allow_negative and self.value < 0:
+            self._raise_exception(value)
+
+
+class BoolOption(RuleOption):
+    # explicit choice to not annotate with @allow_none: Booleans must be False or True, they cannot be unset.
+    def set(self, value):
+        value = str(value).strip().lower()
+        if value not in ["true", "false"]:
+            raise RuleOptionError(f"Option '{self.name}' must be either 'true' or 'false'")
+        self.value = value == "true"
+
+
+class ListOption(RuleOption):
+    """Option that is either a given list or a comma-separated string that can be split into a list when being set."""
+
+    @allow_none
+    def set(self, value):
+        if isinstance(value, list):
+            the_list = value
+        else:
+            the_list = str(value).split(",")
+
+        self.value = [str(item.strip()) for item in the_list if item.strip() != ""]
+
+
+class PathOption(RuleOption):
+    """Option that accepts either a directory or both a directory and a file."""
+
+    def __init__(self, name, value, description, type="dir"):
+        self.type = type
+        super().__init__(name, value, description)
+
+    @allow_none
+    def set(self, value):
+        value = str(value)
+
+        error_msg = ""
+
+        if self.type == "dir":
+            if not os.path.isdir(value):
+                error_msg = f"Option {self.name} must be an existing directory (current value: '{value}')"
+        elif self.type == "file":
+            if not os.path.isfile(value):
+                error_msg = f"Option {self.name} must be an existing file (current value: '{value}')"
+        elif self.type == "both":
+            if not os.path.isdir(value) and not os.path.isfile(value):
+                error_msg = (
+                    f"Option {self.name} must be either an existing directory or file (current value: '{value}')"
+                )
+        else:
+            error_msg = f"Option {self.name} type must be one of: 'file', 'dir', 'both' (current: '{self.type}')"
+
+        if error_msg:
+            raise RuleOptionError(error_msg)
+
+        self.value = os.path.realpath(value)
+
+
+class RegexOption(RuleOption):
+    @allow_none
+    def set(self, value):
+        try:
+            self.value = re.compile(value, re.UNICODE)
+        except (re.error, TypeError) as exc:
+            raise RuleOptionError(f"Invalid regular expression: '{exc}'") from exc
+
+    def __deepcopy__(self, _):
+        # copy.deepcopy() - used in rules.py - doesn't support copying regex objects prior to Python 3.7
+        # To work around this, we have to implement this __deepcopy__ magic method
+        # Relevant SO thread:
+        # https://stackoverflow.com/questions/6279305/typeerror-cannot-deepcopy-this-pattern-object
+        value = None if self.value is None else self.value.pattern
+        return RegexOption(self.name, value, self.description)
diff --git a/gitlint-core/gitlint/rule_finder.py b/gitlint-core/gitlint/rule_finder.py
new file mode 100644
index 0000000..810faa9
--- /dev/null
+++ b/gitlint-core/gitlint/rule_finder.py
@@ -0,0 +1,155 @@
+import fnmatch
+import importlib
+import inspect
+import os
+import sys
+
+from gitlint import options, rules
+
+
+def find_rule_classes(extra_path):
+    """
+    Searches a given directory or python module for rule classes. This is done by
+    adding the directory path to the python path, importing the modules and then finding
+    any Rule class in those modules.
+
+    :param extra_path: absolute directory or file path to search for rule classes
+    :return: The list of rule classes that are found in the given directory or module
+    """
+
+    files = []
+    modules = []
+
+    if os.path.isfile(extra_path):
+        files = [os.path.basename(extra_path)]
+        directory = os.path.dirname(extra_path)
+    elif os.path.isdir(extra_path):
+        files = os.listdir(extra_path)
+        directory = extra_path
+    else:
+        raise rules.UserRuleError(f"Invalid extra-path: {extra_path}")
+
+    # Filter out files that are not python modules
+    for filename in files:
+        if fnmatch.fnmatch(filename, "*.py"):
+            # We have to treat __init__ files a bit special: add the parent dir instead of the filename, and also
+            # add their parent dir to the sys.path (this fixes import issues with pypy2).
+            if filename == "__init__.py":
+                modules.append(os.path.basename(directory))
+                sys.path.append(os.path.dirname(directory))
+            else:
+                modules.append(os.path.splitext(filename)[0])
+
+    # No need to continue if there are no modules specified
+    if not modules:
+        return []
+
+    # Append the extra rules path to python path so that we can import them
+    sys.path.append(directory)
+
+    # Find all the rule classes in the found python files
+    rule_classes = []
+    for module in modules:
+        # Import the module
+        try:
+            importlib.import_module(module)
+
+        except Exception as e:
+            raise rules.UserRuleError(f"Error while importing extra-path module '{module}': {e}") from e
+
+        # Find all rule classes in the module. We do this my inspecting all members of the module and checking
+        # 1) is it a class, if not, skip
+        # 2) is the parent path the current module. If not, we are dealing with an imported class, skip
+        # 3) is it a subclass of rule
+        rule_classes.extend(
+            [
+                clazz
+                for _, clazz in inspect.getmembers(sys.modules[module])
+                if inspect.isclass(clazz)  # check isclass to ensure clazz.__module__ exists
+                and clazz.__module__ == module  # ignore imported classes
+                and (issubclass(clazz, (rules.LineRule, rules.CommitRule, rules.ConfigurationRule)))
+            ]
+        )
+
+        # validate that the rule classes are valid user-defined rules
+        for rule_class in rule_classes:
+            assert_valid_rule_class(rule_class)
+
+    return rule_classes
+
+
+def assert_valid_rule_class(clazz, rule_type="User-defined"):  # noqa: PLR0912 (too many branches)
+    """
+    Asserts that a given rule clazz is valid by checking a number of its properties:
+     - Rules must extend from  LineRule, CommitRule or ConfigurationRule
+     - Rule classes must have id and name string attributes.
+       The options_spec is optional, but if set, it must be a list of gitlint Options.
+     - Rule classes must have a validate method. In case of a CommitRule, validate must take a single commit parameter.
+       In case of LineRule, validate must take line and commit as first and second parameters.
+     - LineRule classes must have a target class attributes that is set to either
+    - ConfigurationRule classes must have an apply method that take `config` and `commit` as parameters.
+       CommitMessageTitle or CommitMessageBody.
+     - Rule id's cannot start with R, T, B, M or I as these rule ids are reserved for gitlint itself.
+    """
+
+    # Rules must extend from LineRule, CommitRule or ConfigurationRule
+    if not issubclass(clazz, (rules.LineRule, rules.CommitRule, rules.ConfigurationRule)):
+        msg = (
+            f"{rule_type} rule class '{clazz.__name__}' "
+            f"must extend from {rules.CommitRule.__module__}.{rules.LineRule.__name__}, "
+            f"{rules.CommitRule.__module__}.{rules.CommitRule.__name__} or "
+            f"{rules.CommitRule.__module__}.{rules.ConfigurationRule.__name__}"
+        )
+        raise rules.UserRuleError(msg)
+
+    # Rules must have an id attribute
+    if not hasattr(clazz, "id") or clazz.id is None or not clazz.id:
+        raise rules.UserRuleError(f"{rule_type} rule class '{clazz.__name__}' must have an 'id' attribute")
+
+    # Rule id's cannot start with gitlint reserved letters
+    if clazz.id[0].upper() in ["R", "T", "B", "M", "I"]:
+        msg = f"The id '{clazz.id[0]}' of '{clazz.__name__}' is invalid. Gitlint reserves ids starting with R,T,B,M,I"
+        raise rules.UserRuleError(msg)
+
+    # Rules must have a name attribute
+    if not hasattr(clazz, "name") or clazz.name is None or not clazz.name:
+        raise rules.UserRuleError(f"{rule_type} rule class '{clazz.__name__}' must have a 'name' attribute")
+
+    # if set, options_spec must be a list of RuleOption
+    if not isinstance(clazz.options_spec, list):
+        msg = (
+            f"The options_spec attribute of {rule_type.lower()} rule class '{clazz.__name__}' "
+            f"must be a list of {options.RuleOption.__module__}.{options.RuleOption.__name__}"
+        )
+        raise rules.UserRuleError(msg)
+
+    # check that all items in options_spec are actual gitlint options
+    for option in clazz.options_spec:
+        if not isinstance(option, options.RuleOption):
+            msg = (
+                f"The options_spec attribute of {rule_type.lower()} rule class '{clazz.__name__}' "
+                f"must be a list of {options.RuleOption.__module__}.{options.RuleOption.__name__}"
+            )
+            raise rules.UserRuleError(msg)
+
+    # Line/Commit rules must have a `validate` method
+    # We use isroutine() as it's both python 2 and 3 compatible. Details: http://stackoverflow.com/a/17019998/381010
+    if issubclass(clazz, (rules.LineRule, rules.CommitRule)):
+        if not hasattr(clazz, "validate") or not inspect.isroutine(clazz.validate):
+            raise rules.UserRuleError(f"{rule_type} rule class '{clazz.__name__}' must have a 'validate' method")
+
+    # Configuration rules must have an `apply` method
+    elif issubclass(clazz, rules.ConfigurationRule):  # noqa: SIM102
+        if not hasattr(clazz, "apply") or not inspect.isroutine(clazz.apply):
+            msg = f"{rule_type} Configuration rule class '{clazz.__name__}' must have an 'apply' method"
+            raise rules.UserRuleError(msg)
+
+    # LineRules must have a valid target: rules.CommitMessageTitle or rules.CommitMessageBody
+    if issubclass(clazz, rules.LineRule):  # noqa: SIM102
+        if clazz.target not in [rules.CommitMessageTitle, rules.CommitMessageBody]:
+            msg = (
+                f"The target attribute of the {rule_type.lower()} LineRule class '{clazz.__name__}' "
+                f"must be either {rules.CommitMessageTitle.__module__}.{rules.CommitMessageTitle.__name__} "
+                f"or {rules.CommitMessageTitle.__module__}.{rules.CommitMessageBody.__name__}"
+            )
+            raise rules.UserRuleError(msg)
diff --git a/gitlint-core/gitlint/rules.py b/gitlint-core/gitlint/rules.py
new file mode 100644
index 0000000..ca4a05b
--- /dev/null
+++ b/gitlint-core/gitlint/rules.py
@@ -0,0 +1,485 @@
+import copy
+import logging
+import re
+
+from gitlint.deprecation import Deprecation
+from gitlint.exception import GitlintError
+from gitlint.options import BoolOption, IntOption, ListOption, RegexOption, StrOption
+
+
+class Rule:
+    """Class representing gitlint rules."""
+
+    options_spec = []
+    id = None
+    name = None
+    target = None
+    _log = None
+    _log_deprecated_regex_style_search = None
+
+    def __init__(self, opts=None):
+        if not opts:
+            opts = {}
+        self.options = {}
+        for op_spec in self.options_spec:
+            self.options[op_spec.name] = copy.deepcopy(op_spec)
+            actual_option = opts.get(op_spec.name)
+            if actual_option is not None:
+                self.options[op_spec.name].set(actual_option)
+
+    @property
+    def log(self):
+        if not self._log:
+            self._log = logging.getLogger(__name__)
+            logging.basicConfig()
+        return self._log
+
+    def __eq__(self, other):
+        return (
+            self.id == other.id
+            and self.name == other.name
+            and self.options == other.options
+            and self.target == other.target
+        )
+
+    def __str__(self):
+        return f"{self.id} {self.name}"  # pragma: no cover
+
+
+class ConfigurationRule(Rule):
+    """Class representing rules that can dynamically change the configuration of gitlint during runtime."""
+
+
+class CommitRule(Rule):
+    """Class representing rules that act on an entire commit at once"""
+
+
+class LineRule(Rule):
+    """Class representing rules that act on a line by line basis"""
+
+
+class LineRuleTarget:
+    """Base class for LineRule targets. A LineRuleTarget specifies where a given rule will be applied
+    (e.g. commit message title, commit message body).
+    Each LineRule MUST have a target specified."""
+
+
+class CommitMessageTitle(LineRuleTarget):
+    """Target class used for rules that apply to a commit message title"""
+
+
+class CommitMessageBody(LineRuleTarget):
+    """Target class used for rules that apply to a commit message body"""
+
+
+class RuleViolation:
+    """Class representing a violation of a rule. I.e.: When a rule is broken, the rule will instantiate this class
+    to indicate how and where the rule was broken."""
+
+    def __init__(self, rule_id, message, content=None, line_nr=None):
+        self.rule_id = rule_id
+        self.line_nr = line_nr
+        self.message = message
+        self.content = content
+
+    def __eq__(self, other):
+        equal = self.rule_id == other.rule_id and self.message == other.message
+        equal = equal and self.content == other.content and self.line_nr == other.line_nr
+        return equal
+
+    def __str__(self):
+        return f'{self.line_nr}: {self.rule_id} {self.message}: "{self.content}"'
+
+
+class UserRuleError(GitlintError):
+    """Error used to indicate that an error occurred while trying to load a user rule"""
+
+
+class MaxLineLength(LineRule):
+    name = "max-line-length"
+    id = "R1"
+    options_spec = [IntOption("line-length", 80, "Max line length")]
+    violation_message = "Line exceeds max length ({0}>{1})"
+
+    def validate(self, line, _commit):
+        max_length = self.options["line-length"].value
+        if len(line) > max_length:
+            return [RuleViolation(self.id, self.violation_message.format(len(line), max_length), line)]
+
+
+class TrailingWhiteSpace(LineRule):
+    name = "trailing-whitespace"
+    id = "R2"
+    violation_message = "Line has trailing whitespace"
+    pattern = re.compile(r"\s$", re.UNICODE)
+
+    def validate(self, line, _commit):
+        if self.pattern.search(line):
+            return [RuleViolation(self.id, self.violation_message, line)]
+
+
+class HardTab(LineRule):
+    name = "hard-tab"
+    id = "R3"
+    violation_message = "Line contains hard tab characters (\\t)"
+
+    def validate(self, line, _commit):
+        if "\t" in line:
+            return [RuleViolation(self.id, self.violation_message, line)]
+
+
+class LineMustNotContainWord(LineRule):
+    """Violation if a line contains one of a list of words (NOTE: using a word in the list inside another word is not
+    a violation, e.g: WIPING is not a violation if 'WIP' is a word that is not allowed.)"""
+
+    name = "line-must-not-contain"
+    id = "R5"
+    options_spec = [ListOption("words", [], "Comma separated list of words that should not be found")]
+    violation_message = "Line contains {0}"
+
+    def validate(self, line, _commit):
+        strings = self.options["words"].value
+        violations = []
+        for string in strings:
+            regex = re.compile(rf"\b{string.lower()}\b", re.IGNORECASE | re.UNICODE)
+            match = regex.search(line.lower())
+            if match:
+                violations.append(RuleViolation(self.id, self.violation_message.format(string), line))
+        return violations if violations else None
+
+
+class LeadingWhiteSpace(LineRule):
+    name = "leading-whitespace"
+    id = "R6"
+    violation_message = "Line has leading whitespace"
+
+    def validate(self, line, _commit):
+        pattern = re.compile(r"^\s", re.UNICODE)
+        if pattern.search(line):
+            return [RuleViolation(self.id, self.violation_message, line)]
+
+
+class TitleMaxLength(MaxLineLength):
+    name = "title-max-length"
+    id = "T1"
+    target = CommitMessageTitle
+    options_spec = [IntOption("line-length", 72, "Max line length")]
+    violation_message = "Title exceeds max length ({0}>{1})"
+
+
+class TitleTrailingWhitespace(TrailingWhiteSpace):
+    name = "title-trailing-whitespace"
+    id = "T2"
+    target = CommitMessageTitle
+    violation_message = "Title has trailing whitespace"
+
+
+class TitleTrailingPunctuation(LineRule):
+    name = "title-trailing-punctuation"
+    id = "T3"
+    target = CommitMessageTitle
+
+    def validate(self, title, _commit):
+        punctuation_marks = "?:!.,;"
+        for punctuation_mark in punctuation_marks:
+            if title.endswith(punctuation_mark):
+                return [RuleViolation(self.id, f"Title has trailing punctuation ({punctuation_mark})", title)]
+
+
+class TitleHardTab(HardTab):
+    name = "title-hard-tab"
+    id = "T4"
+    target = CommitMessageTitle
+    violation_message = "Title contains hard tab characters (\\t)"
+
+
+class TitleMustNotContainWord(LineMustNotContainWord):
+    name = "title-must-not-contain-word"
+    id = "T5"
+    target = CommitMessageTitle
+    options_spec = [ListOption("words", ["WIP"], "Must not contain word")]
+    violation_message = "Title contains the word '{0}' (case-insensitive)"
+
+
+class TitleLeadingWhitespace(LeadingWhiteSpace):
+    name = "title-leading-whitespace"
+    id = "T6"
+    target = CommitMessageTitle
+    violation_message = "Title has leading whitespace"
+
+
+class TitleRegexMatches(LineRule):
+    name = "title-match-regex"
+    id = "T7"
+    target = CommitMessageTitle
+    options_spec = [RegexOption("regex", None, "Regex the title should match")]
+
+    def validate(self, title, _commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        if not self.options["regex"].value.search(title):
+            violation_msg = f"Title does not match regex ({self.options['regex'].value.pattern})"
+            return [RuleViolation(self.id, violation_msg, title)]
+
+
+class TitleMinLength(LineRule):
+    name = "title-min-length"
+    id = "T8"
+    target = CommitMessageTitle
+    options_spec = [IntOption("min-length", 5, "Minimum required title length")]
+
+    def validate(self, title, _commit):
+        min_length = self.options["min-length"].value
+        actual_length = len(title)
+        if actual_length < min_length:
+            violation_message = f"Title is too short ({actual_length}<{min_length})"
+            return [RuleViolation(self.id, violation_message, title, 1)]
+
+
+class BodyMaxLineLength(MaxLineLength):
+    name = "body-max-line-length"
+    id = "B1"
+    target = CommitMessageBody
+
+
+class BodyTrailingWhitespace(TrailingWhiteSpace):
+    name = "body-trailing-whitespace"
+    id = "B2"
+    target = CommitMessageBody
+
+
+class BodyHardTab(HardTab):
+    name = "body-hard-tab"
+    id = "B3"
+    target = CommitMessageBody
+
+
+class BodyFirstLineEmpty(CommitRule):
+    name = "body-first-line-empty"
+    id = "B4"
+
+    def validate(self, commit):
+        if len(commit.message.body) >= 1:
+            first_line = commit.message.body[0]
+            if first_line != "":
+                return [RuleViolation(self.id, "Second line is not empty", first_line, 2)]
+
+
+class BodyMinLength(CommitRule):
+    name = "body-min-length"
+    id = "B5"
+    options_spec = [IntOption("min-length", 20, "Minimum body length")]
+
+    def validate(self, commit):
+        min_length = self.options["min-length"].value
+        body_message_no_newline = "".join([line for line in commit.message.body if line is not None])
+        actual_length = len(body_message_no_newline)
+        if 0 < actual_length < min_length:
+            violation_message = f"Body message is too short ({actual_length}<{min_length})"
+            return [RuleViolation(self.id, violation_message, body_message_no_newline, 3)]
+
+
+class BodyMissing(CommitRule):
+    name = "body-is-missing"
+    id = "B6"
+    options_spec = [BoolOption("ignore-merge-commits", True, "Ignore merge commits")]
+
+    def validate(self, commit):
+        # ignore merges when option tells us to, which may have no body
+        if self.options["ignore-merge-commits"].value and commit.is_merge_commit:
+            return
+        if len(commit.message.body) < 2 or not "".join(commit.message.body).strip():  # noqa: PLR2004 (Magic value)
+            return [RuleViolation(self.id, "Body message is missing", None, 3)]
+
+
+class BodyChangedFileMention(CommitRule):
+    name = "body-changed-file-mention"
+    id = "B7"
+    options_spec = [ListOption("files", [], "Files that need to be mentioned")]
+
+    def validate(self, commit):
+        violations = []
+        for needs_mentioned_file in self.options["files"].value:
+            # if a file that we need to look out for is actually changed, then check whether it occurs
+            # in the commit msg body
+            if needs_mentioned_file in commit.changed_files:  # noqa: SIM102
+                if needs_mentioned_file not in " ".join(commit.message.body):
+                    violation_message = f"Body does not mention changed file '{needs_mentioned_file}'"
+                    violations.append(RuleViolation(self.id, violation_message, None, len(commit.message.body) + 1))
+        return violations if violations else None
+
+
+class BodyRegexMatches(CommitRule):
+    name = "body-match-regex"
+    id = "B8"
+    options_spec = [RegexOption("regex", None, "Regex the body should match")]
+
+    def validate(self, commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        # We intentionally ignore the first line in the body as that's the empty line after the title,
+        # which most users are not going to expect to be part of the body when matching a regex.
+        # If this causes contention, we can always introduce an option to change the behavior in a backward-
+        # compatible way.
+        body_lines = commit.message.body[1:] if len(commit.message.body) > 1 else []
+
+        # Similarly, the last line is often empty, this has to do with how git returns commit messages
+        # User's won't expect this, so prune it off by default
+        if body_lines and body_lines[-1] == "":
+            body_lines.pop()
+
+        full_body = "\n".join(body_lines)
+
+        if not self.options["regex"].value.search(full_body):
+            violation_msg = f"Body does not match regex ({self.options['regex'].value.pattern})"
+            return [RuleViolation(self.id, violation_msg, None, len(commit.message.body) + 1)]
+
+
+class AuthorValidEmail(CommitRule):
+    name = "author-valid-email"
+    id = "M1"
+    DEFAULT_AUTHOR_VALID_EMAIL_REGEX = r"^[^@ ]+@[^@ ]+\.[^@ ]+"
+    options_spec = [
+        RegexOption("regex", DEFAULT_AUTHOR_VALID_EMAIL_REGEX, "Regex that author email address should match")
+    ]
+
+    def validate(self, commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        # We're replacing regex match with search semantics, see https://github.com/jorisroovers/gitlint/issues/254
+        # In case the user is using the default regex, we can silently change to using search
+        # If not, it depends on config (handled by Deprecation class)
+        if self.options["regex"].value.pattern == self.DEFAULT_AUTHOR_VALID_EMAIL_REGEX:
+            regex_method = self.options["regex"].value.search
+        else:
+            regex_method = Deprecation.get_regex_method(self, self.options["regex"])
+
+        if commit.author_email and not regex_method(commit.author_email):
+            return [RuleViolation(self.id, "Author email for commit is invalid", commit.author_email)]
+
+
+class IgnoreByTitle(ConfigurationRule):
+    name = "ignore-by-title"
+    id = "I1"
+    options_spec = [
+        RegexOption("regex", None, "Regex matching the titles of commits this rule should apply to"),
+        StrOption("ignore", "all", "Comma-separated list of rules to ignore"),
+    ]
+
+    def apply(self, config, commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        # We're replacing regex match with search semantics, see https://github.com/jorisroovers/gitlint/issues/254
+        regex_method = Deprecation.get_regex_method(self, self.options["regex"])
+
+        if regex_method(commit.message.title):
+            config.ignore = self.options["ignore"].value
+
+            message = (
+                f"Commit title '{commit.message.title}' matches the regex "
+                f"'{self.options['regex'].value.pattern}', ignoring rules: {self.options['ignore'].value}"
+            )
+
+            self.log.debug("Ignoring commit because of rule '%s': %s", self.id, message)
+
+
+class IgnoreByBody(ConfigurationRule):
+    name = "ignore-by-body"
+    id = "I2"
+    options_spec = [
+        RegexOption("regex", None, "Regex matching lines of the body of commits this rule should apply to"),
+        StrOption("ignore", "all", "Comma-separated list of rules to ignore"),
+    ]
+
+    def apply(self, config, commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        # We're replacing regex match with search semantics, see https://github.com/jorisroovers/gitlint/issues/254
+        regex_method = Deprecation.get_regex_method(self, self.options["regex"])
+
+        for line in commit.message.body:
+            if regex_method(line):
+                config.ignore = self.options["ignore"].value
+
+                message = (
+                    f"Commit message line '{line}' matches the regex '{self.options['regex'].value.pattern}',"
+                    f" ignoring rules: {self.options['ignore'].value}"
+                )
+
+                self.log.debug("Ignoring commit because of rule '%s': %s", self.id, message)
+                # No need to check other lines if we found a match
+                return
+
+
+class IgnoreBodyLines(ConfigurationRule):
+    name = "ignore-body-lines"
+    id = "I3"
+    options_spec = [RegexOption("regex", None, "Regex matching lines of the body that should be ignored")]
+
+    def apply(self, _, commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        # We're replacing regex match with search semantics, see https://github.com/jorisroovers/gitlint/issues/254
+        regex_method = Deprecation.get_regex_method(self, self.options["regex"])
+
+        new_body = []
+        for line in commit.message.body:
+            if regex_method(line):
+                debug_msg = "Ignoring line '%s' because it matches '%s'"
+                self.log.debug(debug_msg, line, self.options["regex"].value.pattern)
+            else:
+                new_body.append(line)
+
+        commit.message.body = new_body
+        commit.message.full = "\n".join([commit.message.title, *new_body])
+
+
+class IgnoreByAuthorName(ConfigurationRule):
+    name = "ignore-by-author-name"
+    id = "I4"
+    options_spec = [
+        RegexOption("regex", None, "Regex matching the author name of commits this rule should apply to"),
+        StrOption("ignore", "all", "Comma-separated list of rules to ignore"),
+    ]
+
+    def apply(self, config, commit):
+        # If no regex is specified, immediately return
+        if not self.options["regex"].value:
+            return
+
+        # If commit.author_name is not available, log warning and return
+        if commit.author_name is None:
+            warning_msg = (
+                "%s - %s: skipping - commit.author_name unknown. "
+                "Suggested fix: Use the --staged flag (or set general.staged=True in .gitlint). "
+                "More details: https://jorisroovers.com/gitlint/configuration/#staged"
+            )
+
+            self.log.warning(warning_msg, self.name, self.id)
+            return
+
+        regex_method = Deprecation.get_regex_method(self, self.options["regex"])
+
+        if regex_method(commit.author_name):
+            config.ignore = self.options["ignore"].value
+
+            message = (
+                f"Commit Author Name '{commit.author_name}' matches the regex "
+                f"'{self.options['regex'].value.pattern}', ignoring rules: {self.options['ignore'].value}"
+            )
+
+            self.log.debug("Ignoring commit because of rule '%s': %s", self.id, message)
+            # No need to check other lines if we found a match
+            return
diff --git a/gitlint-core/gitlint/shell.py b/gitlint-core/gitlint/shell.py
new file mode 100644
index 0000000..fddece0
--- /dev/null
+++ b/gitlint-core/gitlint/shell.py
@@ -0,0 +1,78 @@
+"""
+This module implements a shim for the 'sh' library, mainly for use on Windows (sh is not supported on Windows).
+We might consider removing the 'sh' dependency altogether in the future, but 'sh' does provide a few
+capabilities wrt dealing with more edge-case environments on *nix systems that are useful.
+"""
+
+import subprocess
+
+from gitlint.utils import TERMINAL_ENCODING, USE_SH_LIB
+
+
+def shell(cmd):
+    """Convenience function that opens a given command in a shell. Does not use 'sh' library."""
+    with subprocess.Popen(cmd, shell=True) as p:
+        p.communicate()
+
+
+if USE_SH_LIB:
+    # import exceptions separately, this makes it a little easier to mock them out in the unit tests
+    from sh import (
+        CommandNotFound,
+        ErrorReturnCode,
+        git,
+    )
+else:
+
+    class CommandNotFound(Exception):
+        """Exception indicating a command was not found during execution"""
+
+    class ShResult:
+        """Result wrapper class. We use this to more easily migrate from using https://amoffat.github.io/sh/ to using
+        the builtin subprocess module"""
+
+        def __init__(self, full_cmd, stdout, stderr="", exitcode=0):
+            self.full_cmd = full_cmd
+            self.stdout = stdout
+            self.stderr = stderr
+            self.exit_code = exitcode
+
+        def __str__(self):
+            return self.stdout
+
+    class ErrorReturnCode(ShResult, Exception):
+        """ShResult subclass for unexpected results (acts as an exception)."""
+
+    def git(*command_parts, **kwargs):
+        """Git shell wrapper.
+        Implemented as separate function here, so we can do a 'sh' style imports:
+        `from shell import git`
+        """
+        args = ["git", *list(command_parts)]
+        return _exec(*args, **kwargs)
+
+    def _exec(*args, **kwargs):
+        pipe = subprocess.PIPE
+        popen_kwargs = {"stdout": pipe, "stderr": pipe, "shell": kwargs.get("_tty_out", False)}
+        if "_cwd" in kwargs:
+            popen_kwargs["cwd"] = kwargs["_cwd"]
+
+        try:
+            with subprocess.Popen(args, **popen_kwargs) as p:
+                result = p.communicate()
+        except FileNotFoundError as e:
+            raise CommandNotFound from e
+
+        exit_code = p.returncode
+        stdout = result[0].decode(TERMINAL_ENCODING)
+        stderr = result[1]  # 'sh' does not decode the stderr bytes to unicode
+        full_cmd = "" if args is None else " ".join(args)
+
+        # If not _ok_code is specified, then only a 0 exit code is allowed
+        ok_exit_codes = kwargs.get("_ok_code", [0])
+
+        if exit_code in ok_exit_codes:
+            return ShResult(full_cmd, stdout, stderr, exit_code)
+
+        # Unexpected error code => raise ErrorReturnCode
+        raise ErrorReturnCode(full_cmd, stdout, stderr, p.returncode)
diff --git a/gitlint-core/gitlint/tests/__init__.py b/gitlint-core/gitlint/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/gitlint-core/gitlint/tests/base.py b/gitlint-core/gitlint/tests/base.py
new file mode 100644
index 0000000..3899a5f
--- /dev/null
+++ b/gitlint-core/gitlint/tests/base.py
@@ -0,0 +1,227 @@
+import contextlib
+import copy
+import logging
+import os
+import re
+import shutil
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+from gitlint.config import LintConfig
+from gitlint.deprecation import LOG as DEPRECATION_LOG
+from gitlint.deprecation import Deprecation
+from gitlint.git import GitChangedFileStats, GitContext
+from gitlint.utils import FILE_ENCODING, LOG_FORMAT
+
+EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING = (
+    "WARNING: gitlint.deprecated.regex_style_search {0} - {1}: gitlint will be switching from using "
+    "Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. "
+    "Please review your {1}.regex option accordingly. "
+    "To remove this warning, set general.regex-style-search=True. More details: "
+    "https://jorisroovers.github.io/gitlint/configuration/#regex-style-search"
+)
+
+
+class BaseTestCase(unittest.TestCase):
+    """Base class of which all gitlint unit test classes are derived. Provides a number of convenience methods."""
+
+    # In case of assert failures, print the full error message
+    maxDiff = None
+
+    # Working directory in which tests in this class are executed
+    working_dir = None
+    # Originally working dir when the test was started
+    original_working_dir = None
+
+    SAMPLES_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "samples")
+    EXPECTED_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "expected")
+    GITLINT_USE_SH_LIB = os.environ.get("GITLINT_USE_SH_LIB", "[NOT SET]")
+
+    @classmethod
+    def setUpClass(cls):
+        # Run tests a temporary directory to shield them from any local git config
+        cls.original_working_dir = os.getcwd()
+        cls.working_dir = tempfile.mkdtemp()
+        os.chdir(cls.working_dir)
+
+    @classmethod
+    def tearDownClass(cls):
+        # Go back to original working dir and remove our temp working dir
+        os.chdir(cls.original_working_dir)
+        shutil.rmtree(cls.working_dir)
+
+    def setUp(self):
+        self.logcapture = LogCapture()
+        self.logcapture.setFormatter(logging.Formatter(LOG_FORMAT))
+        logging.getLogger("gitlint").setLevel(logging.DEBUG)
+        logging.getLogger("gitlint").handlers = [self.logcapture]
+        DEPRECATION_LOG.handlers = [self.logcapture]
+
+        # Make sure we don't propagate anything to child loggers, we need to do this explicitly here
+        # because if you run a specific test file like test_lint.py, we won't be calling the setupLogging() method
+        # in gitlint.cli that normally takes care of this
+        # Example test where this matters (for DEPRECATION_LOG):
+        # gitlint-core/gitlint/tests/rules/test_configuration_rules.py::ConfigurationRuleTests::test_ignore_by_title
+        logging.getLogger("gitlint").propagate = False
+        DEPRECATION_LOG.propagate = False
+
+        # Make sure Deprecation has a clean config set at the start of each test.
+        # Tests that want to specifically test deprecation should override this.
+        Deprecation.config = LintConfig()
+        # Normally Deprecation only logs messages once per process.
+        # For tests we want to log every time, so we reset the warning_msgs set per test.
+        Deprecation.warning_msgs = set()
+
+    @staticmethod
+    @contextlib.contextmanager
+    def tempdir():
+        tmpdir = tempfile.mkdtemp()
+        try:
+            yield tmpdir
+        finally:
+            shutil.rmtree(tmpdir)
+
+    @staticmethod
+    def get_sample_path(filename=""):
+        # Don't join up empty files names because this will add a trailing slash
+        if filename == "":
+            return BaseTestCase.SAMPLES_DIR
+
+        return os.path.join(BaseTestCase.SAMPLES_DIR, filename)
+
+    @staticmethod
+    def get_sample(filename=""):
+        """Read and return the contents of a file in gitlint/tests/samples"""
+        sample_path = BaseTestCase.get_sample_path(filename)
+        return Path(sample_path).read_text(encoding=FILE_ENCODING)
+
+    @staticmethod
+    def patch_input(side_effect):
+        """Patches the built-in input() with a provided side-effect"""
+        module_path = "builtins.input"
+        patched_module = patch(module_path, side_effect=side_effect)
+        return patched_module
+
+    @staticmethod
+    def get_expected(filename="", variable_dict=None):
+        """Utility method to read an expected file from gitlint/tests/expected and return it as a string.
+        Optionally replace template variables specified by variable_dict."""
+        expected_path = os.path.join(BaseTestCase.EXPECTED_DIR, filename)
+        expected = Path(expected_path).read_text(encoding=FILE_ENCODING)
+
+        if variable_dict:
+            expected = expected.format(**variable_dict)
+        return expected
+
+    @staticmethod
+    def get_user_rules_path():
+        return os.path.join(BaseTestCase.SAMPLES_DIR, "user_rules")
+
+    @staticmethod
+    def gitcontext(commit_msg_str, changed_files=None):
+        """Utility method to easily create gitcontext objects based on a given commit msg string and an optional set of
+        changed files"""
+        with patch("gitlint.git.git_commentchar") as comment_char:
+            comment_char.return_value = "#"
+            gitcontext = GitContext.from_commit_msg(commit_msg_str)
+            commit = gitcontext.commits[-1]
+            if changed_files:
+                changed_file_stats = {filename: GitChangedFileStats(filename, 8, 3) for filename in changed_files}
+                commit.changed_files_stats = changed_file_stats
+            return gitcontext
+
+    @staticmethod
+    def gitcommit(commit_msg_str, changed_files=None, **kwargs):
+        """Utility method to easily create git commit given a commit msg string and an optional set of changed files"""
+        gitcontext = BaseTestCase.gitcontext(commit_msg_str, changed_files)
+        commit = gitcontext.commits[-1]
+        for attr, value in kwargs.items():
+            setattr(commit, attr, value)
+        return commit
+
+    def assert_logged(self, expected):
+        """Asserts that the logs match an expected string or list.
+        This method knows how to compare a passed list of log lines as well as a newline concatenated string
+        of all loglines."""
+        if isinstance(expected, list):
+            self.assertListEqual(self.logcapture.messages, expected)
+        else:
+            self.assertEqual("\n".join(self.logcapture.messages), expected)
+
+    def assert_log_contains(self, line):
+        """Asserts that a certain line is in the logs"""
+        self.assertIn(line, self.logcapture.messages)
+
+    def assertRaisesRegex(self, expected_exception, expected_regex, *args, **kwargs):
+        """Pass-through method to unittest.TestCase.assertRaisesRegex that applies re.escape() to the passed
+        `expected_regex`. This is useful to automatically escape all file paths that might be present in the regex.
+        """
+        return super().assertRaisesRegex(expected_exception, re.escape(expected_regex), *args, **kwargs)
+
+    def clearlog(self):
+        """Clears the log capture"""
+        self.logcapture.clear()
+
+    @contextlib.contextmanager
+    def assertRaisesMessage(self, expected_exception, expected_msg):
+        """Asserts an exception has occurred with a given error message"""
+        try:
+            yield
+        except expected_exception as exc:
+            exception_msg = str(exc)
+            if exception_msg != expected_msg:  # pragma: nocover
+                error = f"Right exception, wrong message:\n      got: {exception_msg}\n expected: {expected_msg}"
+                raise self.fail(error) from exc
+            # else: everything is fine, just return
+            return
+        except Exception as exc:  # pragma: nocover
+            raise self.fail(f"Expected '{expected_exception.__name__}' got '{exc.__class__.__name__}'") from exc
+
+        # No exception raised while we expected one
+        raise self.fail(
+            f"Expected to raise {expected_exception.__name__}, didn't get an exception at all"
+        )  # pragma: nocover
+
+    def object_equality_test(self, obj, attr_list, ctor_kwargs=None):
+        """Helper function to easily implement object equality tests.
+        Creates an object clone for every passed attribute and checks for (in)equality
+        of the original object with the clone based on those attributes' values.
+        This function assumes all attributes in `attr_list` can be passed to the ctor of `obj.__class__`.
+        """
+        if not ctor_kwargs:
+            ctor_kwargs = {}
+
+        attr_kwargs = {}
+        for attr in attr_list:
+            attr_kwargs[attr] = getattr(obj, attr)
+
+        # For every attr, clone the object and assert the clone and the original object are equal
+        # Then, change the current attr and assert objects are unequal
+        for attr in attr_list:
+            attr_kwargs_copy = copy.deepcopy(attr_kwargs)
+            attr_kwargs_copy.update(ctor_kwargs)
+            clone = obj.__class__(**attr_kwargs_copy)
+            self.assertEqual(obj, clone)
+
+            # Change attribute and assert objects are different (via both attribute set and ctor)
+            setattr(clone, attr, "föo")
+            self.assertNotEqual(obj, clone)
+            attr_kwargs_copy[attr] = "föo"
+
+            self.assertNotEqual(obj, obj.__class__(**attr_kwargs_copy))
+
+
+class LogCapture(logging.Handler):
+    """Mock logging handler used to capture any log messages during tests."""
+
+    def __init__(self, *args, **kwargs):
+        logging.Handler.__init__(self, *args, **kwargs)
+        self.messages = []
+
+    def emit(self, record):
+        self.messages.append(self.format(record))
+
+    def clear(self):
+        self.messages = []
diff --git a/gitlint-core/gitlint/tests/cli/test_cli.py b/gitlint-core/gitlint/tests/cli/test_cli.py
new file mode 100644
index 0000000..c006375
--- /dev/null
+++ b/gitlint-core/gitlint/tests/cli/test_cli.py
@@ -0,0 +1,736 @@
+import os
+import platform
+import sys
+from io import StringIO
+from unittest.mock import patch
+
+import arrow
+from click.testing import CliRunner
+from gitlint import __version__, cli
+from gitlint.shell import CommandNotFound
+from gitlint.tests.base import BaseTestCase
+from gitlint.utils import FILE_ENCODING, TERMINAL_ENCODING
+
+
+class CLITests(BaseTestCase):
+    USAGE_ERROR_CODE = 253
+    GIT_CONTEXT_ERROR_CODE = 254
+    CONFIG_ERROR_CODE = 255
+    GITLINT_SUCCESS_CODE = 0
+
+    def setUp(self):
+        super().setUp()
+        self.cli = CliRunner()
+
+        # Patch gitlint.cli.git_version() so that we don't have to patch it separately in every test
+        self.git_version_path = patch("gitlint.cli.git_version")
+        cli.git_version = self.git_version_path.start()
+        cli.git_version.return_value = "git version 1.2.3"
+
+    def tearDown(self):
+        self.git_version_path.stop()
+
+    @staticmethod
+    def get_system_info_dict():
+        """Returns a dict with items related to system values logged by `gitlint --debug`"""
+        return {
+            "platform": platform.platform(),
+            "python_version": sys.version,
+            "gitlint_version": __version__,
+            "GITLINT_USE_SH_LIB": BaseTestCase.GITLINT_USE_SH_LIB,
+            "target": os.path.realpath(os.getcwd()),
+            "TERMINAL_ENCODING": TERMINAL_ENCODING,
+            "FILE_ENCODING": FILE_ENCODING,
+        }
+
+    def test_version(self):
+        """Test for --version option"""
+        result = self.cli.invoke(cli.cli, ["--version"])
+        self.assertEqual(result.output.split("\n")[0], f"cli, version {__version__}")
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_lint(self, sh, _):
+        """Test for basic simple linting functionality"""
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360",
+            "test åuthor\x00test-email@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\ncommït-title\n\ncommït-body",
+            "#",  # git config --get core.commentchar
+            "1\t4\tfile1.txt\n3\t5\tpåth/to/file2.txt\n",
+            "commit-1-branch-1\ncommit-1-branch-2\n",
+        ]
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli)
+            self.assertEqual(stderr.getvalue(), '3: B5 Body message is too short (11<20): "commït-body"\n')
+            self.assertEqual(result.exit_code, 1)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_lint_multiple_commits(self, sh, _):
+        """Test for --commits option"""
+
+        # fmt: off
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360\n" +  # git rev-list <SHA>
+            "25053ccec5e28e1bb8f7551fdbb5ab213ada2401\n" +
+            "4da2656b0dadc76c7ee3fd0243a96cb64007f125\n",
+            # git log --pretty <FORMAT> <SHA>
+            "test åuthor1\x00test-email1@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            "commït-title1\n\ncommït-body1",
+            "#",                                           # git config --get core.commentchar
+            "3\t5\tcommit-1/file-1\n1\t4\tcommit-1/file-2\n",          # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor2\x00test-email3@föo.com\x002016-12-04 15:28:15 +0100\x00åbc\n"
+            "commït-title2\n\ncommït-body2",
+            "8\t3\tcommit-2/file-1\n1\t5\tcommit-2/file-2\n",          # git diff-tree
+            "commit-2-branch-1\ncommit-2-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor3\x00test-email3@föo.com\x002016-12-05 15:28:15 +0100\x00åbc\n"
+            "commït-title3\n\ncommït-body3",
+            "7\t2\tcommit-3/file-1\n1\t7\tcommit-3/file-2\n",          # git diff-tree
+            "commit-3-branch-1\ncommit-3-branch-2\n",      # git branch --contains <sha>
+        ]
+        # fmt: on
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--commits", "foo...bar"])
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_lint_multiple_commits_1"))
+            self.assertEqual(result.exit_code, 3)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_lint_multiple_commits_csv(self, sh, _):
+        """Test for --commits option"""
+
+        # fmt: off
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360\n",  # git rev-list <SHA>
+            "25053ccec5e28e1bb8f7551fdbb5ab213ada2401\n",
+            "4da2656b0dadc76c7ee3fd0243a96cb64007f125\n",
+            # git log --pretty <FORMAT> <SHA>
+            "test åuthor1\x00test-email1@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            "commït-title1\n\ncommït-body1",
+            "#",                                           # git config --get core.commentchar
+            "3\t5\tcommit-1/file-1\n1\t4\tcommit-1/file-2\n",          # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor2\x00test-email3@föo.com\x002016-12-04 15:28:15 +0100\x00åbc\n"
+            "commït-title2\n\ncommït-body2",
+            "8\t3\tcommit-2/file-1\n1\t5\tcommit-2/file-2\n",          # git diff-tree
+            "commit-2-branch-1\ncommit-2-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor3\x00test-email3@föo.com\x002016-12-05 15:28:15 +0100\x00åbc\n"
+            "commït-title3\n\ncommït-body3",
+            "7\t2\tcommit-3/file-1\n1\t7\tcommit-3/file-2\n",          # git diff-tree
+            "commit-3-branch-1\ncommit-3-branch-2\n",      # git branch --contains <sha>
+        ]
+        # fmt: on
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--commits", "6f29bf81,25053cce,4da2656b"])
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_lint_multiple_commits_csv_1"))
+            self.assertEqual(result.exit_code, 3)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_lint_multiple_commits_config(self, sh, _):
+        """Test for --commits option where some of the commits have gitlint config in the commit message"""
+
+        # fmt: off
+        # Note that the second commit title has a trailing period that is being ignored by gitlint-ignore: T3
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360\n" +  # git rev-list <SHA>
+            "25053ccec5e28e1bb8f7551fdbb5ab213ada2401\n" +
+            "4da2656b0dadc76c7ee3fd0243a96cb64007f125\n",
+            # git log --pretty <FORMAT> <SHA>
+            "test åuthor1\x00test-email1@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            "commït-title1\n\ncommït-body1",
+            "#",                                           # git config --get core.commentchar
+            "9\t4\tcommit-1/file-1\n0\t2\tcommit-1/file-2\n",          # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor2\x00test-email2@föo.com\x002016-12-04 15:28:15 +0100\x00åbc\n"
+            "commït-title2.\n\ncommït-body2\ngitlint-ignore: T3\n",
+            "3\t7\tcommit-2/file-1\n4\t6\tcommit-2/file-2\n",          # git diff-tree
+            "commit-2-branch-1\ncommit-2-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor3\x00test-email3@föo.com\x002016-12-05 15:28:15 +0100\x00åbc\n"
+            "commït-title3.\n\ncommït-body3",
+            "3\t8\tcommit-3/file-1\n1\t4\tcommit-3/file-2\n",          # git diff-tree
+            "commit-3-branch-1\ncommit-3-branch-2\n",      # git branch --contains <sha>
+        ]
+        # fmt: on
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--commits", "foo...bar"])
+            # We expect that the second commit has no failures because of 'gitlint-ignore: T3' in its commit msg body
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_lint_multiple_commits_config_1"))
+            self.assertEqual(result.exit_code, 3)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_lint_multiple_commits_configuration_rules(self, sh, _):
+        """Test for --commits option where where we have configured gitlint to ignore certain rules for certain commits"""
+
+        # fmt: off
+        # Note that the second commit
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360\n" +  # git rev-list <SHA>
+            "25053ccec5e28e1bb8f7551fdbb5ab213ada2401\n" +
+            "4da2656b0dadc76c7ee3fd0243a96cb64007f125\n",
+            # git log --pretty <FORMAT> <SHA>
+            "test åuthor1\x00test-email1@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            "commït-title1\n\ncommït-body1",
+            "#",                                           # git config --get core.commentchar
+            "5\t9\tcommit-1/file-1\n1\t4\tcommit-1/file-2\n",          # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor2\x00test-email3@föo.com\x002016-12-04 15:28:15 +0100\x00åbc\n"
+            # Normally T3 violation (trailing punctuation), but this commit is ignored because of
+            # config below
+            "commït-title2.\n\ncommït-body2\n",
+            "4\t7\tcommit-2/file-1\n1\t4\tcommit-2/file-2\n",          # git diff-tree
+            "commit-2-branch-1\ncommit-2-branch-2\n",      # git branch --contains <sha>
+                                                            # git log --pretty <FORMAT> <SHA>
+            "test åuthor3\x00test-email3@föo.com\x002016-12-05 15:28:15 +0100\x00åbc\n"
+            # Normally T1 and B5 violations, now only T1 because we're ignoring B5 in config below
+            "commït-title3.\n\ncommït-body3 foo",
+            "1\t9\tcommit-3/file-1\n3\t7\tcommit-3/file-2\n",          # git diff-tree
+            "commit-3-branch-1\ncommit-3-branch-2\n",      # git branch --contains <sha>
+        ]
+        # fmt: on
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(
+                cli.cli,
+                [
+                    "--commits",
+                    "foo...bar",
+                    "-c",
+                    "I1.regex=^commït-title2(.*)",
+                    "-c",
+                    "I2.regex=^commït-body3(.*)",
+                    "-c",
+                    "I2.ignore=B5",
+                ],
+            )
+            # We expect that the second commit has no failures because of it matching against I1.regex
+            # Because we do test for the 3th commit to return violations, this test also ensures that a unique
+            # config object is passed to each commit lint call
+            expected = (
+                "Commit 6f29bf81a8:\n"
+                '3: B5 Body message is too short (12<20): "commït-body1"\n\n'
+                "Commit 4da2656b0d:\n"
+                '1: T3 Title has trailing punctuation (.): "commït-title3."\n'
+            )
+            self.assertEqual(stderr.getvalue(), expected)
+            self.assertEqual(result.exit_code, 2)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_lint_commit(self, sh, _):
+        """Test for --commit option"""
+
+        # fmt: off
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360\n",  # git log -1 <SHA> --pretty=%H
+            # git log --pretty <FORMAT> <SHA>
+            "test åuthor1\x00test-email1@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            "WIP: commït-title1\n\ncommït-body1",
+            "#",                                           # git config --get core.commentchar
+            "4\t5\tcommit-1/file-1\n1\t4\tcommit-1/file-2\n",          # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",      # git branch --contains <sha>
+        ]
+        # fmt: on
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--commit", "foo"])
+            self.assertEqual(result.output, "")
+
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_lint_commit_1"))
+            self.assertEqual(result.exit_code, 2)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    def test_lint_commit_negative(self, _):
+        """Negative test for --commit option"""
+
+        # Try using --commit and --commits at the same time (not allowed)
+        result = self.cli.invoke(cli.cli, ["--commit", "foo", "--commits", "foo...bar"])
+        expected_output = "Error: --commit and --commits are mutually exclusive, use one or the other.\n"
+        self.assertEqual(result.output, expected_output)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tïtle \n")
+    def test_input_stream(self, _):
+        """Test for linting when a message is passed via stdin"""
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli)
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_input_stream_1"))
+            self.assertEqual(result.exit_code, 3)
+            self.assertEqual(result.output, "")
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tïtle \n")
+    def test_input_stream_debug(self, _):
+        """Test for linting when a message is passed via stdin, and debug is enabled.
+        This tests specifically that git commit meta is not fetched when not passing --staged"""
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--debug"])
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_input_stream_debug_1"))
+            self.assertEqual(result.exit_code, 3)
+            self.assertEqual(result.output, "")
+            expected_kwargs = self.get_system_info_dict()
+            expected_logs = self.get_expected("cli/test_cli/test_input_stream_debug_2", expected_kwargs)
+            self.assert_logged(expected_logs)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="Should be ignored\n")
+    @patch("gitlint.git.sh")
+    def test_lint_ignore_stdin(self, sh, stdin_data):
+        """Test for ignoring stdin when --ignore-stdin flag is enabled"""
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360",
+            "test åuthor\x00test-email@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\ncommït-title\n\ncommït-body",
+            "#",  # git config --get core.commentchar
+            "3\t12\tfile1.txt\n8\t5\tpåth/to/file2.txt\n",  # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",  # git branch --contains <sha>
+        ]
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--ignore-stdin"])
+            self.assertEqual(stderr.getvalue(), '3: B5 Body message is too short (11<20): "commït-body"\n')
+            self.assertEqual(result.exit_code, 1)
+
+        # Assert that we didn't even try to get the stdin data
+        self.assertEqual(stdin_data.call_count, 0)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tïtle \n")
+    @patch("arrow.now", return_value=arrow.get("2020-02-19T12:18:46.675182+01:00"))
+    @patch("gitlint.git.sh")
+    def test_lint_staged_stdin(self, sh, _, __):
+        """Test for ignoring stdin when --ignore-stdin flag is enabled"""
+
+        sh.git.side_effect = [
+            "#",  # git config --get core.commentchar
+            "1\t5\tcommit-1/file-1\n8\t9\tcommit-1/file-2\n",  # git diff-tree
+            "föo user\n",  # git config --get user.name
+            "föo@bar.com\n",  # git config --get user.email
+            "my-branch\n",  # git rev-parse --abbrev-ref HEAD (=current branch)
+        ]
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--debug", "--staged"])
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_lint_staged_stdin_1"))
+            self.assertEqual(result.exit_code, 3)
+            self.assertEqual(result.output, "")
+
+            expected_kwargs = self.get_system_info_dict()
+            changed_files_stats = (
+                f"  {os.path.join('commit-1', 'file-1')}: 1 additions, 5 deletions\n"
+                f"  {os.path.join('commit-1', 'file-2')}: 8 additions, 9 deletions"
+            )
+            expected_kwargs.update({"changed_files_stats": changed_files_stats})
+            expected_logs = self.get_expected("cli/test_cli/test_lint_staged_stdin_2", expected_kwargs)
+            self.assert_logged(expected_logs)
+
+    @patch("arrow.now", return_value=arrow.get("2020-02-19T12:18:46.675182+01:00"))
+    @patch("gitlint.git.sh")
+    def test_lint_staged_msg_filename(self, sh, _):
+        """Test for ignoring stdin when --ignore-stdin flag is enabled"""
+
+        # fmt: off
+        sh.git.side_effect = [
+            "#",                                         # git config --get core.commentchar
+            "3\t4\tcommit-1/file-1\n4\t7\tcommit-1/file-2\n",        # git diff-tree
+            "föo user\n",                                # git config --get user.name
+            "föo@bar.com\n",                             # git config --get user.email
+            "my-branch\n",                               # git rev-parse --abbrev-ref HEAD (=current branch)
+        ]
+        # fmt: on
+
+        with self.tempdir() as tmpdir:
+            msg_filename = os.path.join(tmpdir, "msg")
+            with open(msg_filename, "w", encoding=FILE_ENCODING) as f:
+                f.write("WIP: msg-filename tïtle\n")
+
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                result = self.cli.invoke(cli.cli, ["--debug", "--staged", "--msg-filename", msg_filename])
+                self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_lint_staged_msg_filename_1"))
+                self.assertEqual(result.exit_code, 2)
+                self.assertEqual(result.output, "")
+
+                expected_kwargs = self.get_system_info_dict()
+                changed_files_stats = (
+                    f"  {os.path.join('commit-1', 'file-1')}: 3 additions, 4 deletions\n"
+                    f"  {os.path.join('commit-1', 'file-2')}: 4 additions, 7 deletions"
+                )
+                expected_kwargs.update({"changed_files_stats": changed_files_stats})
+                expected_logs = self.get_expected("cli/test_cli/test_lint_staged_msg_filename_2", expected_kwargs)
+                self.assert_logged(expected_logs)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    def test_lint_staged_negative(self, _):
+        result = self.cli.invoke(cli.cli, ["--staged"])
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+        self.assertEqual(
+            result.output,
+            "Error: The 'staged' option (--staged) can only be used when using "
+            "'--msg-filename' or when piping data to gitlint via stdin.\n",
+        )
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_fail_without_commits(self, sh, _):
+        """Test for --debug option"""
+
+        sh.git.side_effect = ["", ""]  # First invocation of git rev-list  # Second invocation of git rev-list
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            # By default, gitlint should silently exit with code GITLINT_SUCCESS when there are no commits
+            result = self.cli.invoke(cli.cli, ["--commits", "foo..bar"])
+            self.assertEqual(stderr.getvalue(), "")
+            self.assertEqual(result.exit_code, cli.GITLINT_SUCCESS)
+            self.assert_log_contains('DEBUG: gitlint.cli No commits in range "foo..bar"')
+
+            # When --fail-without-commits is set, gitlint should hard fail with code USAGE_ERROR_CODE
+            self.clearlog()
+            result = self.cli.invoke(cli.cli, ["--commits", "foo..bar", "--fail-without-commits"])
+            self.assertEqual(result.output, 'Error: No commits in range "foo..bar"\n')
+            self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+            self.assert_log_contains('DEBUG: gitlint.cli No commits in range "foo..bar"')
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    def test_msg_filename(self, _):
+        expected_output = "3: B6 Body message is missing\n"
+
+        with self.tempdir() as tmpdir:
+            msg_filename = os.path.join(tmpdir, "msg")
+            with open(msg_filename, "w", encoding=FILE_ENCODING) as f:
+                f.write("Commït title\n")
+
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                result = self.cli.invoke(cli.cli, ["--msg-filename", msg_filename])
+                self.assertEqual(stderr.getvalue(), expected_output)
+                self.assertEqual(result.exit_code, 1)
+                self.assertEqual(result.output, "")
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tïtle \n")
+    def test_silent_mode(self, _):
+        """Test for --silent option"""
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--silent"])
+            self.assertEqual(stderr.getvalue(), "")
+            self.assertEqual(result.exit_code, 3)
+            self.assertEqual(result.output, "")
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tïtle \n")
+    def test_verbosity(self, _):
+        """Test for --verbosity option"""
+        # We only test -v and -vv, more testing is really not required here
+        # -v
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["-v"])
+            self.assertEqual(stderr.getvalue(), "1: T2\n1: T5\n3: B6\n")
+            self.assertEqual(result.exit_code, 3)
+            self.assertEqual(result.output, "")
+
+        # -vv
+        expected_output = (
+            "1: T2 Title has trailing whitespace\n"
+            + "1: T5 Title contains the word 'WIP' (case-insensitive)\n"
+            + "3: B6 Body message is missing\n"
+        )
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["-vv"], input="WIP: tïtle \n")
+            self.assertEqual(stderr.getvalue(), expected_output)
+            self.assertEqual(result.exit_code, 3)
+            self.assertEqual(result.output, "")
+
+        # -vvvv: not supported -> should print a config error
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["-vvvv"], input="WIP: tïtle \n")
+            self.assertEqual(stderr.getvalue(), "")
+            self.assertEqual(result.exit_code, CLITests.CONFIG_ERROR_CODE)
+            self.assertEqual(result.output, "Config Error: Option 'verbosity' must be set between 0 and 3\n")
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_debug(self, sh, _):
+        """Test for --debug option"""
+
+        # fmt: off
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360\n"  # git rev-list <SHA>
+            "25053ccec5e28e1bb8f7551fdbb5ab213ada2401\n"
+            "4da2656b0dadc76c7ee3fd0243a96cb64007f125\n",
+            # git log --pretty <FORMAT> <SHA>
+            "test åuthor1\x00test-email1@föo.com\x002016-12-03 15:28:15 +0100\x00a123\n"
+            "commït-title1\n\ncommït-body1",
+            "#",                                                     # git config --get core.commentchar
+            "5\t8\tcommit-1/file-1\n2\t9\tcommit-1/file-2\n",                    # git diff-tree
+            "commit-1-branch-1\ncommit-1-branch-2\n",                # git branch --contains <sha>
+            "test åuthor2\x00test-email2@föo.com\x002016-12-04 15:28:15 +0100\x00b123\n"
+            "commït-title2.\n\ncommït-body2",
+            "5\t8\tcommit-2/file-1\n7\t9\tcommit-2/file-2\n",        # git diff-tree
+            "commit-2-branch-1\ncommit-2-branch-2\n",                # git branch --contains <sha>
+            "test åuthor3\x00test-email3@föo.com\x002016-12-05 15:28:15 +0100\x00c123\n"
+            "föobar\nbar",
+            "1\t4\tcommit-3/file-1\n3\t4\tcommit-3/file-2\n",        # git diff-tree
+            "commit-3-branch-1\ncommit-3-branch-2\n",                # git branch --contains <sha>
+        ]
+        # fmt: on
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            config_path = self.get_sample_path(os.path.join("config", "gitlintconfig"))
+            result = self.cli.invoke(cli.cli, ["--config", config_path, "--debug", "--commits", "foo...bar"])
+
+            expected = (
+                "Commit 6f29bf81a8:\n3: B5\n\n"
+                "Commit 25053ccec5:\n1: T3\n3: B5\n\n"
+                "Commit 4da2656b0d:\n2: B4\n3: B5\n3: B6\n"
+            )
+
+            self.assertEqual(stderr.getvalue(), expected)
+            self.assertEqual(result.exit_code, 6)
+
+            expected_kwargs = self.get_system_info_dict()
+            changed_files_stats1 = (
+                f"  {os.path.join('commit-1', 'file-1')}: 5 additions, 8 deletions\n"
+                f"  {os.path.join('commit-1', 'file-2')}: 2 additions, 9 deletions"
+            )
+            changed_files_stats2 = (
+                f"  {os.path.join('commit-2', 'file-1')}: 5 additions, 8 deletions\n"
+                f"  {os.path.join('commit-2', 'file-2')}: 7 additions, 9 deletions"
+            )
+            changed_files_stats3 = (
+                f"  {os.path.join('commit-3', 'file-1')}: 1 additions, 4 deletions\n"
+                f"  {os.path.join('commit-3', 'file-2')}: 3 additions, 4 deletions"
+            )
+            expected_kwargs.update(
+                {
+                    "changed_files_stats1": changed_files_stats1,
+                    "changed_files_stats2": changed_files_stats2,
+                    "changed_files_stats3": changed_files_stats3,
+                }
+            )
+            expected_kwargs.update({"config_path": config_path})
+            expected_logs = self.get_expected("cli/test_cli/test_debug_1", expected_kwargs)
+            self.assert_logged(expected_logs)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="Test tïtle\n")
+    def test_extra_path(self, _):
+        """Test for --extra-path flag"""
+        # Test extra-path pointing to a directory
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            extra_path = self.get_sample_path("user_rules")
+            result = self.cli.invoke(cli.cli, ["--extra-path", extra_path])
+            expected_output = '1: UC1 Commit violåtion 1: "Contënt 1"\n' + "3: B6 Body message is missing\n"
+            self.assertEqual(stderr.getvalue(), expected_output)
+            self.assertEqual(result.exit_code, 2)
+
+        # Test extra-path pointing to a file
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            extra_path = self.get_sample_path(os.path.join("user_rules", "my_commit_rules.py"))
+            result = self.cli.invoke(cli.cli, ["--extra-path", extra_path])
+            expected_output = '1: UC1 Commit violåtion 1: "Contënt 1"\n' + "3: B6 Body message is missing\n"
+            self.assertEqual(stderr.getvalue(), expected_output)
+            self.assertEqual(result.exit_code, 2)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="Test tïtle\n")
+    def test_extra_path_environment(self, _):
+        """Test for GITLINT_EXTRA_PATH environment variable"""
+        # Test setting extra-path to a directory from an environment variable
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            extra_path = self.get_sample_path("user_rules")
+            result = self.cli.invoke(cli.cli, env={"GITLINT_EXTRA_PATH": extra_path})
+
+            expected_output = '1: UC1 Commit violåtion 1: "Contënt 1"\n' + "3: B6 Body message is missing\n"
+            self.assertEqual(stderr.getvalue(), expected_output)
+            self.assertEqual(result.exit_code, 2)
+
+        # Test extra-path pointing to a file from an environment variable
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            extra_path = self.get_sample_path(os.path.join("user_rules", "my_commit_rules.py"))
+            result = self.cli.invoke(cli.cli, env={"GITLINT_EXTRA_PATH": extra_path})
+            expected_output = '1: UC1 Commit violåtion 1: "Contënt 1"\n' + "3: B6 Body message is missing\n"
+            self.assertEqual(stderr.getvalue(), expected_output)
+            self.assertEqual(result.exit_code, 2)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="Test tïtle\n\nMy body that is long enough")
+    def test_contrib(self, _):
+        # Test enabled contrib rules
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--contrib", "contrib-title-conventional-commits,CC1"])
+            expected_output = self.get_expected("cli/test_cli/test_contrib_1")
+            self.assertEqual(stderr.getvalue(), expected_output)
+            self.assertEqual(result.exit_code, 2)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="Test tïtle\n")
+    def test_contrib_negative(self, _):
+        result = self.cli.invoke(cli.cli, ["--contrib", "föobar,CC1"])
+        self.assertEqual(result.output, "Config Error: No contrib rule with id or name 'föobar' found.\n")
+        self.assertEqual(result.exit_code, self.CONFIG_ERROR_CODE)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tëst")
+    def test_config_file(self, _):
+        """Test for --config option"""
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            config_path = self.get_sample_path(os.path.join("config", "gitlintconfig"))
+            result = self.cli.invoke(cli.cli, ["--config", config_path])
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5\n3: B6\n")
+            self.assertEqual(result.exit_code, 2)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tëst")
+    def test_config_file_environment(self, _):
+        """Test for GITLINT_CONFIG environment variable"""
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            config_path = self.get_sample_path(os.path.join("config", "gitlintconfig"))
+            result = self.cli.invoke(cli.cli, env={"GITLINT_CONFIG": config_path})
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5\n3: B6\n")
+            self.assertEqual(result.exit_code, 2)
+
+    def test_config_file_negative(self):
+        """Negative test for --config option"""
+        # Directory as config file
+        config_path = self.get_sample_path("config")
+        result = self.cli.invoke(cli.cli, ["--config", config_path])
+        expected_string = f"Error: Invalid value for '-C' / '--config': File '{config_path}' is a directory."
+        self.assertEqual(result.output.split("\n")[3], expected_string)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+
+        # Non existing file
+        config_path = self.get_sample_path("föo")
+        result = self.cli.invoke(cli.cli, ["--config", config_path])
+        expected_string = f"Error: Invalid value for '-C' / '--config': File {config_path!r} does not exist."
+        self.assertEqual(result.output.split("\n")[3], expected_string)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+
+        # Invalid config file
+        config_path = self.get_sample_path(os.path.join("config", "invalid-option-value"))
+        result = self.cli.invoke(cli.cli, ["--config", config_path])
+        self.assertEqual(result.exit_code, self.CONFIG_ERROR_CODE)
+
+    def test_config_file_negative_environment(self):
+        """Negative test for GITLINT_CONFIG environment variable"""
+        # Directory as config file
+        config_path = self.get_sample_path("config")
+        result = self.cli.invoke(cli.cli, env={"GITLINT_CONFIG": config_path})
+        expected_string = f"Error: Invalid value for '-C' / '--config': File '{config_path}' is a directory."
+        self.assertEqual(result.output.split("\n")[3], expected_string)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+
+        # Non existing file
+        config_path = self.get_sample_path("föo")
+        result = self.cli.invoke(cli.cli, env={"GITLINT_CONFIG": config_path})
+        expected_string = f"Error: Invalid value for '-C' / '--config': File {config_path!r} does not exist."
+        self.assertEqual(result.output.split("\n")[3], expected_string)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+
+        # Invalid config file
+        config_path = self.get_sample_path(os.path.join("config", "invalid-option-value"))
+        result = self.cli.invoke(cli.cli, env={"GITLINT_CONFIG": config_path})
+        self.assertEqual(result.exit_code, self.CONFIG_ERROR_CODE)
+
+    def test_config_error(self):
+        result = self.cli.invoke(cli.cli, ["-c", "foo.bar=hur"])
+        self.assertEqual(result.output, "Config Error: No such rule 'foo'\n")
+        self.assertEqual(result.exit_code, self.CONFIG_ERROR_CODE)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    def test_target(self, _):
+        """Test for the --target option"""
+        with self.tempdir() as tmpdir:
+            tmpdir_path = os.path.realpath(tmpdir)
+            os.environ["LANGUAGE"] = "C"  # Force language to english so we can check for error message
+            result = self.cli.invoke(cli.cli, ["--target", tmpdir_path])
+            # We expect gitlint to tell us that /tmp is not a git repo (this proves that it takes the target parameter
+            # into account).
+            self.assertEqual(result.output, "%s is not a git repository.\n" % tmpdir_path)
+            self.assertEqual(result.exit_code, self.GIT_CONTEXT_ERROR_CODE)
+
+    def test_target_negative(self):
+        """Negative test for the --target option"""
+        # try setting a non-existing target
+        result = self.cli.invoke(cli.cli, ["--target", "/föo/bar"])
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+        expected_msg = "Error: Invalid value for '--target': Directory '/föo/bar' does not exist."
+        self.assertEqual(result.output.split("\n")[3], expected_msg)
+
+        # try setting a file as target
+        target_path = self.get_sample_path(os.path.join("config", "gitlintconfig"))
+        result = self.cli.invoke(cli.cli, ["--target", target_path])
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+        expected_msg = f"Error: Invalid value for '--target': Directory {target_path!r} is a file."
+        self.assertEqual(result.output.split("\n")[3], expected_msg)
+
+    @patch("gitlint.config.LintConfigGenerator.generate_config")
+    def test_generate_config(self, generate_config):
+        """Test for the generate-config subcommand"""
+        result = self.cli.invoke(cli.cli, ["generate-config"], input="tëstfile\n")
+        self.assertEqual(result.exit_code, self.GITLINT_SUCCESS_CODE)
+        expected_msg = (
+            "Please specify a location for the sample gitlint config file [.gitlint]: tëstfile\n"
+            + f"Successfully generated {os.path.realpath('tëstfile')}\n"
+        )
+        self.assertEqual(result.output, expected_msg)
+        generate_config.assert_called_once_with(os.path.realpath("tëstfile"))
+
+    def test_generate_config_negative(self):
+        """Negative test for the generate-config subcommand"""
+        # Non-existing directory
+        fake_dir = os.path.abspath("/föo")
+        fake_path = os.path.join(fake_dir, "bar")
+        result = self.cli.invoke(cli.cli, ["generate-config"], input=fake_path)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+        expected_msg = (
+            f"Please specify a location for the sample gitlint config file [.gitlint]: {fake_path}\n"
+            + f"Error: Directory '{fake_dir}' does not exist.\n"
+        )
+        self.assertEqual(result.output, expected_msg)
+
+        # Existing file
+        sample_path = self.get_sample_path(os.path.join("config", "gitlintconfig"))
+        result = self.cli.invoke(cli.cli, ["generate-config"], input=sample_path)
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+        expected_msg = (
+            "Please specify a location for the sample gitlint "
+            f"config file [.gitlint]: {sample_path}\n"
+            f'Error: File "{sample_path}" already exists.\n'
+        )
+        self.assertEqual(result.output, expected_msg)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_git_error(self, sh, _):
+        """Tests that the cli handles git errors properly"""
+        sh.git.side_effect = CommandNotFound("git")
+        result = self.cli.invoke(cli.cli)
+        self.assertEqual(result.exit_code, self.GIT_CONTEXT_ERROR_CODE)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_no_commits_in_range(self, sh, _):
+        """Test for --commits with the specified range being empty."""
+        sh.git.side_effect = lambda *_args, **_kwargs: ""
+        result = self.cli.invoke(cli.cli, ["--commits", "main...HEAD"])
+
+        self.assert_log_contains('DEBUG: gitlint.cli No commits in range "main...HEAD"')
+        self.assertEqual(result.exit_code, self.GITLINT_SUCCESS_CODE)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: tëst tïtle")
+    def test_named_rules(self, _):
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            config_path = self.get_sample_path(os.path.join("config", "named-rules"))
+            result = self.cli.invoke(cli.cli, ["--config", config_path, "--debug"])
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli/test_named_rules_1"))
+            self.assertEqual(result.exit_code, 4)
+
+            # Assert debug logs are correct
+            expected_kwargs = self.get_system_info_dict()
+            expected_kwargs.update({"config_path": config_path})
+            expected_logs = self.get_expected("cli/test_cli/test_named_rules_2", expected_kwargs)
+            self.assert_logged(expected_logs)
diff --git a/gitlint-core/gitlint/tests/cli/test_cli_hooks.py b/gitlint-core/gitlint/tests/cli/test_cli_hooks.py
new file mode 100644
index 0000000..c9e4eba
--- /dev/null
+++ b/gitlint-core/gitlint/tests/cli/test_cli_hooks.py
@@ -0,0 +1,277 @@
+import os
+from io import StringIO
+from unittest.mock import patch
+
+from click.testing import CliRunner
+from gitlint import cli, config, hooks
+from gitlint.shell import ErrorReturnCode
+from gitlint.tests.base import BaseTestCase
+from gitlint.utils import FILE_ENCODING
+
+
+class CLIHookTests(BaseTestCase):
+    USAGE_ERROR_CODE = 253
+    GIT_CONTEXT_ERROR_CODE = 254
+    CONFIG_ERROR_CODE = 255
+
+    def setUp(self):
+        super().setUp()
+        self.cli = CliRunner()
+
+        # Patch gitlint.cli.git_version() so that we don't have to patch it separately in every test
+        self.git_version_path = patch("gitlint.cli.git_version")
+        cli.git_version = self.git_version_path.start()
+        cli.git_version.return_value = "git version 1.2.3"
+
+    def tearDown(self):
+        self.git_version_path.stop()
+
+    @patch("gitlint.hooks.GitHookInstaller.install_commit_msg_hook")
+    @patch("gitlint.hooks.git_hooks_dir", return_value=os.path.join("/hür", "dur"))
+    def test_install_hook(self, _, install_hook):
+        """Test for install-hook subcommand"""
+        result = self.cli.invoke(cli.cli, ["install-hook"])
+        expected_path = os.path.join("/hür", "dur", hooks.COMMIT_MSG_HOOK_DST_PATH)
+        expected = f"Successfully installed gitlint commit-msg hook in {expected_path}\n"
+        self.assertEqual(result.output, expected)
+        self.assertEqual(result.exit_code, 0)
+        expected_config = config.LintConfig()
+        expected_config.target = os.path.realpath(os.getcwd())
+        install_hook.assert_called_once_with(expected_config)
+
+    @patch("gitlint.hooks.GitHookInstaller.install_commit_msg_hook")
+    @patch("gitlint.hooks.git_hooks_dir", return_value=os.path.join("/hür", "dur"))
+    def test_install_hook_target(self, _, install_hook):
+        """Test for install-hook subcommand with a specific --target option specified"""
+        # Specified target
+        result = self.cli.invoke(cli.cli, ["--target", self.SAMPLES_DIR, "install-hook"])
+        expected_path = os.path.join("/hür", "dur", hooks.COMMIT_MSG_HOOK_DST_PATH)
+        expected = "Successfully installed gitlint commit-msg hook in %s\n" % expected_path
+        self.assertEqual(result.exit_code, 0)
+        self.assertEqual(result.output, expected)
+
+        expected_config = config.LintConfig()
+        expected_config.target = self.SAMPLES_DIR
+        install_hook.assert_called_once_with(expected_config)
+
+    @patch("gitlint.hooks.GitHookInstaller.install_commit_msg_hook", side_effect=hooks.GitHookInstallerError("tëst"))
+    def test_install_hook_negative(self, install_hook):
+        """Negative test for install-hook subcommand"""
+        result = self.cli.invoke(cli.cli, ["install-hook"])
+        self.assertEqual(result.exit_code, self.GIT_CONTEXT_ERROR_CODE)
+        self.assertEqual(result.output, "tëst\n")
+        expected_config = config.LintConfig()
+        expected_config.target = os.path.realpath(os.getcwd())
+        install_hook.assert_called_once_with(expected_config)
+
+    @patch("gitlint.hooks.GitHookInstaller.uninstall_commit_msg_hook")
+    @patch("gitlint.hooks.git_hooks_dir", return_value=os.path.join("/hür", "dur"))
+    def test_uninstall_hook(self, _, uninstall_hook):
+        """Test for uninstall-hook subcommand"""
+        result = self.cli.invoke(cli.cli, ["uninstall-hook"])
+        expected_path = os.path.join("/hür", "dur", hooks.COMMIT_MSG_HOOK_DST_PATH)
+        expected = f"Successfully uninstalled gitlint commit-msg hook from {expected_path}\n"
+        self.assertEqual(result.exit_code, 0)
+        self.assertEqual(result.output, expected)
+        expected_config = config.LintConfig()
+        expected_config.target = os.path.realpath(os.getcwd())
+        uninstall_hook.assert_called_once_with(expected_config)
+
+    @patch("gitlint.hooks.GitHookInstaller.uninstall_commit_msg_hook", side_effect=hooks.GitHookInstallerError("tëst"))
+    def test_uninstall_hook_negative(self, uninstall_hook):
+        """Negative test for uninstall-hook subcommand"""
+        result = self.cli.invoke(cli.cli, ["uninstall-hook"])
+        self.assertEqual(result.exit_code, self.GIT_CONTEXT_ERROR_CODE)
+        self.assertEqual(result.output, "tëst\n")
+        expected_config = config.LintConfig()
+        expected_config.target = os.path.realpath(os.getcwd())
+        uninstall_hook.assert_called_once_with(expected_config)
+
+    def test_run_hook_no_tty(self):
+        """Test for run-hook subcommand.
+        When no TTY is available (like is the case for this test), the hook will abort after the first check.
+        """
+
+        # No need to patch git as we're passing a msg-filename to run-hook, so no git calls are made.
+        # Note that this is the case when passing --staged as well, but that's tested as part of the integration tests
+        # (=end-to-end scenario).
+
+        # Ideally we'd be able to assert that run-hook internally calls the lint cli command, but couldn't make
+        # that work. Have tried many different variatons of mocking and patching without avail. For now, we just
+        # check the output which indirectly proves the same thing.
+
+        with self.tempdir() as tmpdir:
+            msg_filename = os.path.join(tmpdir, "hür")
+            with open(msg_filename, "w", encoding=FILE_ENCODING) as f:
+                f.write("WIP: tïtle\n")
+
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                result = self.cli.invoke(cli.cli, ["--msg-filename", msg_filename, "run-hook"])
+                self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_hook_no_tty_1_stdout"))
+                self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli_hooks/test_hook_no_tty_1_stderr"))
+
+                # exit code is 1 because aborted (no stdin available)
+                self.assertEqual(result.exit_code, 1)
+
+    @patch("gitlint.cli.shell")
+    def test_run_hook_edit(self, shell):
+        """Test for run-hook subcommand, answering 'e(dit)' after commit-hook"""
+
+        set_editors = [None, "myeditor"]
+        expected_editors = ["vim -n", "myeditor"]
+        commit_messages = ["WIP: höok edit 1", "WIP: höok edit 2"]
+
+        for i in range(0, len(set_editors)):
+            if set_editors[i]:
+                os.environ["EDITOR"] = set_editors[i]
+            else:
+                # When set_editors[i] == None, ensure we don't fallback to EDITOR set in shell invocating the tests
+                os.environ.pop("EDITOR", None)
+
+            with self.patch_input(["e", "e", "n"]), self.tempdir() as tmpdir:
+                msg_filename = os.path.realpath(os.path.join(tmpdir, "hür"))
+                with open(msg_filename, "w", encoding=FILE_ENCODING) as f:
+                    f.write(commit_messages[i] + "\n")
+
+                with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                    result = self.cli.invoke(cli.cli, ["--msg-filename", msg_filename, "run-hook"])
+                    self.assertEqual(
+                        result.output,
+                        self.get_expected(
+                            "cli/test_cli_hooks/test_hook_edit_1_stdout", {"commit_msg": commit_messages[i]}
+                        ),
+                    )
+                    expected = self.get_expected(
+                        "cli/test_cli_hooks/test_hook_edit_1_stderr", {"commit_msg": commit_messages[i]}
+                    )
+                    self.assertEqual(stderr.getvalue(), expected)
+
+                    # exit code = number of violations
+                    self.assertEqual(result.exit_code, 2)
+
+                    shell.assert_called_with(expected_editors[i] + " " + msg_filename)
+                    self.assert_log_contains("DEBUG: gitlint.cli run-hook: editing commit message")
+                    self.assert_log_contains(f"DEBUG: gitlint.cli run-hook: {expected_editors[i]} {msg_filename}")
+
+    def test_run_hook_no(self):
+        """Test for run-hook subcommand, answering 'n(o)' after commit-hook"""
+
+        with self.patch_input(["n"]), self.tempdir() as tmpdir:
+            msg_filename = os.path.join(tmpdir, "hür")
+            with open(msg_filename, "w", encoding=FILE_ENCODING) as f:
+                f.write("WIP: höok no\n")
+
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                result = self.cli.invoke(cli.cli, ["--msg-filename", msg_filename, "run-hook"])
+                self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_hook_no_1_stdout"))
+                self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli_hooks/test_hook_no_1_stderr"))
+
+                # We decided not to keep the commit message: hook returns number of violations (>0)
+                # This will cause git to abort the commit
+                self.assertEqual(result.exit_code, 2)
+                self.assert_log_contains("DEBUG: gitlint.cli run-hook: commit message declined")
+
+    def test_run_hook_yes(self):
+        """Test for run-hook subcommand, answering 'y(es)' after commit-hook"""
+        with self.patch_input(["y"]), self.tempdir() as tmpdir:
+            msg_filename = os.path.join(tmpdir, "hür")
+            with open(msg_filename, "w", encoding=FILE_ENCODING) as f:
+                f.write("WIP: höok yes\n")
+
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                result = self.cli.invoke(cli.cli, ["--msg-filename", msg_filename, "run-hook"])
+                self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_hook_yes_1_stdout"))
+                self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli_hooks/test_hook_yes_1_stderr"))
+
+                # Exit code is 0 because we decide to keep the commit message
+                # This will cause git to keep the commit
+                self.assertEqual(result.exit_code, 0)
+                self.assert_log_contains("DEBUG: gitlint.cli run-hook: commit message accepted")
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_run_hook_negative(self, sh, _):
+        """Negative test for the run-hook subcommand: testing whether exceptions are correctly handled when
+        running `gitlint run-hook`.
+        """
+        # GIT_CONTEXT_ERROR_CODE: git error
+        error_msg = b"fatal: not a git repository (or any of the parent directories): .git"
+        sh.git.side_effect = ErrorReturnCode("full command", b"stdout", error_msg)
+        result = self.cli.invoke(cli.cli, ["run-hook"])
+        expected_kwargs = {"git_repo": os.path.realpath(os.getcwd())}
+        expected = self.get_expected("cli/test_cli_hooks/test_run_hook_negative_1", expected_kwargs)
+        self.assertEqual(result.output, expected)
+        self.assertEqual(result.exit_code, self.GIT_CONTEXT_ERROR_CODE)
+
+        # USAGE_ERROR_CODE: incorrect use of gitlint
+        result = self.cli.invoke(cli.cli, ["--staged", "run-hook"])
+        self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_run_hook_negative_2"))
+        self.assertEqual(result.exit_code, self.USAGE_ERROR_CODE)
+
+        # CONFIG_ERROR_CODE: incorrect config. Note that this is handled before the hook even runs
+        result = self.cli.invoke(cli.cli, ["-c", "föo.bár=1", "run-hook"])
+        self.assertEqual(result.output, "Config Error: No such rule 'föo'\n")
+        self.assertEqual(result.exit_code, self.CONFIG_ERROR_CODE)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: Test hook stdin tïtle\n")
+    def test_run_hook_stdin_violations(self, _):
+        """Test for passing stdin data to run-hook, expecting some violations. Equivalent of:
+        $ echo "WIP: Test hook stdin tïtle" | gitlint run-hook
+        """
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["run-hook"])
+            expected_stderr = self.get_expected("cli/test_cli_hooks/test_hook_stdin_violations_1_stderr")
+            self.assertEqual(stderr.getvalue(), expected_stderr)
+            self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_hook_stdin_violations_1_stdout"))
+            # Hook will auto-abort because we're using stdin. Abort = exit code 1
+            self.assertEqual(result.exit_code, 1)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="Test tïtle\n\nTest bödy that is long enough")
+    def test_run_hook_stdin_no_violations(self, _):
+        """Test for passing stdin data to run-hook, expecting *NO* violations, Equivalent of:
+        $ echo -e "Test tïtle\n\nTest bödy that is long enough" | gitlint run-hook
+        """
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["run-hook"])
+            self.assertEqual(stderr.getvalue(), "")  # no errors = no stderr output
+            expected_stdout = self.get_expected("cli/test_cli_hooks/test_hook_stdin_no_violations_1_stdout")
+            self.assertEqual(result.output, expected_stdout)
+            self.assertEqual(result.exit_code, 0)
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: Test hook config tïtle\n")
+    def test_run_hook_config(self, _):
+        """Test that gitlint still respects config when running run-hook, equivalent of:
+        $ echo "WIP: Test hook config tïtle" | gitlint -c title-max-length.line-length=5 --ignore B6 run-hook
+        """
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["-c", "title-max-length.line-length=5", "--ignore", "B6", "run-hook"])
+            self.assertEqual(stderr.getvalue(), self.get_expected("cli/test_cli_hooks/test_hook_config_1_stderr"))
+            self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_hook_config_1_stdout"))
+            # Hook will auto-abort because we're using stdin. Abort = exit code 1
+            self.assertEqual(result.exit_code, 1)
+
+    @patch("gitlint.cli.get_stdin_data", return_value=False)
+    @patch("gitlint.git.sh")
+    def test_run_hook_local_commit(self, sh, _):
+        """Test running the hook on the last commit-msg from the local repo, equivalent of:
+        $ gitlint run-hook
+        and then choosing 'e'
+        """
+        sh.git.side_effect = [
+            "6f29bf81a8322a04071bb794666e48c443a90360",
+            "test åuthor\x00test-email@föo.com\x002016-12-03 15:28:15 +0100\x00åbc\nWIP: commït-title\n\ncommït-body",
+            "#",  # git config --get core.commentchar
+            "1\t5\tfile1.txt\n3\t4\tpåth/to/file2.txt\n",
+            "commit-1-branch-1\ncommit-1-branch-2\n",
+        ]
+
+        with self.patch_input(["e"]), patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["run-hook"])
+            expected = self.get_expected("cli/test_cli_hooks/test_hook_local_commit_1_stderr")
+            self.assertEqual(stderr.getvalue(), expected)
+            self.assertEqual(result.output, self.get_expected("cli/test_cli_hooks/test_hook_local_commit_1_stdout"))
+            # If we can't edit the message, run-hook follows regular gitlint behavior and exit code = # violations
+            self.assertEqual(result.exit_code, 2)
diff --git a/gitlint-core/gitlint/tests/config/test_config.py b/gitlint-core/gitlint/tests/config/test_config.py
new file mode 100644
index 0000000..439fd93
--- /dev/null
+++ b/gitlint-core/gitlint/tests/config/test_config.py
@@ -0,0 +1,320 @@
+from unittest.mock import patch
+
+from gitlint import options, rules
+from gitlint.config import (
+    GITLINT_CONFIG_TEMPLATE_SRC_PATH,
+    LintConfig,
+    LintConfigError,
+    LintConfigGenerator,
+)
+from gitlint.tests.base import BaseTestCase
+
+
+class LintConfigTests(BaseTestCase):
+    def test_set_rule_option(self):
+        config = LintConfig()
+
+        # assert default title line-length
+        self.assertEqual(config.get_rule_option("title-max-length", "line-length"), 72)
+
+        # change line length and assert it is set
+        config.set_rule_option("title-max-length", "line-length", 60)
+        self.assertEqual(config.get_rule_option("title-max-length", "line-length"), 60)
+
+    def test_set_rule_option_negative(self):
+        config = LintConfig()
+
+        # non-existing rule
+        expected_error_msg = "No such rule 'föobar'"
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config.set_rule_option("föobar", "lïne-length", 60)
+
+        # non-existing option
+        expected_error_msg = "Rule 'title-max-length' has no option 'föobar'"
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config.set_rule_option("title-max-length", "föobar", 60)
+
+        # invalid option value
+        expected_error_msg = (
+            "'föo' is not a valid value for option 'title-max-length.line-length'. "
+            "Option 'line-length' must be a positive integer (current value: 'föo')."
+        )
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config.set_rule_option("title-max-length", "line-length", "föo")
+
+    def test_set_general_option(self):
+        config = LintConfig()
+
+        # Check that default general options are correct
+        self.assertTrue(config.ignore_merge_commits)
+        self.assertTrue(config.ignore_fixup_commits)
+        self.assertTrue(config.ignore_fixup_amend_commits)
+        self.assertTrue(config.ignore_squash_commits)
+        self.assertTrue(config.ignore_revert_commits)
+
+        self.assertFalse(config.ignore_stdin)
+        self.assertFalse(config.staged)
+        self.assertFalse(config.fail_without_commits)
+        self.assertFalse(config.regex_style_search)
+        self.assertFalse(config.debug)
+        self.assertEqual(config.verbosity, 3)
+        active_rule_classes = tuple(type(rule) for rule in config.rules)
+        self.assertTupleEqual(active_rule_classes, config.default_rule_classes)
+
+        # ignore - set by string
+        config.set_general_option("ignore", "title-trailing-whitespace, B2")
+        self.assertEqual(config.ignore, ["title-trailing-whitespace", "B2"])
+
+        # ignore - set by list
+        config.set_general_option("ignore", ["T1", "B3"])
+        self.assertEqual(config.ignore, ["T1", "B3"])
+
+        # verbosity
+        config.set_general_option("verbosity", 1)
+        self.assertEqual(config.verbosity, 1)
+
+        # ignore_merge_commit
+        config.set_general_option("ignore-merge-commits", "false")
+        self.assertFalse(config.ignore_merge_commits)
+
+        # ignore_fixup_commit
+        config.set_general_option("ignore-fixup-commits", "false")
+        self.assertFalse(config.ignore_fixup_commits)
+
+        # ignore_fixup_amend_commit
+        config.set_general_option("ignore-fixup-amend-commits", "false")
+        self.assertFalse(config.ignore_fixup_amend_commits)
+
+        # ignore_squash_commit
+        config.set_general_option("ignore-squash-commits", "false")
+        self.assertFalse(config.ignore_squash_commits)
+
+        # ignore_revert_commit
+        config.set_general_option("ignore-revert-commits", "false")
+        self.assertFalse(config.ignore_revert_commits)
+
+        # debug
+        config.set_general_option("debug", "true")
+        self.assertTrue(config.debug)
+
+        # ignore-stdin
+        config.set_general_option("ignore-stdin", "true")
+        self.assertTrue(config.debug)
+
+        # staged
+        config.set_general_option("staged", "true")
+        self.assertTrue(config.staged)
+
+        # fail-without-commits
+        config.set_general_option("fail-without-commits", "true")
+        self.assertTrue(config.fail_without_commits)
+
+        # regex-style-search
+        config.set_general_option("regex-style-search", "true")
+        self.assertTrue(config.regex_style_search)
+
+        # target
+        config.set_general_option("target", self.SAMPLES_DIR)
+        self.assertEqual(config.target, self.SAMPLES_DIR)
+
+        # extra_path has its own test: test_extra_path and test_extra_path_negative
+        # contrib has its own tests: test_contrib and test_contrib_negative
+
+    def test_contrib(self):
+        config = LintConfig()
+        contrib_rules = ["contrib-title-conventional-commits", "CC1"]
+        config.set_general_option("contrib", ",".join(contrib_rules))
+        self.assertEqual(config.contrib, contrib_rules)
+
+        # Check contrib-title-conventional-commits contrib rule
+        actual_rule = config.rules.find_rule("contrib-title-conventional-commits")
+        self.assertTrue(actual_rule.is_contrib)
+
+        self.assertEqual(str(type(actual_rule)), "<class 'conventional_commit.ConventionalCommit'>")
+        self.assertEqual(actual_rule.id, "CT1")
+        self.assertEqual(actual_rule.name, "contrib-title-conventional-commits")
+        self.assertEqual(actual_rule.target, rules.CommitMessageTitle)
+
+        expected_rule_option = options.ListOption(
+            "types",
+            ["fix", "feat", "chore", "docs", "style", "refactor", "perf", "test", "revert", "ci", "build"],
+            "Comma separated list of allowed commit types.",
+        )
+
+        self.assertListEqual(actual_rule.options_spec, [expected_rule_option])
+        self.assertDictEqual(actual_rule.options, {"types": expected_rule_option})
+
+        # Check contrib-body-requires-signed-off-by contrib rule
+        actual_rule = config.rules.find_rule("contrib-body-requires-signed-off-by")
+        self.assertTrue(actual_rule.is_contrib)
+
+        self.assertEqual(str(type(actual_rule)), "<class 'signedoff_by.SignedOffBy'>")
+        self.assertEqual(actual_rule.id, "CC1")
+        self.assertEqual(actual_rule.name, "contrib-body-requires-signed-off-by")
+
+        # reset value (this is a different code path)
+        config.set_general_option("contrib", "contrib-body-requires-signed-off-by")
+        self.assertEqual(actual_rule, config.rules.find_rule("contrib-body-requires-signed-off-by"))
+        self.assertIsNone(config.rules.find_rule("contrib-title-conventional-commits"))
+
+        # empty value
+        config.set_general_option("contrib", "")
+        self.assertListEqual(config.contrib, [])
+
+    def test_contrib_negative(self):
+        config = LintConfig()
+        # non-existent contrib rule
+        with self.assertRaisesMessage(LintConfigError, "No contrib rule with id or name 'föo' found."):
+            config.contrib = "contrib-title-conventional-commits,föo"
+
+        # UserRuleError, RuleOptionError should be re-raised as LintConfigErrors
+        side_effects = [rules.UserRuleError("üser-rule"), options.RuleOptionError("rüle-option")]
+        for side_effect in side_effects:
+            with patch("gitlint.config.rule_finder.find_rule_classes", side_effect=side_effect):  # noqa: SIM117
+                with self.assertRaisesMessage(LintConfigError, str(side_effect)):
+                    config.contrib = "contrib-title-conventional-commits"
+
+    def test_extra_path(self):
+        config = LintConfig()
+
+        config.set_general_option("extra-path", self.get_user_rules_path())
+        self.assertEqual(config.extra_path, self.get_user_rules_path())
+        actual_rule = config.rules.find_rule("UC1")
+        self.assertTrue(actual_rule.is_user_defined)
+        self.assertEqual(str(type(actual_rule)), "<class 'my_commit_rules.MyUserCommitRule'>")
+        self.assertEqual(actual_rule.id, "UC1")
+        self.assertEqual(actual_rule.name, "my-üser-commit-rule")
+        self.assertEqual(actual_rule.target, None)
+        expected_rule_option = options.IntOption("violation-count", 1, "Number of violåtions to return")
+        self.assertListEqual(actual_rule.options_spec, [expected_rule_option])
+        self.assertDictEqual(actual_rule.options, {"violation-count": expected_rule_option})
+
+        # reset value (this is a different code path)
+        config.set_general_option("extra-path", self.SAMPLES_DIR)
+        self.assertEqual(config.extra_path, self.SAMPLES_DIR)
+        self.assertIsNone(config.rules.find_rule("UC1"))
+
+    def test_extra_path_negative(self):
+        config = LintConfig()
+        regex = "Option extra-path must be either an existing directory or file (current value: 'föo/bar')"
+        # incorrect extra_path
+        with self.assertRaisesMessage(LintConfigError, regex):
+            config.extra_path = "föo/bar"
+
+        # extra path contains classes with errors
+        with self.assertRaisesMessage(
+            LintConfigError, "User-defined rule class 'MyUserLineRule' must have a 'validate' method"
+        ):
+            config.extra_path = self.get_sample_path("user_rules/incorrect_linerule")
+
+    def test_set_general_option_negative(self):
+        config = LintConfig()
+
+        # Note that we shouldn't test whether we can set unicode because python just doesn't allow unicode attributes
+        with self.assertRaisesMessage(LintConfigError, "'foo' is not a valid gitlint option"):
+            config.set_general_option("foo", "bår")
+
+        # try setting _config_path, this is a real attribute of LintConfig, but the code should prevent it from
+        # being set
+        with self.assertRaisesMessage(LintConfigError, "'_config_path' is not a valid gitlint option"):
+            config.set_general_option("_config_path", "bår")
+
+        # invalid verbosity
+        incorrect_values = [-1, "föo"]
+        for value in incorrect_values:
+            expected_msg = f"Option 'verbosity' must be a positive integer (current value: '{value}')"
+            with self.assertRaisesMessage(LintConfigError, expected_msg):
+                config.verbosity = value
+
+        incorrect_values = [4]
+        for value in incorrect_values:
+            with self.assertRaisesMessage(LintConfigError, "Option 'verbosity' must be set between 0 and 3"):
+                config.verbosity = value
+
+        # invalid ignore_xxx_commits
+        ignore_attributes = [
+            "ignore_merge_commits",
+            "ignore_fixup_commits",
+            "ignore_fixup_amend_commits",
+            "ignore_squash_commits",
+            "ignore_revert_commits",
+        ]
+        incorrect_values = [-1, 4, "föo"]
+        for attribute in ignore_attributes:
+            for value in incorrect_values:
+                option_name = attribute.replace("_", "-")
+                with self.assertRaisesMessage(
+                    LintConfigError, f"Option '{option_name}' must be either 'true' or 'false'"
+                ):
+                    setattr(config, attribute, value)
+
+        # invalid ignore -> not here because ignore is a ListOption which converts everything to a string before
+        # splitting which means it it will accept just about everything
+
+        # invalid boolean options
+        for attribute in ["debug", "staged", "ignore_stdin", "fail_without_commits", "regex_style_search"]:
+            option_name = attribute.replace("_", "-")
+            with self.assertRaisesMessage(LintConfigError, f"Option '{option_name}' must be either 'true' or 'false'"):
+                setattr(config, attribute, "föobar")
+
+        # extra-path has its own negative test
+
+        # invalid target
+        with self.assertRaisesMessage(
+            LintConfigError, "Option target must be an existing directory (current value: 'föo/bar')"
+        ):
+            config.target = "föo/bar"
+
+    def test_ignore_independent_from_rules(self):
+        # Test that the lintconfig rules are not modified when setting config.ignore
+        # This was different in the past, this test is mostly here to catch regressions
+        config = LintConfig()
+        original_rules = config.rules
+        config.ignore = ["T1", "T2"]
+        self.assertEqual(config.ignore, ["T1", "T2"])
+        self.assertSequenceEqual(config.rules, original_rules)
+
+    def test_config_equality(self):
+        self.assertEqual(LintConfig(), LintConfig())
+        self.assertNotEqual(LintConfig(), LintConfigGenerator())
+
+        # Ensure LintConfig are not equal if they differ on their attributes
+        attrs = [
+            ("verbosity", 1),
+            ("rules", []),
+            ("ignore_stdin", True),
+            ("fail_without_commits", True),
+            ("regex_style_search", True),
+            ("debug", True),
+            ("ignore", ["T1"]),
+            ("staged", True),
+            ("_config_path", self.get_sample_path()),
+            ("ignore_merge_commits", False),
+            ("ignore_fixup_commits", False),
+            ("ignore_fixup_amend_commits", False),
+            ("ignore_squash_commits", False),
+            ("ignore_revert_commits", False),
+            ("extra_path", self.get_sample_path("user_rules")),
+            ("target", self.get_sample_path()),
+            ("contrib", ["CC1"]),
+        ]
+        for attr, val in attrs:
+            config = LintConfig()
+            setattr(config, attr, val)
+            self.assertNotEqual(LintConfig(), config)
+
+        # Other attributes don't matter
+        config1 = LintConfig()
+        config2 = LintConfig()
+        config1.foo = "bår"
+        self.assertEqual(config1, config2)
+        config2.foo = "dūr"
+        self.assertEqual(config1, config2)
+
+
+class LintConfigGeneratorTests(BaseTestCase):
+    @staticmethod
+    @patch("gitlint.config.shutil.copyfile")
+    def test_install_commit_msg_hook_negative(copy):
+        LintConfigGenerator.generate_config("föo/bar/test")
+        copy.assert_called_with(GITLINT_CONFIG_TEMPLATE_SRC_PATH, "föo/bar/test")
diff --git a/gitlint-core/gitlint/tests/config/test_config_builder.py b/gitlint-core/gitlint/tests/config/test_config_builder.py
new file mode 100644
index 0000000..ac2a896
--- /dev/null
+++ b/gitlint-core/gitlint/tests/config/test_config_builder.py
@@ -0,0 +1,275 @@
+import copy
+
+from gitlint import rules
+from gitlint.config import LintConfig, LintConfigBuilder, LintConfigError
+from gitlint.tests.base import BaseTestCase
+
+
+class LintConfigBuilderTests(BaseTestCase):
+    def test_set_option(self):
+        config_builder = LintConfigBuilder()
+        config = config_builder.build()
+
+        # assert some defaults
+        self.assertEqual(config.get_rule_option("title-max-length", "line-length"), 72)
+        self.assertEqual(config.get_rule_option("body-max-line-length", "line-length"), 80)
+        self.assertListEqual(config.get_rule_option("title-must-not-contain-word", "words"), ["WIP"])
+        self.assertEqual(config.verbosity, 3)
+
+        # Make some changes and check blueprint
+        config_builder.set_option("title-max-length", "line-length", 100)
+        config_builder.set_option("general", "verbosity", 2)
+        config_builder.set_option("title-must-not-contain-word", "words", ["foo", "bar"])
+        expected_blueprint = {
+            "title-must-not-contain-word": {"words": ["foo", "bar"]},
+            "title-max-length": {"line-length": 100},
+            "general": {"verbosity": 2},
+        }
+        self.assertDictEqual(config_builder._config_blueprint, expected_blueprint)
+
+        # Build config and verify that the changes have occurred and no other changes
+        config = config_builder.build()
+        self.assertEqual(config.get_rule_option("title-max-length", "line-length"), 100)
+        self.assertEqual(config.get_rule_option("body-max-line-length", "line-length"), 80)  # should be unchanged
+        self.assertListEqual(config.get_rule_option("title-must-not-contain-word", "words"), ["foo", "bar"])
+        self.assertEqual(config.verbosity, 2)
+
+    def test_set_from_commit_ignore_all(self):
+        config = LintConfig()
+        original_rules = config.rules
+        original_rule_ids = [rule.id for rule in original_rules]
+
+        config_builder = LintConfigBuilder()
+
+        # nothing gitlint
+        config_builder.set_config_from_commit(self.gitcommit("tëst\ngitlint\nfoo"))
+        config = config_builder.build()
+        self.assertSequenceEqual(config.rules, original_rules)
+        self.assertListEqual(config.ignore, [])
+
+        # ignore all rules
+        config_builder.set_config_from_commit(self.gitcommit("tëst\ngitlint-ignore: all\nfoo"))
+        config = config_builder.build()
+        self.assertEqual(config.ignore, original_rule_ids)
+
+        # ignore all rules, no space
+        config_builder.set_config_from_commit(self.gitcommit("tëst\ngitlint-ignore:all\nfoo"))
+        config = config_builder.build()
+        self.assertEqual(config.ignore, original_rule_ids)
+
+        # ignore all rules, more spacing
+        config_builder.set_config_from_commit(self.gitcommit("tëst\ngitlint-ignore: \t all\nfoo"))
+        config = config_builder.build()
+        self.assertEqual(config.ignore, original_rule_ids)
+
+    def test_set_from_commit_ignore_specific(self):
+        # ignore specific rules
+        config_builder = LintConfigBuilder()
+        config_builder.set_config_from_commit(self.gitcommit("tëst\ngitlint-ignore: T1, body-hard-tab"))
+        config = config_builder.build()
+        self.assertEqual(config.ignore, ["T1", "body-hard-tab"])
+
+    def test_set_from_config_file(self):
+        # regular config file load, no problems
+        config_builder = LintConfigBuilder()
+        config_builder.set_from_config_file(self.get_sample_path("config/gitlintconfig"))
+        config = config_builder.build()
+
+        # Do some assertions on the config
+        self.assertEqual(config.verbosity, 1)
+        self.assertFalse(config.debug)
+        self.assertFalse(config.ignore_merge_commits)
+        self.assertIsNone(config.extra_path)
+        self.assertEqual(config.ignore, ["title-trailing-whitespace", "B2"])
+
+        self.assertEqual(config.get_rule_option("title-max-length", "line-length"), 20)
+        self.assertEqual(config.get_rule_option("body-max-line-length", "line-length"), 30)
+
+    def test_set_from_config_file_negative(self):
+        config_builder = LintConfigBuilder()
+
+        # bad config file load
+        foo_path = self.get_sample_path("föo")
+        expected_error_msg = f"Invalid file path: {foo_path}"
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config_builder.set_from_config_file(foo_path)
+
+        # error during file parsing
+        path = self.get_sample_path("config/no-sections")
+        expected_error_msg = "File contains no section headers."
+        # We only match the start of the message here, since the exact message can vary depending on platform
+        with self.assertRaisesRegex(LintConfigError, expected_error_msg):
+            config_builder.set_from_config_file(path)
+
+        # non-existing rule
+        path = self.get_sample_path("config/nonexisting-rule")
+        config_builder = LintConfigBuilder()
+        config_builder.set_from_config_file(path)
+        expected_error_msg = "No such rule 'föobar'"
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config_builder.build()
+
+        # non-existing general option
+        path = self.get_sample_path("config/nonexisting-general-option")
+        config_builder = LintConfigBuilder()
+        config_builder.set_from_config_file(path)
+        expected_error_msg = "'foo' is not a valid gitlint option"
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config_builder.build()
+
+        # non-existing option
+        path = self.get_sample_path("config/nonexisting-option")
+        config_builder = LintConfigBuilder()
+        config_builder.set_from_config_file(path)
+        expected_error_msg = "Rule 'title-max-length' has no option 'föobar'"
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config_builder.build()
+
+        # invalid option value
+        path = self.get_sample_path("config/invalid-option-value")
+        config_builder = LintConfigBuilder()
+        config_builder.set_from_config_file(path)
+        expected_error_msg = (
+            "'föo' is not a valid value for option 'title-max-length.line-length'. "
+            "Option 'line-length' must be a positive integer (current value: 'föo')."
+        )
+        with self.assertRaisesMessage(LintConfigError, expected_error_msg):
+            config_builder.build()
+
+    def test_set_config_from_string_list(self):
+        config = LintConfig()
+
+        # change and assert changes
+        config_builder = LintConfigBuilder()
+        config_builder.set_config_from_string_list(
+            [
+                "general.verbosity=1",
+                "title-max-length.line-length=60",
+                "body-max-line-length.line-length=120",
+                "title-must-not-contain-word.words=håha",
+            ]
+        )
+
+        config = config_builder.build()
+        self.assertEqual(config.get_rule_option("title-max-length", "line-length"), 60)
+        self.assertEqual(config.get_rule_option("body-max-line-length", "line-length"), 120)
+        self.assertListEqual(config.get_rule_option("title-must-not-contain-word", "words"), ["håha"])
+        self.assertEqual(config.verbosity, 1)
+
+    def test_set_config_from_string_list_negative(self):
+        config_builder = LintConfigBuilder()
+
+        # assert error on incorrect rule - this happens at build time
+        config_builder.set_config_from_string_list(["föo.bar=1"])
+        with self.assertRaisesMessage(LintConfigError, "No such rule 'föo'"):
+            config_builder.build()
+
+        # no equal sign
+        expected_msg = "'föo.bar' is an invalid configuration option. Use '<rule>.<option>=<value>'"
+        with self.assertRaisesMessage(LintConfigError, expected_msg):
+            config_builder.set_config_from_string_list(["föo.bar"])
+
+        # missing value
+        expected_msg = "'föo.bar=' is an invalid configuration option. Use '<rule>.<option>=<value>'"
+        with self.assertRaisesMessage(LintConfigError, expected_msg):
+            config_builder.set_config_from_string_list(["föo.bar="])
+
+        # space instead of equal sign
+        expected_msg = "'föo.bar 1' is an invalid configuration option. Use '<rule>.<option>=<value>'"
+        with self.assertRaisesMessage(LintConfigError, expected_msg):
+            config_builder.set_config_from_string_list(["föo.bar 1"])
+
+        # no period between rule and option names
+        expected_msg = "'föobar=1' is an invalid configuration option. Use '<rule>.<option>=<value>'"
+        with self.assertRaisesMessage(LintConfigError, expected_msg):
+            config_builder.set_config_from_string_list(["föobar=1"])
+
+    def test_rebuild_config(self):
+        # normal config build
+        config_builder = LintConfigBuilder()
+        config_builder.set_option("general", "verbosity", 3)
+        lint_config = config_builder.build()
+        self.assertEqual(lint_config.verbosity, 3)
+
+        # check that existing config gets overwritten when we pass it to a configbuilder with different options
+        existing_lintconfig = LintConfig()
+        existing_lintconfig.verbosity = 2
+        lint_config = config_builder.build(existing_lintconfig)
+        self.assertEqual(lint_config.verbosity, 3)
+        self.assertEqual(existing_lintconfig.verbosity, 3)
+
+    def test_clone(self):
+        config_builder = LintConfigBuilder()
+        config_builder.set_option("general", "verbosity", 2)
+        config_builder.set_option("title-max-length", "line-length", 100)
+        expected = {"title-max-length": {"line-length": 100}, "general": {"verbosity": 2}}
+        self.assertDictEqual(config_builder._config_blueprint, expected)
+
+        # Clone and verify that the blueprint is the same as the original
+        cloned_builder = config_builder.clone()
+        self.assertDictEqual(cloned_builder._config_blueprint, expected)
+
+        # Modify the original and make sure we're not modifying the clone (i.e. check that the copy is a deep copy)
+        config_builder.set_option("title-max-length", "line-length", 120)
+        self.assertDictEqual(cloned_builder._config_blueprint, expected)
+
+    def test_named_rules(self):
+        # Store a copy of the default rules from the config, so we can reference it later
+        config_builder = LintConfigBuilder()
+        config = config_builder.build()
+        default_rules = copy.deepcopy(config.rules)
+        self.assertEqual(default_rules, config.rules)  # deepcopy should be equal
+
+        # Add a named rule by setting an option in the config builder that follows the named rule pattern
+        # Assert that whitespace in the rule name is stripped
+        rule_qualifiers = [
+            "T7:my-extra-rüle",
+            " T7 :   my-extra-rüle  ",
+            "\tT7:\tmy-extra-rüle\t",
+            "T7:\t\n  \tmy-extra-rüle\t\n\n",
+            "title-match-regex:my-extra-rüle",
+        ]
+        for rule_qualifier in rule_qualifiers:
+            config_builder = LintConfigBuilder()
+            config_builder.set_option(rule_qualifier, "regex", "föo")
+
+            expected_rules = copy.deepcopy(default_rules)
+            my_rule = rules.TitleRegexMatches({"regex": "föo"})
+            my_rule.id = rules.TitleRegexMatches.id + ":my-extra-rüle"
+            my_rule.name = rules.TitleRegexMatches.name + ":my-extra-rüle"
+            expected_rules._rules["T7:my-extra-rüle"] = my_rule
+            self.assertEqual(config_builder.build().rules, expected_rules)
+
+            # assert that changing an option on the newly added rule is passed correctly to the RuleCollection
+            # we try this with all different rule qualifiers to ensure they all are normalized and map
+            # to the same rule
+            for other_rule_qualifier in rule_qualifiers:
+                cb = config_builder.clone()
+                cb.set_option(other_rule_qualifier, "regex", other_rule_qualifier + "bōr")
+                # before setting the expected rule option value correctly, the RuleCollection should be different
+                self.assertNotEqual(cb.build().rules, expected_rules)
+                # after setting the option on the expected rule, it should be equal
+                my_rule.options["regex"].set(other_rule_qualifier + "bōr")
+                self.assertEqual(cb.build().rules, expected_rules)
+                my_rule.options["regex"].set("wrong")
+
+    def test_named_rules_negative(self):
+        # Invalid rule name (T7 = title-match-regex)
+        for invalid_name in ["", " ", "    ", "\t", "\n", "å b", "å:b", "åb:", ":åb"]:
+            config_builder = LintConfigBuilder()
+            config_builder.set_option(f"T7:{invalid_name}", "regex", "tëst")
+            expected_msg = f"The rule-name part in 'T7:{invalid_name}' cannot contain whitespace, colons or be empty"
+            with self.assertRaisesMessage(LintConfigError, expected_msg):
+                config_builder.build()
+
+        # Invalid parent rule name
+        config_builder = LintConfigBuilder()
+        config_builder.set_option("Ž123:foöbar", "fåke-option", "fåke-value")
+        with self.assertRaisesMessage(LintConfigError, "No such rule 'Ž123' (named rule: 'Ž123:foöbar')"):
+            config_builder.build()
+
+        # Invalid option name (this is the same as with regular rules)
+        config_builder = LintConfigBuilder()
+        config_builder.set_option("T7:foöbar", "blå", "my-rëgex")
+        with self.assertRaisesMessage(LintConfigError, "Rule 'T7:foöbar' has no option 'blå'"):
+            config_builder.build()
diff --git a/gitlint-core/gitlint/tests/config/test_config_precedence.py b/gitlint-core/gitlint/tests/config/test_config_precedence.py
new file mode 100644
index 0000000..a7f94cf
--- /dev/null
+++ b/gitlint-core/gitlint/tests/config/test_config_precedence.py
@@ -0,0 +1,98 @@
+from io import StringIO
+from unittest.mock import patch
+
+from click.testing import CliRunner
+from gitlint import cli
+from gitlint.config import LintConfigBuilder
+from gitlint.tests.base import BaseTestCase
+
+
+class LintConfigPrecedenceTests(BaseTestCase):
+    def setUp(self):
+        super().setUp()
+        self.cli = CliRunner()
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP:fö\n\nThis is å test message\n")
+    def test_config_precedence(self, _):
+        # TODO(jroovers): this test really only test verbosity, we need to do some refactoring to gitlint.cli
+        # to more easily test everything
+        # Test that the config precedence is followed:
+        # 1. commandline convenience flags
+        # 2. environment variables
+        # 3. commandline -c flags
+        # 4. config file
+        # 5. default config
+        config_path = self.get_sample_path("config/gitlintconfig")
+
+        # 1. commandline convenience flags
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["-vvv", "-c", "general.verbosity=2", "--config", config_path])
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5 Title contains the word 'WIP' (case-insensitive): \"WIP:fö\"\n")
+
+        # 2. environment variables
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(
+                cli.cli, ["-c", "general.verbosity=2", "--config", config_path], env={"GITLINT_VERBOSITY": "3"}
+            )
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5 Title contains the word 'WIP' (case-insensitive): \"WIP:fö\"\n")
+
+        # 3. commandline -c flags
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["-c", "general.verbosity=2", "--config", config_path])
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5 Title contains the word 'WIP' (case-insensitive)\n")
+
+        # 4. config file
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli, ["--config", config_path])
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5\n")
+
+        # 5. default config
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            result = self.cli.invoke(cli.cli)
+            self.assertEqual(result.output, "")
+            self.assertEqual(stderr.getvalue(), "1: T5 Title contains the word 'WIP' (case-insensitive): \"WIP:fö\"\n")
+
+    @patch("gitlint.cli.get_stdin_data", return_value="WIP: This is å test")
+    def test_ignore_precedence(self, get_stdin_data):
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            # --ignore takes precedence over -c general.ignore
+            result = self.cli.invoke(cli.cli, ["-c", "general.ignore=T5", "--ignore", "B6"])
+            self.assertEqual(result.output, "")
+            self.assertEqual(result.exit_code, 1)
+            # We still expect the T5 violation, but no B6 violation as --ignore overwrites -c general.ignore
+            self.assertEqual(
+                stderr.getvalue(), "1: T5 Title contains the word 'WIP' (case-insensitive): \"WIP: This is å test\"\n"
+            )
+
+        # test that we can also still configure a rule that is first ignored but then not
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            get_stdin_data.return_value = "This is å test"
+            # --ignore takes precedence over -c general.ignore
+            result = self.cli.invoke(
+                cli.cli,
+                ["-c", "general.ignore=title-max-length", "-c", "title-max-length.line-length=5", "--ignore", "B6"],
+            )
+            self.assertEqual(result.output, "")
+            self.assertEqual(result.exit_code, 1)
+
+            # We still expect the T1 violation with custom config,
+            # but no B6 violation as --ignore overwrites -c general.ignore
+            self.assertEqual(stderr.getvalue(), '1: T1 Title exceeds max length (14>5): "This is å test"\n')
+
+    def test_general_option_after_rule_option(self):
+        # We used to have a bug where we didn't process general options before setting specific options, this would
+        # lead to errors when e.g.: trying to configure a user rule before the rule class was loaded by extra-path
+        # This test is here to test for regressions against this.
+
+        config_builder = LintConfigBuilder()
+        config_builder.set_option("my-üser-commit-rule", "violation-count", 3)
+        user_rules_path = self.get_sample_path("user_rules")
+        config_builder.set_option("general", "extra-path", user_rules_path)
+        config = config_builder.build()
+
+        self.assertEqual(config.extra_path, user_rules_path)
+        self.assertEqual(config.get_rule_option("my-üser-commit-rule", "violation-count"), 3)
diff --git a/gitlint-core/gitlint/tests/config/test_rule_collection.py b/gitlint-core/gitlint/tests/config/test_rule_collection.py
new file mode 100644
index 0000000..2cb0e5c
--- /dev/null
+++ b/gitlint-core/gitlint/tests/config/test_rule_collection.py
@@ -0,0 +1,62 @@
+from collections import OrderedDict
+
+from gitlint import rules
+from gitlint.config import RuleCollection
+from gitlint.tests.base import BaseTestCase
+
+
+class RuleCollectionTests(BaseTestCase):
+    def test_add_rule(self):
+        collection = RuleCollection()
+        collection.add_rule(rules.TitleMaxLength, "my-rüle", {"my_attr": "föo", "my_attr2": 123})
+
+        expected = rules.TitleMaxLength()
+        expected.id = "my-rüle"
+        expected.my_attr = "föo"
+        expected.my_attr2 = 123
+
+        self.assertEqual(len(collection), 1)
+        self.assertDictEqual(collection._rules, OrderedDict({"my-rüle": expected}))
+        # Need to explicitly compare expected attributes as the rule.__eq__ method does not compare these attributes
+        self.assertEqual(collection._rules[expected.id].my_attr, expected.my_attr)
+        self.assertEqual(collection._rules[expected.id].my_attr2, expected.my_attr2)
+
+    def test_add_find_rule(self):
+        collection = RuleCollection()
+        collection.add_rules([rules.TitleMaxLength, rules.TitleTrailingWhitespace], {"my_attr": "föo"})
+
+        # find by id
+        expected = rules.TitleMaxLength()
+        rule = collection.find_rule("T1")
+        self.assertEqual(rule, expected)
+        self.assertEqual(rule.my_attr, "föo")
+
+        # find by name
+        expected2 = rules.TitleTrailingWhitespace()
+        rule = collection.find_rule("title-trailing-whitespace")
+        self.assertEqual(rule, expected2)
+        self.assertEqual(rule.my_attr, "föo")
+
+        # find non-existing
+        rule = collection.find_rule("föo")
+        self.assertIsNone(rule)
+
+    def test_delete_rules_by_attr(self):
+        collection = RuleCollection()
+        collection.add_rules([rules.TitleMaxLength, rules.TitleTrailingWhitespace], {"foo": "bår"})
+        collection.add_rules([rules.BodyHardTab], {"hur": "dûr"})
+
+        # Assert all rules are there as expected
+        self.assertEqual(len(collection), 3)
+        for expected_rule in [rules.TitleMaxLength(), rules.TitleTrailingWhitespace(), rules.BodyHardTab()]:
+            self.assertEqual(collection.find_rule(expected_rule.id), expected_rule)
+
+        # Delete rules by attr, assert that we still have the right rules in the collection
+        collection.delete_rules_by_attr("foo", "bår")
+        self.assertEqual(len(collection), 1)
+        self.assertIsNone(collection.find_rule(rules.TitleMaxLength.id), None)
+        self.assertIsNone(collection.find_rule(rules.TitleTrailingWhitespace.id), None)
+
+        found = collection.find_rule(rules.BodyHardTab.id)
+        self.assertEqual(found, rules.BodyHardTab())
+        self.assertEqual(found.hur, "dûr")
diff --git a/gitlint-core/gitlint/tests/contrib/__init__.py b/gitlint-core/gitlint/tests/contrib/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/gitlint-core/gitlint/tests/contrib/rules/__init__.py b/gitlint-core/gitlint/tests/contrib/rules/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py b/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py
new file mode 100644
index 0000000..2bad2ed
--- /dev/null
+++ b/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py
@@ -0,0 +1,105 @@
+from collections import namedtuple
+from unittest.mock import patch
+
+from gitlint.config import LintConfig
+from gitlint.contrib.rules.authors_commit import AllowedAuthors
+from gitlint.rules import RuleViolation
+from gitlint.tests.base import BaseTestCase
+
+
+class ContribAuthorsCommitTests(BaseTestCase):
+    def setUp(self):
+        author = namedtuple("Author", "name, email")
+        self.author_1 = author("John Doe", "john.doe@mail.com")
+        self.author_2 = author("Bob Smith", "bob.smith@mail.com")
+        self.rule = AllowedAuthors()
+        self.gitcontext = self.get_gitcontext()
+
+    def get_gitcontext(self):
+        gitcontext = self.gitcontext(self.get_sample("commit_message/sample1"))
+        gitcontext.repository_path = self.get_sample_path("config")
+        return gitcontext
+
+    def get_commit(self, name, email):
+        commit = self.gitcommit("commit_message/sample1", author_name=name, author_email=email)
+        commit.message.context = self.gitcontext
+        return commit
+
+    def test_enable(self):
+        for rule_ref in ["CC3", "contrib-allowed-authors"]:
+            config = LintConfig()
+            config.contrib = [rule_ref]
+            self.assertIn(AllowedAuthors(), config.rules)
+
+    def test_authors_succeeds(self):
+        for author in [self.author_1, self.author_2]:
+            commit = self.get_commit(author.name, author.email)
+            violations = self.rule.validate(commit)
+            self.assertListEqual([], violations)
+
+    def test_authors_email_is_case_insensitive(self):
+        for email in [
+            self.author_2.email.capitalize(),
+            self.author_2.email.lower(),
+            self.author_2.email.upper(),
+        ]:
+            commit = self.get_commit(self.author_2.name, email)
+            violations = self.rule.validate(commit)
+            self.assertListEqual([], violations)
+
+    def test_authors_name_is_case_sensitive(self):
+        for name in [self.author_2.name.lower(), self.author_2.name.upper()]:
+            commit = self.get_commit(name, self.author_2.email)
+            violations = self.rule.validate(commit)
+            expected_violation = RuleViolation(
+                "CC3",
+                f"Author not in 'AUTHORS' file: " f'"{name} <{self.author_2.email}>"',
+            )
+            self.assertListEqual([expected_violation], violations)
+
+    def test_authors_bad_name_fails(self):
+        for name in ["", "root"]:
+            commit = self.get_commit(name, self.author_2.email)
+            violations = self.rule.validate(commit)
+            expected_violation = RuleViolation(
+                "CC3",
+                f"Author not in 'AUTHORS' file: " f'"{name} <{self.author_2.email}>"',
+            )
+            self.assertListEqual([expected_violation], violations)
+
+    def test_authors_bad_email_fails(self):
+        for email in ["", "root@example.com"]:
+            commit = self.get_commit(self.author_2.name, email)
+            violations = self.rule.validate(commit)
+            expected_violation = RuleViolation(
+                "CC3",
+                f"Author not in 'AUTHORS' file: " f'"{self.author_2.name} <{email}>"',
+            )
+            self.assertListEqual([expected_violation], violations)
+
+    def test_authors_invalid_combination_fails(self):
+        commit = self.get_commit(self.author_1.name, self.author_2.email)
+        violations = self.rule.validate(commit)
+        expected_violation = RuleViolation(
+            "CC3",
+            f"Author not in 'AUTHORS' file: " f'"{self.author_1.name} <{self.author_2.email}>"',
+        )
+        self.assertListEqual([expected_violation], violations)
+
+    @patch(
+        "gitlint.contrib.rules.authors_commit.Path.read_text",
+        return_value="John Doe <john.doe@mail.com>",
+    )
+    def test_read_authors_file(self, _mock_read_text):
+        authors, authors_file_name = AllowedAuthors._read_authors_from_file(self.gitcontext)
+        self.assertEqual(authors_file_name, "AUTHORS")
+        self.assertEqual(len(authors), 1)
+        self.assertEqual(authors, {self.author_1})
+
+    @patch(
+        "gitlint.contrib.rules.authors_commit.Path.exists",
+        return_value=False,
+    )
+    def test_read_authors_file_missing_file(self, _mock_iterdir):
+        with self.assertRaisesMessage(FileNotFoundError, "No AUTHORS file found!"):
+            AllowedAuthors._read_authors_from_file(self.gitcontext)
diff --git a/gitlint-core/gitlint/tests/contrib/rules/test_conventional_commit.py b/gitlint-core/gitlint/tests/contrib/rules/test_conventional_commit.py
new file mode 100644
index 0000000..cbab684
--- /dev/null
+++ b/gitlint-core/gitlint/tests/contrib/rules/test_conventional_commit.py
@@ -0,0 +1,82 @@
+from gitlint.config import LintConfig
+from gitlint.contrib.rules.conventional_commit import ConventionalCommit
+from gitlint.rules import RuleViolation
+from gitlint.tests.base import BaseTestCase
+
+
+class ContribConventionalCommitTests(BaseTestCase):
+    def test_enable(self):
+        # Test that rule can be enabled in config
+        for rule_ref in ["CT1", "contrib-title-conventional-commits"]:
+            config = LintConfig()
+            config.contrib = [rule_ref]
+            self.assertIn(ConventionalCommit(), config.rules)
+
+    def test_conventional_commits(self):
+        rule = ConventionalCommit()
+
+        # No violations when using a correct type and format
+        for type in ["fix", "feat", "chore", "docs", "style", "refactor", "perf", "test", "revert", "ci", "build"]:
+            violations = rule.validate(type + ": föo", None)
+            self.assertListEqual([], violations)
+
+        # assert violation on wrong type
+        expected_violation = RuleViolation(
+            "CT1",
+            "Title does not start with one of fix, feat, chore, docs, style, refactor, perf, test, revert, ci, build",
+            "bår: foo",
+        )
+        violations = rule.validate("bår: foo", None)
+        self.assertListEqual([expected_violation], violations)
+
+        # assert violation when use strange chars after correct type
+        expected_violation = RuleViolation(
+            "CT1",
+            "Title does not start with one of fix, feat, chore, docs, style, refactor, perf, test, revert, ci, build",
+            "feat_wrong_chars: föo",
+        )
+        violations = rule.validate("feat_wrong_chars: föo", None)
+        self.assertListEqual([expected_violation], violations)
+
+        # assert violation when use strange chars after correct type
+        expected_violation = RuleViolation(
+            "CT1",
+            "Title does not start with one of fix, feat, chore, docs, style, refactor, perf, test, revert, ci, build",
+            "feat_wrong_chars(scope): föo",
+        )
+        violations = rule.validate("feat_wrong_chars(scope): föo", None)
+        self.assertListEqual([expected_violation], violations)
+
+        # assert violation on wrong format
+        expected_violation = RuleViolation(
+            "CT1",
+            "Title does not follow ConventionalCommits.org format 'type(optional-scope): description'",
+            "fix föo",
+        )
+        violations = rule.validate("fix föo", None)
+        self.assertListEqual([expected_violation], violations)
+
+        # assert no violation when use ! for breaking changes without scope
+        violations = rule.validate("feat!: föo", None)
+        self.assertListEqual([], violations)
+
+        # assert no violation when use ! for breaking changes with scope
+        violations = rule.validate("fix(scope)!: föo", None)
+        self.assertListEqual([], violations)
+
+        # assert no violation when adding new type
+        rule = ConventionalCommit({"types": ["föo", "bär"]})
+        for typ in ["föo", "bär"]:
+            violations = rule.validate(typ + ": hür dur", None)
+            self.assertListEqual([], violations)
+
+        # assert violation when using incorrect type when types have been reconfigured
+        violations = rule.validate("fix: hür dur", None)
+        expected_violation = RuleViolation("CT1", "Title does not start with one of föo, bär", "fix: hür dur")
+        self.assertListEqual([expected_violation], violations)
+
+        # assert no violation when adding new type named with numbers
+        rule = ConventionalCommit({"types": ["föo123", "123bär"]})
+        for typ in ["föo123", "123bär"]:
+            violations = rule.validate(typ + ": hür dur", None)
+            self.assertListEqual([], violations)
diff --git a/gitlint-core/gitlint/tests/contrib/rules/test_disallow_cleanup_commits.py b/gitlint-core/gitlint/tests/contrib/rules/test_disallow_cleanup_commits.py
new file mode 100644
index 0000000..1983367
--- /dev/null
+++ b/gitlint-core/gitlint/tests/contrib/rules/test_disallow_cleanup_commits.py
@@ -0,0 +1,34 @@
+from gitlint.config import LintConfig
+from gitlint.contrib.rules.disallow_cleanup_commits import DisallowCleanupCommits
+from gitlint.rules import RuleViolation
+from gitlint.tests.base import BaseTestCase
+
+
+class ContribDisallowCleanupCommitsTest(BaseTestCase):
+    def test_enable(self):
+        # Test that rule can be enabled in config
+        for rule_ref in ["CC2", "contrib-disallow-cleanup-commits"]:
+            config = LintConfig()
+            config.contrib = [rule_ref]
+            self.assertIn(DisallowCleanupCommits(), config.rules)
+
+    def test_disallow_fixup_squash_commit(self):
+        # No violations when no 'fixup!' line and no 'squash!' line is present
+        rule = DisallowCleanupCommits()
+        violations = rule.validate(self.gitcommit("Föobar\n\nMy Body"))
+        self.assertListEqual(violations, [])
+
+        # Assert violation when 'fixup!' in title
+        violations = rule.validate(self.gitcommit("fixup! Föobar\n\nMy Body"))
+        expected_violation = RuleViolation("CC2", "Fixup commits are not allowed", line_nr=1)
+        self.assertListEqual(violations, [expected_violation])
+
+        # Assert violation when 'squash!' in title
+        violations = rule.validate(self.gitcommit("squash! Föobar\n\nMy Body"))
+        expected_violation = RuleViolation("CC2", "Squash commits are not allowed", line_nr=1)
+        self.assertListEqual(violations, [expected_violation])
+
+        # Assert violation when 'amend!' in title
+        violations = rule.validate(self.gitcommit("amend! Föobar\n\nMy Body"))
+        expected_violation = RuleViolation("CC2", "Amend commits are not allowed", line_nr=1)
+        self.assertListEqual(violations, [expected_violation])
diff --git a/gitlint-core/gitlint/tests/contrib/rules/test_signedoff_by.py b/gitlint-core/gitlint/tests/contrib/rules/test_signedoff_by.py
new file mode 100644
index 0000000..bf526a0
--- /dev/null
+++ b/gitlint-core/gitlint/tests/contrib/rules/test_signedoff_by.py
@@ -0,0 +1,28 @@
+from gitlint.config import LintConfig
+from gitlint.contrib.rules.signedoff_by import SignedOffBy
+from gitlint.rules import RuleViolation
+from gitlint.tests.base import BaseTestCase
+
+
+class ContribSignedOffByTests(BaseTestCase):
+    def test_enable(self):
+        # Test that rule can be enabled in config
+        for rule_ref in ["CC1", "contrib-body-requires-signed-off-by"]:
+            config = LintConfig()
+            config.contrib = [rule_ref]
+            self.assertIn(SignedOffBy(), config.rules)
+
+    def test_signedoff_by(self):
+        # No violations when 'Signed-off-by' line is present
+        rule = SignedOffBy()
+        violations = rule.validate(self.gitcommit("Föobar\n\nMy Body\nSigned-off-by: John Smith"))
+        self.assertListEqual([], violations)
+
+        # Assert violation when no 'Signed-off-by' line is present
+        violations = rule.validate(self.gitcommit("Föobar\n\nMy Body"))
+        expected_violation = RuleViolation("CC1", "Body does not contain a 'Signed-off-by' line", line_nr=1)
+        self.assertListEqual(violations, [expected_violation])
+
+        # Assert violation when no 'Signed-off-by' in title but not in body
+        violations = rule.validate(self.gitcommit("Signed-off-by\n\nFöobar"))
+        self.assertListEqual(violations, [expected_violation])
diff --git a/gitlint-core/gitlint/tests/contrib/test_contrib_rules.py b/gitlint-core/gitlint/tests/contrib/test_contrib_rules.py
new file mode 100644
index 0000000..b0372d8
--- /dev/null
+++ b/gitlint-core/gitlint/tests/contrib/test_contrib_rules.py
@@ -0,0 +1,69 @@
+import os
+
+from gitlint import rule_finder, rules
+from gitlint.contrib import rules as contrib_rules
+from gitlint.tests.base import BaseTestCase
+from gitlint.tests.contrib import rules as contrib_tests
+
+
+class ContribRuleTests(BaseTestCase):
+    CONTRIB_DIR = os.path.dirname(os.path.realpath(contrib_rules.__file__))
+
+    def test_contrib_tests_exist(self):
+        """Tests that every contrib rule file has an associated test file.
+        While this doesn't guarantee that every contrib rule has associated tests (as we don't check the content
+        of the tests file), it's a good leading indicator."""
+
+        contrib_tests_dir = os.path.dirname(os.path.realpath(contrib_tests.__file__))
+        contrib_test_files = os.listdir(contrib_tests_dir)
+
+        # Find all python files in the contrib dir and assert there's a corresponding test file
+        for filename in os.listdir(self.CONTRIB_DIR):
+            if filename.endswith(".py") and filename not in ["__init__.py"]:
+                expected_test_file = f"test_{filename}"
+                error_msg = (
+                    "Every Contrib Rule must have associated tests. "
+                    f"Expected test file {os.path.join(contrib_tests_dir, expected_test_file)} not found."
+                )
+                self.assertIn(expected_test_file, contrib_test_files, error_msg)
+
+    def test_contrib_rule_naming_conventions(self):
+        """Tests that contrib rules follow certain naming conventions.
+        We can test for this at test time (and not during runtime like rule_finder.assert_valid_rule_class does)
+        because these are contrib rules: once they're part of gitlint they can't change unless they pass this test
+        again.
+        """
+        rule_classes = rule_finder.find_rule_classes(self.CONTRIB_DIR)
+
+        for clazz in rule_classes:
+            # Contrib rule names start with "contrib-"
+            self.assertTrue(clazz.name.startswith("contrib-"))
+
+            # Contrib line rules id's start with "CL"
+            if issubclass(clazz, rules.LineRule):
+                if clazz.target == rules.CommitMessageTitle:
+                    self.assertTrue(clazz.id.startswith("CT"))
+                elif clazz.target == rules.CommitMessageBody:
+                    self.assertTrue(clazz.id.startswith("CB"))
+
+    def test_contrib_rule_uniqueness(self):
+        """Tests that all contrib rules have unique identifiers.
+        We can test for this at test time (and not during runtime like rule_finder.assert_valid_rule_class does)
+        because these are contrib rules: once they're part of gitlint they can't change unless they pass this test
+        again.
+        """
+        rule_classes = rule_finder.find_rule_classes(self.CONTRIB_DIR)
+
+        # Not very efficient way of checking uniqueness, but it works :-)
+        class_names = [rule_class.name for rule_class in rule_classes]
+        class_ids = [rule_class.id for rule_class in rule_classes]
+        self.assertEqual(len(set(class_names)), len(class_names))
+        self.assertEqual(len(set(class_ids)), len(class_ids))
+
+    def test_contrib_rule_instantiated(self):
+        """Tests that all contrib rules can be instantiated without errors."""
+        rule_classes = rule_finder.find_rule_classes(self.CONTRIB_DIR)
+
+        # No exceptions = what we want :-)
+        for rule_class in rule_classes:
+            rule_class()
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_contrib_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_contrib_1
new file mode 100644
index 0000000..b95433b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_contrib_1
@@ -0,0 +1,2 @@
+1: CC1 Body does not contain a 'Signed-off-by' line
+1: CT1 Title does not follow ConventionalCommits.org format 'type(optional-scope): description': "Test tïtle"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_debug_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_debug_1
new file mode 100644
index 0000000..046294c
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_debug_1
@@ -0,0 +1,139 @@
+DEBUG: gitlint.cli To report issues, please visit https://github.com/jorisroovers/gitlint/issues
+DEBUG: gitlint.cli Platform: {platform}
+DEBUG: gitlint.cli Python version: {python_version}
+DEBUG: gitlint.cli Git version: git version 1.2.3
+DEBUG: gitlint.cli Gitlint version: {gitlint_version}
+DEBUG: gitlint.cli GITLINT_USE_SH_LIB: {GITLINT_USE_SH_LIB}
+DEBUG: gitlint.cli TERMINAL_ENCODING: {TERMINAL_ENCODING}
+DEBUG: gitlint.cli FILE_ENCODING: {FILE_ENCODING}
+DEBUG: gitlint.cli Configuration
+config-path: {config_path}
+[GENERAL]
+extra-path: None
+contrib: []
+ignore: title-trailing-whitespace,B2
+ignore-merge-commits: False
+ignore-fixup-commits: True
+ignore-fixup-amend-commits: True
+ignore-squash-commits: True
+ignore-revert-commits: True
+ignore-stdin: False
+staged: False
+fail-without-commits: False
+regex-style-search: False
+verbosity: 1
+debug: True
+target: {target}
+[RULES]
+  I1: ignore-by-title
+     ignore=all
+     regex=None
+  I2: ignore-by-body
+     ignore=all
+     regex=None
+  I3: ignore-body-lines
+     regex=None
+  I4: ignore-by-author-name
+     ignore=all
+     regex=None
+  T1: title-max-length
+     line-length=20
+  T2: title-trailing-whitespace
+  T6: title-leading-whitespace
+  T3: title-trailing-punctuation
+  T4: title-hard-tab
+  T5: title-must-not-contain-word
+     words=WIP,bögus
+  T7: title-match-regex
+     regex=None
+  T8: title-min-length
+     min-length=5
+  B1: body-max-line-length
+     line-length=30
+  B5: body-min-length
+     min-length=20
+  B6: body-is-missing
+     ignore-merge-commits=True
+  B2: body-trailing-whitespace
+  B3: body-hard-tab
+  B4: body-first-line-empty
+  B7: body-changed-file-mention
+     files=
+  B8: body-match-regex
+     regex=None
+  M1: author-valid-email
+     regex=^[^@ ]+@[^@ ]+\.[^@ ]+
+
+DEBUG: gitlint.cli No --msg-filename flag, no or empty data passed to stdin. Using the local repo.
+DEBUG: gitlint.git ('rev-list', 'foo...bar')
+DEBUG: gitlint.cli Linting 3 commit(s)
+DEBUG: gitlint.git ('log', '6f29bf81a8322a04071bb794666e48c443a90360', '-1', '--pretty=%aN%x00%aE%x00%ai%x00%P%n%B')
+DEBUG: gitlint.git ('config', '--get', 'core.commentchar')
+DEBUG: gitlint.lint Linting commit 6f29bf81a8322a04071bb794666e48c443a90360
+DEBUG: gitlint.git ('diff-tree', '--no-commit-id', '--numstat', '-r', '--root', '6f29bf81a8322a04071bb794666e48c443a90360')
+DEBUG: gitlint.git ('branch', '--contains', '6f29bf81a8322a04071bb794666e48c443a90360')
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+commït-title1
+
+commït-body1
+--- Meta info ---------
+Author: test åuthor1 <test-email1@föo.com>
+Date:   2016-12-03 15:28:15 +0100
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: ['a123']
+Branches: ['commit-1-branch-1', 'commit-1-branch-2']
+Changed Files: ['commit-1/file-1', 'commit-1/file-2']
+Changed Files Stats:
+{changed_files_stats1}
+-----------------------
+DEBUG: gitlint.git ('log', '25053ccec5e28e1bb8f7551fdbb5ab213ada2401', '-1', '--pretty=%aN%x00%aE%x00%ai%x00%P%n%B')
+DEBUG: gitlint.lint Linting commit 25053ccec5e28e1bb8f7551fdbb5ab213ada2401
+DEBUG: gitlint.git ('diff-tree', '--no-commit-id', '--numstat', '-r', '--root', '25053ccec5e28e1bb8f7551fdbb5ab213ada2401')
+DEBUG: gitlint.git ('branch', '--contains', '25053ccec5e28e1bb8f7551fdbb5ab213ada2401')
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+commït-title2.
+
+commït-body2
+--- Meta info ---------
+Author: test åuthor2 <test-email2@föo.com>
+Date:   2016-12-04 15:28:15 +0100
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: ['b123']
+Branches: ['commit-2-branch-1', 'commit-2-branch-2']
+Changed Files: ['commit-2/file-1', 'commit-2/file-2']
+Changed Files Stats:
+{changed_files_stats2}
+-----------------------
+DEBUG: gitlint.git ('log', '4da2656b0dadc76c7ee3fd0243a96cb64007f125', '-1', '--pretty=%aN%x00%aE%x00%ai%x00%P%n%B')
+DEBUG: gitlint.lint Linting commit 4da2656b0dadc76c7ee3fd0243a96cb64007f125
+DEBUG: gitlint.git ('diff-tree', '--no-commit-id', '--numstat', '-r', '--root', '4da2656b0dadc76c7ee3fd0243a96cb64007f125')
+DEBUG: gitlint.git ('branch', '--contains', '4da2656b0dadc76c7ee3fd0243a96cb64007f125')
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+föobar
+bar
+--- Meta info ---------
+Author: test åuthor3 <test-email3@föo.com>
+Date:   2016-12-05 15:28:15 +0100
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: ['c123']
+Branches: ['commit-3-branch-1', 'commit-3-branch-2']
+Changed Files: ['commit-3/file-1', 'commit-3/file-2']
+Changed Files Stats:
+{changed_files_stats3}
+-----------------------
+DEBUG: gitlint.cli Exit Code = 6
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_1
new file mode 100644
index 0000000..4326729
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_1
@@ -0,0 +1,3 @@
+1: T2 Title has trailing whitespace: "WIP: tïtle "
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: tïtle "
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_1
new file mode 100644
index 0000000..4326729
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_1
@@ -0,0 +1,3 @@
+1: T2 Title has trailing whitespace: "WIP: tïtle "
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: tïtle "
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_2 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_2
new file mode 100644
index 0000000..46a8adf
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_input_stream_debug_2
@@ -0,0 +1,89 @@
+DEBUG: gitlint.cli To report issues, please visit https://github.com/jorisroovers/gitlint/issues
+DEBUG: gitlint.cli Platform: {platform}
+DEBUG: gitlint.cli Python version: {python_version}
+DEBUG: gitlint.cli Git version: git version 1.2.3
+DEBUG: gitlint.cli Gitlint version: {gitlint_version}
+DEBUG: gitlint.cli GITLINT_USE_SH_LIB: {GITLINT_USE_SH_LIB}
+DEBUG: gitlint.cli TERMINAL_ENCODING: {TERMINAL_ENCODING}
+DEBUG: gitlint.cli FILE_ENCODING: {FILE_ENCODING}
+DEBUG: gitlint.cli Configuration
+config-path: None
+[GENERAL]
+extra-path: None
+contrib: []
+ignore: 
+ignore-merge-commits: True
+ignore-fixup-commits: True
+ignore-fixup-amend-commits: True
+ignore-squash-commits: True
+ignore-revert-commits: True
+ignore-stdin: False
+staged: False
+fail-without-commits: False
+regex-style-search: False
+verbosity: 3
+debug: True
+target: {target}
+[RULES]
+  I1: ignore-by-title
+     ignore=all
+     regex=None
+  I2: ignore-by-body
+     ignore=all
+     regex=None
+  I3: ignore-body-lines
+     regex=None
+  I4: ignore-by-author-name
+     ignore=all
+     regex=None
+  T1: title-max-length
+     line-length=72
+  T2: title-trailing-whitespace
+  T6: title-leading-whitespace
+  T3: title-trailing-punctuation
+  T4: title-hard-tab
+  T5: title-must-not-contain-word
+     words=WIP
+  T7: title-match-regex
+     regex=None
+  T8: title-min-length
+     min-length=5
+  B1: body-max-line-length
+     line-length=80
+  B5: body-min-length
+     min-length=20
+  B6: body-is-missing
+     ignore-merge-commits=True
+  B2: body-trailing-whitespace
+  B3: body-hard-tab
+  B4: body-first-line-empty
+  B7: body-changed-file-mention
+     files=
+  B8: body-match-regex
+     regex=None
+  M1: author-valid-email
+     regex=^[^@ ]+@[^@ ]+\.[^@ ]+
+
+DEBUG: gitlint.cli Stdin data: 'WIP: tïtle 
+'
+DEBUG: gitlint.cli Stdin detected and not ignored. Using as input.
+DEBUG: gitlint.git ('config', '--get', 'core.commentchar')
+DEBUG: gitlint.cli Linting 1 commit(s)
+DEBUG: gitlint.lint Linting commit [SHA UNKNOWN]
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+WIP: tïtle 
+--- Meta info ---------
+Author: None <None>
+Date:   None
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: []
+Branches: []
+Changed Files: []
+Changed Files Stats: {{}}
+-----------------------
+DEBUG: gitlint.cli Exit Code = 3
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_commit_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_commit_1
new file mode 100644
index 0000000..b9f0742
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_commit_1
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: commït-title1"
+3: B5 Body message is too short (12<20): "commït-body1"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_1
new file mode 100644
index 0000000..be3288b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_1
@@ -0,0 +1,8 @@
+Commit 6f29bf81a8:
+3: B5 Body message is too short (12<20): "commït-body1"
+
+Commit 25053ccec5:
+3: B5 Body message is too short (12<20): "commït-body2"
+
+Commit 4da2656b0d:
+3: B5 Body message is too short (12<20): "commït-body3"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_config_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_config_1
new file mode 100644
index 0000000..1bf0503
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_config_1
@@ -0,0 +1,6 @@
+Commit 6f29bf81a8:
+3: B5 Body message is too short (12<20): "commït-body1"
+
+Commit 4da2656b0d:
+1: T3 Title has trailing punctuation (.): "commït-title3."
+3: B5 Body message is too short (12<20): "commït-body3"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_csv_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_csv_1
new file mode 100644
index 0000000..be3288b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_multiple_commits_csv_1
@@ -0,0 +1,8 @@
+Commit 6f29bf81a8:
+3: B5 Body message is too short (12<20): "commït-body1"
+
+Commit 25053ccec5:
+3: B5 Body message is too short (12<20): "commït-body2"
+
+Commit 4da2656b0d:
+3: B5 Body message is too short (12<20): "commït-body3"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_1
new file mode 100644
index 0000000..9a9091b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_1
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: msg-filename tïtle"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_2 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_2
new file mode 100644
index 0000000..6b96a45
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_msg_filename_2
@@ -0,0 +1,93 @@
+DEBUG: gitlint.cli To report issues, please visit https://github.com/jorisroovers/gitlint/issues
+DEBUG: gitlint.cli Platform: {platform}
+DEBUG: gitlint.cli Python version: {python_version}
+DEBUG: gitlint.cli Git version: git version 1.2.3
+DEBUG: gitlint.cli Gitlint version: {gitlint_version}
+DEBUG: gitlint.cli GITLINT_USE_SH_LIB: {GITLINT_USE_SH_LIB}
+DEBUG: gitlint.cli TERMINAL_ENCODING: {TERMINAL_ENCODING}
+DEBUG: gitlint.cli FILE_ENCODING: {FILE_ENCODING}
+DEBUG: gitlint.cli Configuration
+config-path: None
+[GENERAL]
+extra-path: None
+contrib: []
+ignore: 
+ignore-merge-commits: True
+ignore-fixup-commits: True
+ignore-fixup-amend-commits: True
+ignore-squash-commits: True
+ignore-revert-commits: True
+ignore-stdin: False
+staged: True
+fail-without-commits: False
+regex-style-search: False
+verbosity: 3
+debug: True
+target: {target}
+[RULES]
+  I1: ignore-by-title
+     ignore=all
+     regex=None
+  I2: ignore-by-body
+     ignore=all
+     regex=None
+  I3: ignore-body-lines
+     regex=None
+  I4: ignore-by-author-name
+     ignore=all
+     regex=None
+  T1: title-max-length
+     line-length=72
+  T2: title-trailing-whitespace
+  T6: title-leading-whitespace
+  T3: title-trailing-punctuation
+  T4: title-hard-tab
+  T5: title-must-not-contain-word
+     words=WIP
+  T7: title-match-regex
+     regex=None
+  T8: title-min-length
+     min-length=5
+  B1: body-max-line-length
+     line-length=80
+  B5: body-min-length
+     min-length=20
+  B6: body-is-missing
+     ignore-merge-commits=True
+  B2: body-trailing-whitespace
+  B3: body-hard-tab
+  B4: body-first-line-empty
+  B7: body-changed-file-mention
+     files=
+  B8: body-match-regex
+     regex=None
+  M1: author-valid-email
+     regex=^[^@ ]+@[^@ ]+\.[^@ ]+
+
+DEBUG: gitlint.cli Fetching additional meta-data from staged commit
+DEBUG: gitlint.cli Using --msg-filename.
+DEBUG: gitlint.git ('config', '--get', 'core.commentchar')
+DEBUG: gitlint.cli Linting 1 commit(s)
+DEBUG: gitlint.lint Linting commit [SHA UNKNOWN]
+DEBUG: gitlint.git ('diff', '--staged', '--numstat', '-r')
+DEBUG: gitlint.git ('config', '--get', 'user.name')
+DEBUG: gitlint.git ('config', '--get', 'user.email')
+DEBUG: gitlint.git ('rev-parse', '--abbrev-ref', 'HEAD')
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+WIP: msg-filename tïtle
+--- Meta info ---------
+Author: föo user <föo@bar.com>
+Date:   2020-02-19 12:18:46 +0100
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: []
+Branches: ['my-branch']
+Changed Files: ['commit-1/file-1', 'commit-1/file-2']
+Changed Files Stats:
+{changed_files_stats}
+-----------------------
+DEBUG: gitlint.cli Exit Code = 2
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_1
new file mode 100644
index 0000000..4326729
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_1
@@ -0,0 +1,3 @@
+1: T2 Title has trailing whitespace: "WIP: tïtle "
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: tïtle "
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_2 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_2
new file mode 100644
index 0000000..45d94e2
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_lint_staged_stdin_2
@@ -0,0 +1,95 @@
+DEBUG: gitlint.cli To report issues, please visit https://github.com/jorisroovers/gitlint/issues
+DEBUG: gitlint.cli Platform: {platform}
+DEBUG: gitlint.cli Python version: {python_version}
+DEBUG: gitlint.cli Git version: git version 1.2.3
+DEBUG: gitlint.cli Gitlint version: {gitlint_version}
+DEBUG: gitlint.cli GITLINT_USE_SH_LIB: {GITLINT_USE_SH_LIB}
+DEBUG: gitlint.cli TERMINAL_ENCODING: {TERMINAL_ENCODING}
+DEBUG: gitlint.cli FILE_ENCODING: {FILE_ENCODING}
+DEBUG: gitlint.cli Configuration
+config-path: None
+[GENERAL]
+extra-path: None
+contrib: []
+ignore: 
+ignore-merge-commits: True
+ignore-fixup-commits: True
+ignore-fixup-amend-commits: True
+ignore-squash-commits: True
+ignore-revert-commits: True
+ignore-stdin: False
+staged: True
+fail-without-commits: False
+regex-style-search: False
+verbosity: 3
+debug: True
+target: {target}
+[RULES]
+  I1: ignore-by-title
+     ignore=all
+     regex=None
+  I2: ignore-by-body
+     ignore=all
+     regex=None
+  I3: ignore-body-lines
+     regex=None
+  I4: ignore-by-author-name
+     ignore=all
+     regex=None
+  T1: title-max-length
+     line-length=72
+  T2: title-trailing-whitespace
+  T6: title-leading-whitespace
+  T3: title-trailing-punctuation
+  T4: title-hard-tab
+  T5: title-must-not-contain-word
+     words=WIP
+  T7: title-match-regex
+     regex=None
+  T8: title-min-length
+     min-length=5
+  B1: body-max-line-length
+     line-length=80
+  B5: body-min-length
+     min-length=20
+  B6: body-is-missing
+     ignore-merge-commits=True
+  B2: body-trailing-whitespace
+  B3: body-hard-tab
+  B4: body-first-line-empty
+  B7: body-changed-file-mention
+     files=
+  B8: body-match-regex
+     regex=None
+  M1: author-valid-email
+     regex=^[^@ ]+@[^@ ]+\.[^@ ]+
+
+DEBUG: gitlint.cli Fetching additional meta-data from staged commit
+DEBUG: gitlint.cli Stdin data: 'WIP: tïtle 
+'
+DEBUG: gitlint.cli Stdin detected and not ignored. Using as input.
+DEBUG: gitlint.git ('config', '--get', 'core.commentchar')
+DEBUG: gitlint.cli Linting 1 commit(s)
+DEBUG: gitlint.lint Linting commit [SHA UNKNOWN]
+DEBUG: gitlint.git ('diff', '--staged', '--numstat', '-r')
+DEBUG: gitlint.git ('config', '--get', 'user.name')
+DEBUG: gitlint.git ('config', '--get', 'user.email')
+DEBUG: gitlint.git ('rev-parse', '--abbrev-ref', 'HEAD')
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+WIP: tïtle 
+--- Meta info ---------
+Author: föo user <föo@bar.com>
+Date:   2020-02-19 12:18:46 +0100
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: []
+Branches: ['my-branch']
+Changed Files: ['commit-1/file-1', 'commit-1/file-2']
+Changed Files Stats:
+{changed_files_stats}
+-----------------------
+DEBUG: gitlint.cli Exit Code = 3
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_1
new file mode 100644
index 0000000..a581d05
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_1
@@ -0,0 +1,4 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: tëst tïtle"
+1: T5:even-more-wörds Title contains the word 'tïtle' (case-insensitive): "WIP: tëst tïtle"
+1: T5:extra-wörds Title contains the word 'tëst' (case-insensitive): "WIP: tëst tïtle"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_2 b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_2
new file mode 100644
index 0000000..f4df46e
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli/test_named_rules_2
@@ -0,0 +1,92 @@
+DEBUG: gitlint.cli To report issues, please visit https://github.com/jorisroovers/gitlint/issues
+DEBUG: gitlint.cli Platform: {platform}
+DEBUG: gitlint.cli Python version: {python_version}
+DEBUG: gitlint.cli Git version: git version 1.2.3
+DEBUG: gitlint.cli Gitlint version: {gitlint_version}
+DEBUG: gitlint.cli GITLINT_USE_SH_LIB: {GITLINT_USE_SH_LIB}
+DEBUG: gitlint.cli TERMINAL_ENCODING: {TERMINAL_ENCODING}
+DEBUG: gitlint.cli FILE_ENCODING: {FILE_ENCODING}
+DEBUG: gitlint.cli Configuration
+config-path: {config_path}
+[GENERAL]
+extra-path: None
+contrib: []
+ignore: 
+ignore-merge-commits: True
+ignore-fixup-commits: True
+ignore-fixup-amend-commits: True
+ignore-squash-commits: True
+ignore-revert-commits: True
+ignore-stdin: False
+staged: False
+fail-without-commits: False
+regex-style-search: False
+verbosity: 3
+debug: True
+target: {target}
+[RULES]
+  I1: ignore-by-title
+     ignore=all
+     regex=None
+  I2: ignore-by-body
+     ignore=all
+     regex=None
+  I3: ignore-body-lines
+     regex=None
+  I4: ignore-by-author-name
+     ignore=all
+     regex=None
+  T1: title-max-length
+     line-length=72
+  T2: title-trailing-whitespace
+  T6: title-leading-whitespace
+  T3: title-trailing-punctuation
+  T4: title-hard-tab
+  T5: title-must-not-contain-word
+     words=WIP,bögus
+  T7: title-match-regex
+     regex=None
+  T8: title-min-length
+     min-length=5
+  B1: body-max-line-length
+     line-length=80
+  B5: body-min-length
+     min-length=20
+  B6: body-is-missing
+     ignore-merge-commits=True
+  B2: body-trailing-whitespace
+  B3: body-hard-tab
+  B4: body-first-line-empty
+  B7: body-changed-file-mention
+     files=
+  B8: body-match-regex
+     regex=None
+  M1: author-valid-email
+     regex=^[^@ ]+@[^@ ]+\.[^@ ]+
+  T5:extra-wörds: title-must-not-contain-word:extra-wörds
+     words=hür,tëst
+  T5:even-more-wörds: title-must-not-contain-word:even-more-wörds
+     words=hür,tïtle
+
+DEBUG: gitlint.cli Stdin data: 'WIP: tëst tïtle'
+DEBUG: gitlint.cli Stdin detected and not ignored. Using as input.
+DEBUG: gitlint.git ('config', '--get', 'core.commentchar')
+DEBUG: gitlint.cli Linting 1 commit(s)
+DEBUG: gitlint.lint Linting commit [SHA UNKNOWN]
+DEBUG: gitlint.lint Commit Object
+--- Commit Message ----
+WIP: tëst tïtle
+--- Meta info ---------
+Author: None <None>
+Date:   None
+is-merge-commit:  False
+is-fixup-commit:  False
+is-fixup-amend-commit: False
+is-squash-commit: False
+is-revert-commit: False
+Parents: []
+Branches: []
+Changed Files: []
+Changed Files Stats: {{}}
+-----------------------
+DEBUG: gitlint.cli Exit Code = 4
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stderr
new file mode 100644
index 0000000..cfacd42
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stderr
@@ -0,0 +1,2 @@
+1: T1 Title exceeds max length (27>5): "WIP: Test hook config tïtle"
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: Test hook config tïtle"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stdout
new file mode 100644
index 0000000..bee014b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_config_1_stdout
@@ -0,0 +1,5 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] 
+Aborted!
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stderr
new file mode 100644
index 0000000..3eb8fca
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stderr
@@ -0,0 +1,6 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "{commit_msg}"
+3: B6 Body message is missing
+1: T5 Title contains the word 'WIP' (case-insensitive): "{commit_msg}"
+3: B6 Body message is missing
+1: T5 Title contains the word 'WIP' (case-insensitive): "{commit_msg}"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stdout
new file mode 100644
index 0000000..b57a35a
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_edit_1_stdout
@@ -0,0 +1,14 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] Commit aborted.
+Your commit message: 
+-----------------------------------------------
+{commit_msg}
+-----------------------------------------------
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stderr
new file mode 100644
index 0000000..11c3cd8
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stderr
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: commït-title"
+3: B5 Body message is too short (11<20): "commït-body"
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stdout
new file mode 100644
index 0000000..0b8e90e
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_local_commit_1_stdout
@@ -0,0 +1,4 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] Editing only possible when --msg-filename is specified.
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stderr
new file mode 100644
index 0000000..6d0c9cf
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stderr
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: höok no"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stdout
new file mode 100644
index 0000000..98a83b1
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_1_stdout
@@ -0,0 +1,8 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] Commit aborted.
+Your commit message: 
+-----------------------------------------------
+WIP: höok no
+-----------------------------------------------
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stderr
new file mode 100644
index 0000000..a8d8760
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stderr
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: tïtle"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stdout
new file mode 100644
index 0000000..bee014b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_no_tty_1_stdout
@@ -0,0 +1,5 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] 
+Aborted!
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_no_violations_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_no_violations_1_stdout
new file mode 100644
index 0000000..da1ef0b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_no_violations_1_stdout
@@ -0,0 +1,2 @@
+gitlint: checking commit message...
+gitlint: OK (no violations in commit message)
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stderr
new file mode 100644
index 0000000..1404f4a
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stderr
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: Test hook stdin tïtle"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stdout
new file mode 100644
index 0000000..bee014b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_stdin_violations_1_stdout
@@ -0,0 +1,5 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] 
+Aborted!
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stderr b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stderr
new file mode 100644
index 0000000..da6f874
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stderr
@@ -0,0 +1,2 @@
+1: T5 Title contains the word 'WIP' (case-insensitive): "WIP: höok yes"
+3: B6 Body message is missing
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stdout b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stdout
new file mode 100644
index 0000000..0414712
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_hook_yes_1_stdout
@@ -0,0 +1,4 @@
+gitlint: checking commit message...
+-----------------------------------------------
+gitlint: Your commit message contains violations.
+Continue with commit anyways (this keeps the current commit message)? [y(es)/n(no)/e(dit)] 
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_1 b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_1
new file mode 100644
index 0000000..9082830
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_1
@@ -0,0 +1,2 @@
+gitlint: checking commit message...
+{git_repo} is not a git repository.
diff --git a/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_2 b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_2
new file mode 100644
index 0000000..bafbf29
--- /dev/null
+++ b/gitlint-core/gitlint/tests/expected/cli/test_cli_hooks/test_run_hook_negative_2
@@ -0,0 +1,2 @@
+gitlint: checking commit message...
+Error: The 'staged' option (--staged) can only be used when using '--msg-filename' or when piping data to gitlint via stdin.
diff --git a/gitlint-core/gitlint/tests/git/test_git.py b/gitlint-core/gitlint/tests/git/test_git.py
new file mode 100644
index 0000000..b6a146a
--- /dev/null
+++ b/gitlint-core/gitlint/tests/git/test_git.py
@@ -0,0 +1,121 @@
+import os
+from unittest.mock import call, patch
+
+from gitlint.git import (
+    GitContext,
+    GitContextError,
+    GitNotInstalledError,
+    git_commentchar,
+    git_hooks_dir,
+)
+from gitlint.shell import CommandNotFound, ErrorReturnCode
+from gitlint.tests.base import BaseTestCase
+
+
+class GitTests(BaseTestCase):
+    # Expected special_args passed to 'sh'
+    expected_sh_special_args = {"_tty_out": False, "_cwd": "fåke/path"}
+
+    @patch("gitlint.git.sh")
+    def test_get_latest_commit_command_not_found(self, sh):
+        sh.git.side_effect = CommandNotFound("git")
+        expected_msg = (
+            "'git' command not found. You need to install git to use gitlint on a local repository. "
+            + "See https://git-scm.com/book/en/v2/Getting-Started-Installing-Git on how to install git."
+        )
+        with self.assertRaisesMessage(GitNotInstalledError, expected_msg):
+            GitContext.from_local_repository("fåke/path")
+
+        # assert that commit message was read using git command
+        sh.git.assert_called_once_with("log", "-1", "--pretty=%H", **self.expected_sh_special_args)
+
+    @patch("gitlint.git.sh")
+    def test_get_latest_commit_git_error(self, sh):
+        # Current directory not a git repo
+        err = b"fatal: Not a git repository (or any of the parent directories): .git"
+        sh.git.side_effect = ErrorReturnCode("git log -1 --pretty=%H", b"", err)
+
+        with self.assertRaisesMessage(GitContextError, "fåke/path is not a git repository."):
+            GitContext.from_local_repository("fåke/path")
+
+        # assert that commit message was read using git command
+        sh.git.assert_called_once_with("log", "-1", "--pretty=%H", **self.expected_sh_special_args)
+        sh.git.reset_mock()
+
+        err = b"fatal: Random git error"
+        sh.git.side_effect = ErrorReturnCode("git log -1 --pretty=%H", b"", err)
+
+        expected_msg = f"An error occurred while executing 'git log -1 --pretty=%H': {err}"
+        with self.assertRaisesMessage(GitContextError, expected_msg):
+            GitContext.from_local_repository("fåke/path")
+
+        # assert that commit message was read using git command
+        sh.git.assert_called_once_with("log", "-1", "--pretty=%H", **self.expected_sh_special_args)
+
+    @patch("gitlint.git.sh")
+    def test_git_no_commits_error(self, sh):
+        # No commits: returned by 'git log'
+        err = b"fatal: your current branch 'main' does not have any commits yet"
+
+        sh.git.side_effect = ErrorReturnCode("git log -1 --pretty=%H", b"", err)
+
+        expected_msg = "Current branch has no commits. Gitlint requires at least one commit to function."
+        with self.assertRaisesMessage(GitContextError, expected_msg):
+            GitContext.from_local_repository("fåke/path")
+
+        # assert that commit message was read using git command
+        sh.git.assert_called_once_with("log", "-1", "--pretty=%H", **self.expected_sh_special_args)
+
+    @patch("gitlint.git.sh")
+    def test_git_no_commits_get_branch(self, sh):
+        """Check that we can still read the current branch name when there's no commits. This is useful when
+        when trying to lint the first commit using the --staged flag.
+        """
+        # Unknown reference 'HEAD' commits: returned by 'git rev-parse'
+        err = (
+            b"HEAD"
+            b"fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree."
+            b"Use '--' to separate paths from revisions, like this:"
+            b"'git <command> [<revision>...] -- [<file>...]'"
+        )
+
+        sh.git.side_effect = [
+            "#\n",  # git config --get core.commentchar
+            ErrorReturnCode("rev-parse --abbrev-ref HEAD", b"", err),
+            "test-branch",  # git branch --show-current
+        ]
+
+        context = GitContext.from_commit_msg("test")
+        self.assertEqual(context.current_branch, "test-branch")
+
+        # assert that we try using `git rev-parse` first, and if that fails (as will be the case with the first commit),
+        #  we fallback to `git branch --show-current` to determine the current branch name.
+        expected_calls = [
+            call("config", "--get", "core.commentchar", _tty_out=False, _cwd=None, _ok_code=[0, 1]),
+            call("rev-parse", "--abbrev-ref", "HEAD", _tty_out=False, _cwd=None),
+            call("branch", "--show-current", _tty_out=False, _cwd=None),
+        ]
+
+        self.assertEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git._git")
+    def test_git_commentchar(self, git):
+        git.return_value.exit_code = 1
+        self.assertEqual(git_commentchar(), "#")
+
+        git.return_value.exit_code = 0
+        git.return_value = "ä"
+        self.assertEqual(git_commentchar(), "ä")
+
+        git.return_value = ";\n"
+        self.assertEqual(git_commentchar(os.path.join("/föo", "bar")), ";")
+
+        git.assert_called_with("config", "--get", "core.commentchar", _ok_code=[0, 1], _cwd=os.path.join("/föo", "bar"))
+
+    @patch("gitlint.git._git")
+    def test_git_hooks_dir(self, git):
+        hooks_dir = os.path.join("föo", ".git", "hooks")
+        git.return_value = hooks_dir + "\n"
+        self.assertEqual(git_hooks_dir("/blä"), os.path.abspath(os.path.join("/blä", hooks_dir)))
+
+        git.assert_called_once_with("rev-parse", "--git-path", "hooks", _cwd="/blä")
diff --git a/gitlint-core/gitlint/tests/git/test_git_commit.py b/gitlint-core/gitlint/tests/git/test_git_commit.py
new file mode 100644
index 0000000..e6b0b2c
--- /dev/null
+++ b/gitlint-core/gitlint/tests/git/test_git_commit.py
@@ -0,0 +1,825 @@
+import copy
+import datetime
+from pathlib import Path
+from unittest.mock import call, patch
+
+import arrow
+import dateutil
+from gitlint.git import (
+    GitChangedFileStats,
+    GitCommit,
+    GitCommitMessage,
+    GitContext,
+    GitContextError,
+    LocalGitCommit,
+    StagedLocalGitCommit,
+)
+from gitlint.shell import ErrorReturnCode
+from gitlint.tests.base import BaseTestCase
+
+
+class GitCommitTests(BaseTestCase):
+    # Expected special_args passed to 'sh'
+    expected_sh_special_args = {"_tty_out": False, "_cwd": "fåke/path"}
+
+    @patch("gitlint.git.sh")
+    def test_get_latest_commit(self, sh):
+        sample_sha = "d8ac47e9f2923c7f22d8668e3a1ed04eb4cdbca9"
+
+        sh.git.side_effect = [
+            sample_sha,
+            "test åuthor\x00test-emåil@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\ncömmit-title\n\ncömmit-body",
+            "#",  # git config --get core.commentchar
+            "4\t15\tfile1.txt\n-\t-\tpåth/to/file2.bin\n",
+            "foöbar\n* hürdur\n",
+        ]
+
+        context = GitContext.from_local_repository("fåke/path")
+        # assert that commit info was read using git command
+        expected_calls = [
+            call("log", "-1", "--pretty=%H", **self.expected_sh_special_args),
+            call("log", sample_sha, "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call(
+                "diff-tree",
+                "--no-commit-id",
+                "--numstat",
+                "-r",
+                "--root",
+                sample_sha,
+                **self.expected_sh_special_args,
+            ),
+            call("branch", "--contains", sample_sha, **self.expected_sh_special_args),
+        ]
+
+        # Only first 'git log' call should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:1])
+
+        last_commit = context.commits[-1]
+        self.assertIsInstance(last_commit, LocalGitCommit)
+        self.assertEqual(last_commit.sha, sample_sha)
+        self.assertEqual(last_commit.message.title, "cömmit-title")
+        self.assertEqual(last_commit.message.body, ["", "cömmit-body"])
+        self.assertEqual(last_commit.author_name, "test åuthor")
+        self.assertEqual(last_commit.author_email, "test-emåil@foo.com")
+        self.assertEqual(
+            last_commit.date, datetime.datetime(2016, 12, 3, 15, 28, 15, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+        )
+        self.assertListEqual(last_commit.parents, ["åbc"])
+        self.assertFalse(last_commit.is_merge_commit)
+        self.assertFalse(last_commit.is_fixup_commit)
+        self.assertFalse(last_commit.is_fixup_amend_commit)
+        self.assertFalse(last_commit.is_squash_commit)
+        self.assertFalse(last_commit.is_revert_commit)
+
+        # First 2 'git log' calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:3])
+
+        self.assertListEqual(last_commit.changed_files, ["file1.txt", "påth/to/file2.bin"])
+        expected_file_stats = {
+            "file1.txt": GitChangedFileStats("file1.txt", 4, 15),
+            "påth/to/file2.bin": GitChangedFileStats("påth/to/file2.bin", None, None),
+        }
+        self.assertDictEqual(last_commit.changed_files_stats, expected_file_stats)
+
+        # 'git diff-tree' should have happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:4])
+
+        self.assertListEqual(last_commit.branches, ["foöbar", "hürdur"])
+        # All expected calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git.sh")
+    def test_from_local_repository_specific_refspec(self, sh):
+        sample_refspec = "åbc123..def456"
+        sample_sha = "åbc123"
+
+        sh.git.side_effect = [
+            sample_sha,  # git rev-list <sample_refspec>
+            "test åuthor\x00test-emåil@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\ncömmit-title\n\ncömmit-body",
+            "#",  # git config --get core.commentchar
+            "7\t10\tfile1.txt\n9\t12\tpåth/to/file2.txt\n",
+            "foöbar\n* hürdur\n",
+        ]
+
+        context = GitContext.from_local_repository("fåke/path", refspec=sample_refspec)
+        # assert that commit info was read using git command
+        expected_calls = [
+            call("rev-list", sample_refspec, **self.expected_sh_special_args),
+            call("log", sample_sha, "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call(
+                "diff-tree",
+                "--no-commit-id",
+                "--numstat",
+                "-r",
+                "--root",
+                sample_sha,
+                **self.expected_sh_special_args,
+            ),
+            call("branch", "--contains", sample_sha, **self.expected_sh_special_args),
+        ]
+
+        # Only first 'git log' call should've happened at this point
+        self.assertEqual(sh.git.mock_calls, expected_calls[:1])
+
+        last_commit = context.commits[-1]
+        self.assertIsInstance(last_commit, LocalGitCommit)
+        self.assertEqual(last_commit.sha, sample_sha)
+        self.assertEqual(last_commit.message.title, "cömmit-title")
+        self.assertEqual(last_commit.message.body, ["", "cömmit-body"])
+        self.assertEqual(last_commit.author_name, "test åuthor")
+        self.assertEqual(last_commit.author_email, "test-emåil@foo.com")
+        self.assertEqual(
+            last_commit.date, datetime.datetime(2016, 12, 3, 15, 28, 15, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+        )
+        self.assertListEqual(last_commit.parents, ["åbc"])
+        self.assertFalse(last_commit.is_merge_commit)
+        self.assertFalse(last_commit.is_fixup_commit)
+        self.assertFalse(last_commit.is_fixup_amend_commit)
+        self.assertFalse(last_commit.is_squash_commit)
+        self.assertFalse(last_commit.is_revert_commit)
+
+        # First 2 'git log' calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:3])
+
+        self.assertListEqual(last_commit.changed_files, ["file1.txt", "påth/to/file2.txt"])
+        expected_file_stats = {
+            "file1.txt": GitChangedFileStats("file1.txt", 7, 10),
+            "påth/to/file2.txt": GitChangedFileStats("påth/to/file2.txt", 9, 12),
+        }
+        self.assertDictEqual(last_commit.changed_files_stats, expected_file_stats)
+
+        # 'git diff-tree' should have happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:4])
+
+        self.assertListEqual(last_commit.branches, ["foöbar", "hürdur"])
+        # All expected calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git.sh")
+    def test_from_local_repository_specific_commit_hash(self, sh):
+        sample_hash = "åbc123"
+
+        sh.git.side_effect = [
+            sample_hash,  # git log -1 <sample_hash>
+            "test åuthor\x00test-emåil@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\ncömmit-title\n\ncömmit-body",
+            "#",  # git config --get core.commentchar
+            "8\t3\tfile1.txt\n1\t4\tpåth/to/file2.txt\n",
+            "foöbar\n* hürdur\n",
+        ]
+
+        context = GitContext.from_local_repository("fåke/path", commit_hashes=[sample_hash])
+        # assert that commit info was read using git command
+        expected_calls = [
+            call("log", "-1", sample_hash, "--pretty=%H", **self.expected_sh_special_args),
+            call("log", sample_hash, "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call(
+                "diff-tree",
+                "--no-commit-id",
+                "--numstat",
+                "-r",
+                "--root",
+                sample_hash,
+                **self.expected_sh_special_args,
+            ),
+            call("branch", "--contains", sample_hash, **self.expected_sh_special_args),
+        ]
+
+        # Only first 'git log' call should've happened at this point
+        self.assertEqual(sh.git.mock_calls, expected_calls[:1])
+
+        last_commit = context.commits[-1]
+        self.assertIsInstance(last_commit, LocalGitCommit)
+        self.assertEqual(last_commit.sha, sample_hash)
+        self.assertEqual(last_commit.message.title, "cömmit-title")
+        self.assertEqual(last_commit.message.body, ["", "cömmit-body"])
+        self.assertEqual(last_commit.author_name, "test åuthor")
+        self.assertEqual(last_commit.author_email, "test-emåil@foo.com")
+        self.assertEqual(
+            last_commit.date, datetime.datetime(2016, 12, 3, 15, 28, 15, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+        )
+        self.assertListEqual(last_commit.parents, ["åbc"])
+        self.assertFalse(last_commit.is_merge_commit)
+        self.assertFalse(last_commit.is_fixup_commit)
+        self.assertFalse(last_commit.is_fixup_amend_commit)
+        self.assertFalse(last_commit.is_squash_commit)
+        self.assertFalse(last_commit.is_revert_commit)
+
+        # First 2 'git log' calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:3])
+
+        self.assertListEqual(last_commit.changed_files, ["file1.txt", "påth/to/file2.txt"])
+        expected_file_stats = {
+            "file1.txt": GitChangedFileStats("file1.txt", 8, 3),
+            "påth/to/file2.txt": GitChangedFileStats("påth/to/file2.txt", 1, 4),
+        }
+        self.assertDictEqual(last_commit.changed_files_stats, expected_file_stats)
+        # 'git diff-tree' should have happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:4])
+
+        self.assertListEqual(last_commit.branches, ["foöbar", "hürdur"])
+        # All expected calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git.sh")
+    def test_from_local_repository_multiple_commit_hashes(self, sh):
+        hashes = ["åbc123", "dęf456", "ghí789"]
+        sh.git.side_effect = [
+            *hashes,
+            f"test åuthor {hashes[0]}\x00test-emåil-{hashes[0]}@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            f"cömmit-title {hashes[0]}\n\ncömmit-body {hashes[0]}",
+            "#",  # git config --get core.commentchar
+            f"test åuthor {hashes[1]}\x00test-emåil-{hashes[1]}@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            f"cömmit-title {hashes[1]}\n\ncömmit-body {hashes[1]}",
+            f"test åuthor {hashes[2]}\x00test-emåil-{hashes[2]}@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+            f"cömmit-title {hashes[2]}\n\ncömmit-body {hashes[2]}",
+            f"2\t5\tfile1-{hashes[0]}.txt\n7\t1\tpåth/to/file2.txt\n",
+            f"2\t5\tfile1-{hashes[1]}.txt\n7\t1\tpåth/to/file2.txt\n",
+            f"2\t5\tfile1-{hashes[2]}.txt\n7\t1\tpåth/to/file2.txt\n",
+            f"foöbar-{hashes[0]}\n* hürdur\n",
+            f"foöbar-{hashes[1]}\n* hürdur\n",
+            f"foöbar-{hashes[2]}\n* hürdur\n",
+        ]
+
+        expected_calls = [
+            call("log", "-1", hashes[0], "--pretty=%H", **self.expected_sh_special_args),
+            call("log", "-1", hashes[1], "--pretty=%H", **self.expected_sh_special_args),
+            call("log", "-1", hashes[2], "--pretty=%H", **self.expected_sh_special_args),
+            call("log", hashes[0], "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call("log", hashes[1], "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call("log", hashes[2], "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call(
+                "diff-tree", "--no-commit-id", "--numstat", "-r", "--root", hashes[0], **self.expected_sh_special_args
+            ),
+            call(
+                "diff-tree", "--no-commit-id", "--numstat", "-r", "--root", hashes[1], **self.expected_sh_special_args
+            ),
+            call(
+                "diff-tree", "--no-commit-id", "--numstat", "-r", "--root", hashes[2], **self.expected_sh_special_args
+            ),
+            call("branch", "--contains", hashes[0], **self.expected_sh_special_args),
+            call("branch", "--contains", hashes[1], **self.expected_sh_special_args),
+            call("branch", "--contains", hashes[2], **self.expected_sh_special_args),
+        ]
+
+        context = GitContext.from_local_repository("fåke/path", commit_hashes=hashes)
+
+        # Only first set of 'git log' calls should've happened at this point
+        self.assertEqual(sh.git.mock_calls, expected_calls[:3])
+
+        for i, commit in enumerate(context.commits):
+            expected_hash = hashes[i]
+            self.assertIsInstance(commit, LocalGitCommit)
+            self.assertEqual(commit.sha, expected_hash)
+            self.assertEqual(commit.message.title, f"cömmit-title {expected_hash}")
+            self.assertEqual(commit.message.body, ["", f"cömmit-body {expected_hash}"])
+            self.assertEqual(commit.author_name, f"test åuthor {expected_hash}")
+            self.assertEqual(commit.author_email, f"test-emåil-{expected_hash}@foo.com")
+            self.assertEqual(
+                commit.date, datetime.datetime(2016, 12, 3, 15, 28, 15, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+            )
+            self.assertListEqual(commit.parents, ["åbc"])
+            self.assertFalse(commit.is_merge_commit)
+            self.assertFalse(commit.is_fixup_commit)
+            self.assertFalse(commit.is_fixup_amend_commit)
+            self.assertFalse(commit.is_squash_commit)
+            self.assertFalse(commit.is_revert_commit)
+
+        # All 'git log' calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:7])
+
+        for i, commit in enumerate(context.commits):
+            expected_hash = hashes[i]
+            self.assertListEqual(commit.changed_files, [f"file1-{expected_hash}.txt", "påth/to/file2.txt"])
+            expected_file_stats = {
+                f"file1-{expected_hash}.txt": GitChangedFileStats(f"file1-{expected_hash}.txt", 2, 5),
+                "påth/to/file2.txt": GitChangedFileStats("påth/to/file2.txt", 7, 1),
+            }
+            self.assertDictEqual(commit.changed_files_stats, expected_file_stats)
+
+        # 'git diff-tree' should have happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:10])
+
+        for i, commit in enumerate(context.commits):
+            expected_hash = hashes[i]
+            self.assertListEqual(commit.branches, [f"foöbar-{expected_hash}", "hürdur"])
+
+        # All expected calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git.sh")
+    def test_get_latest_commit_merge_commit(self, sh):
+        sample_sha = "d8ac47e9f2923c7f22d8668e3a1ed04eb4cdbca9"
+
+        sh.git.side_effect = [
+            sample_sha,
+            'test åuthor\x00test-emåil@foo.com\x002016-12-03 15:28:15 +0100\x00åbc def\nMerge "foo bår commit"',
+            "#",  # git config --get core.commentchar
+            "6\t2\tfile1.txt\n1\t4\tpåth/to/file2.txt\n",
+            "foöbar\n* hürdur\n",
+        ]
+
+        context = GitContext.from_local_repository("fåke/path")
+        # assert that commit info was read using git command
+        expected_calls = [
+            call("log", "-1", "--pretty=%H", **self.expected_sh_special_args),
+            call("log", sample_sha, "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call(
+                "diff-tree",
+                "--no-commit-id",
+                "--numstat",
+                "-r",
+                "--root",
+                sample_sha,
+                **self.expected_sh_special_args,
+            ),
+            call("branch", "--contains", sample_sha, **self.expected_sh_special_args),
+        ]
+
+        # Only first 'git log' call should've happened at this point
+        self.assertEqual(sh.git.mock_calls, expected_calls[:1])
+
+        last_commit = context.commits[-1]
+        self.assertIsInstance(last_commit, LocalGitCommit)
+        self.assertEqual(last_commit.sha, sample_sha)
+        self.assertEqual(last_commit.message.title, 'Merge "foo bår commit"')
+        self.assertEqual(last_commit.message.body, [])
+        self.assertEqual(last_commit.author_name, "test åuthor")
+        self.assertEqual(last_commit.author_email, "test-emåil@foo.com")
+        self.assertEqual(
+            last_commit.date, datetime.datetime(2016, 12, 3, 15, 28, 15, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+        )
+        self.assertListEqual(last_commit.parents, ["åbc", "def"])
+        self.assertTrue(last_commit.is_merge_commit)
+        self.assertFalse(last_commit.is_fixup_commit)
+        self.assertFalse(last_commit.is_fixup_amend_commit)
+        self.assertFalse(last_commit.is_squash_commit)
+        self.assertFalse(last_commit.is_revert_commit)
+
+        # First 2 'git log' calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:3])
+
+        self.assertListEqual(last_commit.changed_files, ["file1.txt", "påth/to/file2.txt"])
+        expected_file_stats = {
+            "file1.txt": GitChangedFileStats("file1.txt", 6, 2),
+            "påth/to/file2.txt": GitChangedFileStats("påth/to/file2.txt", 1, 4),
+        }
+        self.assertDictEqual(last_commit.changed_files_stats, expected_file_stats)
+        # 'git diff-tree' should have happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[:4])
+
+        self.assertListEqual(last_commit.branches, ["foöbar", "hürdur"])
+        # All expected calls should've happened at this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git.sh")
+    def test_get_latest_commit_fixup_squash_commit(self, sh):
+        commit_prefixes = {"fixup": "is_fixup_commit", "squash": "is_squash_commit", "amend": "is_fixup_amend_commit"}
+        for commit_type in commit_prefixes:
+            sample_sha = "d8ac47e9f2923c7f22d8668e3a1ed04eb4cdbca9"
+
+            sh.git.side_effect = [
+                sample_sha,
+                "test åuthor\x00test-emåil@foo.com\x002016-12-03 15:28:15 +0100\x00åbc\n"
+                f'{commit_type}! "foo bår commit"',
+                "#",  # git config --get core.commentchar
+                "8\t2\tfile1.txt\n7\t3\tpåth/to/file2.txt\n",
+                "foöbar\n* hürdur\n",
+            ]
+
+            context = GitContext.from_local_repository("fåke/path")
+            # assert that commit info was read using git command
+            expected_calls = [
+                call("log", "-1", "--pretty=%H", **self.expected_sh_special_args),
+                call("log", sample_sha, "-1", "--pretty=%aN%x00%aE%x00%ai%x00%P%n%B", **self.expected_sh_special_args),
+                call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+                call(
+                    "diff-tree",
+                    "--no-commit-id",
+                    "--numstat",
+                    "-r",
+                    "--root",
+                    sample_sha,
+                    **self.expected_sh_special_args,
+                ),
+                call("branch", "--contains", sample_sha, **self.expected_sh_special_args),
+            ]
+
+            # Only first 'git log' call should've happened at this point
+            self.assertEqual(sh.git.mock_calls, expected_calls[:-4])
+
+            last_commit = context.commits[-1]
+            self.assertIsInstance(last_commit, LocalGitCommit)
+            self.assertEqual(last_commit.sha, sample_sha)
+            self.assertEqual(last_commit.message.title, f'{commit_type}! "foo bår commit"')
+            self.assertEqual(last_commit.message.body, [])
+            self.assertEqual(last_commit.author_name, "test åuthor")
+            self.assertEqual(last_commit.author_email, "test-emåil@foo.com")
+            self.assertEqual(
+                last_commit.date, datetime.datetime(2016, 12, 3, 15, 28, 15, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+            )
+            self.assertListEqual(last_commit.parents, ["åbc"])
+
+            # First 2 'git log' calls should've happened at this point
+            self.assertEqual(sh.git.mock_calls, expected_calls[:3])
+
+            # Asserting that squash and fixup are correct
+            for type, attr in commit_prefixes.items():
+                self.assertEqual(getattr(last_commit, attr), commit_type == type)
+
+            self.assertFalse(last_commit.is_merge_commit)
+            self.assertFalse(last_commit.is_revert_commit)
+            self.assertListEqual(last_commit.changed_files, ["file1.txt", "påth/to/file2.txt"])
+            expected_file_stats = {
+                "file1.txt": GitChangedFileStats("file1.txt", 8, 2),
+                "påth/to/file2.txt": GitChangedFileStats("påth/to/file2.txt", 7, 3),
+            }
+            self.assertDictEqual(last_commit.changed_files_stats, expected_file_stats)
+
+            # 'git diff-tree' should have happened at this point
+            self.assertListEqual(sh.git.mock_calls, expected_calls[:4])
+
+            self.assertListEqual(last_commit.branches, ["foöbar", "hürdur"])
+            # All expected calls should've happened at this point
+            self.assertListEqual(sh.git.mock_calls, expected_calls)
+
+            sh.git.reset_mock()
+
+    @patch("gitlint.git.git_commentchar")
+    def test_from_commit_msg_full(self, commentchar):
+        commentchar.return_value = "#"
+        gitcontext = GitContext.from_commit_msg(self.get_sample("commit_message/sample1"))
+
+        expected_title = "Commit title contåining 'WIP', as well as trailing punctuation."
+        expected_body = [
+            "This line should be empty",
+            "This is the first line of the commit message body and it is meant to test a "
+            + "line that exceeds the maximum line length of 80 characters.",
+            "This line has a tråiling space. ",
+            "This line has a trailing tab.\t",
+        ]
+        expected_full = expected_title + "\n" + "\n".join(expected_body)
+        expected_original = (
+            expected_full + "\n# This is a cömmented  line\n"
+            "# ------------------------ >8 ------------------------\n"
+            "# Anything after this line should be cleaned up\n"
+            "# this line appears on `git commit -v` command\n"
+            "diff --git a/gitlint/tests/samples/commit_message/sample1 "
+            "b/gitlint/tests/samples/commit_message/sample1\n"
+            "index 82dbe7f..ae71a14 100644\n"
+            "--- a/gitlint/tests/samples/commit_message/sample1\n"
+            "+++ b/gitlint/tests/samples/commit_message/sample1\n"
+            "@@ -1 +1 @@\n"
+        )
+
+        commit = gitcontext.commits[-1]
+        self.assertIsInstance(commit, GitCommit)
+        self.assertFalse(isinstance(commit, LocalGitCommit))
+        self.assertEqual(commit.message.title, expected_title)
+        self.assertEqual(commit.message.body, expected_body)
+        self.assertEqual(commit.message.full, expected_full)
+        self.assertEqual(commit.message.original, expected_original)
+        self.assertEqual(commit.author_name, None)
+        self.assertEqual(commit.author_email, None)
+        self.assertEqual(commit.date, None)
+        self.assertListEqual(commit.parents, [])
+        self.assertListEqual(commit.branches, [])
+        self.assertFalse(commit.is_merge_commit)
+        self.assertFalse(commit.is_fixup_commit)
+        self.assertFalse(commit.is_fixup_amend_commit)
+        self.assertFalse(commit.is_squash_commit)
+        self.assertFalse(commit.is_revert_commit)
+        self.assertEqual(len(gitcontext.commits), 1)
+
+    def test_from_commit_msg_just_title(self):
+        gitcontext = GitContext.from_commit_msg(self.get_sample("commit_message/sample2"))
+        commit = gitcontext.commits[-1]
+
+        self.assertIsInstance(commit, GitCommit)
+        self.assertFalse(isinstance(commit, LocalGitCommit))
+        self.assertEqual(commit.message.title, "Just a title contåining WIP")
+        self.assertEqual(commit.message.body, [])
+        self.assertEqual(commit.message.full, "Just a title contåining WIP")
+        self.assertEqual(commit.message.original, "Just a title contåining WIP")
+        self.assertEqual(commit.author_name, None)
+        self.assertEqual(commit.author_email, None)
+        self.assertListEqual(commit.parents, [])
+        self.assertListEqual(commit.branches, [])
+        self.assertFalse(commit.is_merge_commit)
+        self.assertFalse(commit.is_fixup_commit)
+        self.assertFalse(commit.is_fixup_amend_commit)
+        self.assertFalse(commit.is_squash_commit)
+        self.assertFalse(commit.is_revert_commit)
+        self.assertEqual(len(gitcontext.commits), 1)
+
+    def test_from_commit_msg_empty(self):
+        gitcontext = GitContext.from_commit_msg("")
+        commit = gitcontext.commits[-1]
+
+        self.assertIsInstance(commit, GitCommit)
+        self.assertFalse(isinstance(commit, LocalGitCommit))
+        self.assertEqual(commit.message.title, "")
+        self.assertEqual(commit.message.body, [])
+        self.assertEqual(commit.message.full, "")
+        self.assertEqual(commit.message.original, "")
+        self.assertEqual(commit.author_name, None)
+        self.assertEqual(commit.author_email, None)
+        self.assertEqual(commit.date, None)
+        self.assertListEqual(commit.parents, [])
+        self.assertListEqual(commit.branches, [])
+        self.assertFalse(commit.is_merge_commit)
+        self.assertFalse(commit.is_fixup_commit)
+        self.assertFalse(commit.is_fixup_amend_commit)
+        self.assertFalse(commit.is_squash_commit)
+        self.assertFalse(commit.is_revert_commit)
+        self.assertEqual(len(gitcontext.commits), 1)
+
+    @patch("gitlint.git.git_commentchar")
+    def test_from_commit_msg_comment(self, commentchar):
+        commentchar.return_value = "#"
+        gitcontext = GitContext.from_commit_msg("Tïtle\n\nBödy 1\n#Cömment\nBody 2")
+        commit = gitcontext.commits[-1]
+
+        self.assertIsInstance(commit, GitCommit)
+        self.assertFalse(isinstance(commit, LocalGitCommit))
+        self.assertEqual(commit.message.title, "Tïtle")
+        self.assertEqual(commit.message.body, ["", "Bödy 1", "Body 2"])
+        self.assertEqual(commit.message.full, "Tïtle\n\nBödy 1\nBody 2")
+        self.assertEqual(commit.message.original, "Tïtle\n\nBödy 1\n#Cömment\nBody 2")
+        self.assertEqual(commit.author_name, None)
+        self.assertEqual(commit.author_email, None)
+        self.assertEqual(commit.date, None)
+        self.assertListEqual(commit.parents, [])
+        self.assertListEqual(commit.branches, [])
+        self.assertFalse(commit.is_merge_commit)
+        self.assertFalse(commit.is_fixup_commit)
+        self.assertFalse(commit.is_squash_commit)
+        self.assertFalse(commit.is_fixup_amend_commit)
+        self.assertFalse(commit.is_revert_commit)
+        self.assertEqual(len(gitcontext.commits), 1)
+
+    def test_from_commit_msg_merge_commit(self):
+        commit_msg = "Merge f919b8f34898d9b48048bcd703bc47139f4ff621 into 8b0409a26da6ba8a47c1fd2e746872a8dab15401"
+        gitcontext = GitContext.from_commit_msg(commit_msg)
+        commit = gitcontext.commits[-1]
+
+        self.assertIsInstance(commit, GitCommit)
+        self.assertFalse(isinstance(commit, LocalGitCommit))
+        self.assertEqual(commit.message.title, commit_msg)
+        self.assertEqual(commit.message.body, [])
+        self.assertEqual(commit.message.full, commit_msg)
+        self.assertEqual(commit.message.original, commit_msg)
+        self.assertEqual(commit.author_name, None)
+        self.assertEqual(commit.author_email, None)
+        self.assertEqual(commit.date, None)
+        self.assertListEqual(commit.parents, [])
+        self.assertListEqual(commit.branches, [])
+        self.assertTrue(commit.is_merge_commit)
+        self.assertFalse(commit.is_fixup_commit)
+        self.assertFalse(commit.is_fixup_amend_commit)
+        self.assertFalse(commit.is_squash_commit)
+        self.assertFalse(commit.is_revert_commit)
+        self.assertEqual(len(gitcontext.commits), 1)
+
+    def test_from_commit_msg_revert_commit(self):
+        commit_msg = 'Revert "Prev commit message"\n\nThis reverts commit a8ad67e04164a537198dea94a4fde81c5592ae9c.'
+        gitcontext = GitContext.from_commit_msg(commit_msg)
+        commit = gitcontext.commits[-1]
+
+        self.assertIsInstance(commit, GitCommit)
+        self.assertFalse(isinstance(commit, LocalGitCommit))
+        self.assertEqual(commit.message.title, 'Revert "Prev commit message"')
+        self.assertEqual(commit.message.body, ["", "This reverts commit a8ad67e04164a537198dea94a4fde81c5592ae9c."])
+        self.assertEqual(commit.message.full, commit_msg)
+        self.assertEqual(commit.message.original, commit_msg)
+        self.assertEqual(commit.author_name, None)
+        self.assertEqual(commit.author_email, None)
+        self.assertEqual(commit.date, None)
+        self.assertListEqual(commit.parents, [])
+        self.assertListEqual(commit.branches, [])
+        self.assertFalse(commit.is_merge_commit)
+        self.assertFalse(commit.is_fixup_commit)
+        self.assertFalse(commit.is_fixup_amend_commit)
+        self.assertFalse(commit.is_squash_commit)
+        self.assertTrue(commit.is_revert_commit)
+        self.assertEqual(len(gitcontext.commits), 1)
+
+    def test_from_commit_msg_fixup_squash_amend_commit(self):
+        # mapping between cleanup commit prefixes and the commit object attribute
+        commit_prefixes = {"fixup": "is_fixup_commit", "squash": "is_squash_commit", "amend": "is_fixup_amend_commit"}
+
+        for commit_type in commit_prefixes:
+            commit_msg = f"{commit_type}! Test message"
+            gitcontext = GitContext.from_commit_msg(commit_msg)
+            commit = gitcontext.commits[-1]
+
+            self.assertIsInstance(commit, GitCommit)
+            self.assertFalse(isinstance(commit, LocalGitCommit))
+            self.assertEqual(commit.message.title, commit_msg)
+            self.assertEqual(commit.message.body, [])
+            self.assertEqual(commit.message.full, commit_msg)
+            self.assertEqual(commit.message.original, commit_msg)
+            self.assertEqual(commit.author_name, None)
+            self.assertEqual(commit.author_email, None)
+            self.assertEqual(commit.date, None)
+            self.assertListEqual(commit.parents, [])
+            self.assertListEqual(commit.branches, [])
+            self.assertEqual(len(gitcontext.commits), 1)
+            self.assertFalse(commit.is_merge_commit)
+            self.assertFalse(commit.is_revert_commit)
+            # Asserting that squash and fixup are correct
+            for type, commit_attr_name in commit_prefixes.items():
+                self.assertEqual(getattr(commit, commit_attr_name), commit_type == type)
+
+    @patch("gitlint.git.sh")
+    @patch("arrow.now")
+    def test_staged_commit(self, now, sh):
+        """Test for StagedLocalGitCommit()"""
+
+        sh.git.side_effect = [
+            "#",  # git config --get core.commentchar
+            "test åuthor\n",  # git config --get user.name
+            "test-emåil@foo.com\n",  # git config --get user.email
+            "my-brånch\n",  # git rev-parse --abbrev-ref HEAD
+            "4\t2\tfile1.txt\n13\t9\tpåth/to/file2.txt\n",
+        ]
+        now.side_effect = [arrow.get("2020-02-19T12:18:46.675182+01:00")]
+
+        # We use a fixup commit, just to test a non-default path
+        context = GitContext.from_staged_commit("fixup! Foōbar 123\n\ncömmit-body\n", "fåke/path")
+
+        # git calls we're expecting
+        expected_calls = [
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call("config", "--get", "user.name", **self.expected_sh_special_args),
+            call("config", "--get", "user.email", **self.expected_sh_special_args),
+            call("rev-parse", "--abbrev-ref", "HEAD", **self.expected_sh_special_args),
+            call("diff", "--staged", "--numstat", "-r", **self.expected_sh_special_args),
+        ]
+
+        last_commit = context.commits[-1]
+        self.assertIsInstance(last_commit, StagedLocalGitCommit)
+        self.assertIsNone(last_commit.sha, None)
+        self.assertEqual(last_commit.message.title, "fixup! Foōbar 123")
+        self.assertEqual(last_commit.message.body, ["", "cömmit-body"])
+        # Only `git config --get core.commentchar` should've happened up until this point
+        self.assertListEqual(sh.git.mock_calls, expected_calls[0:1])
+
+        self.assertEqual(last_commit.author_name, "test åuthor")
+        self.assertListEqual(sh.git.mock_calls, expected_calls[0:2])
+
+        self.assertEqual(last_commit.author_email, "test-emåil@foo.com")
+        self.assertListEqual(sh.git.mock_calls, expected_calls[0:3])
+
+        self.assertEqual(
+            last_commit.date, datetime.datetime(2020, 2, 19, 12, 18, 46, tzinfo=dateutil.tz.tzoffset("+0100", 3600))
+        )
+        now.assert_called_once()
+
+        self.assertListEqual(last_commit.parents, [])
+        self.assertFalse(last_commit.is_merge_commit)
+        self.assertTrue(last_commit.is_fixup_commit)
+        self.assertFalse(last_commit.is_fixup_amend_commit)
+        self.assertFalse(last_commit.is_squash_commit)
+        self.assertFalse(last_commit.is_revert_commit)
+
+        self.assertListEqual(last_commit.branches, ["my-brånch"])
+        self.assertListEqual(sh.git.mock_calls, expected_calls[0:4])
+
+        self.assertListEqual(last_commit.changed_files, ["file1.txt", "påth/to/file2.txt"])
+        expected_file_stats = {
+            "file1.txt": GitChangedFileStats("file1.txt", 4, 2),
+            "påth/to/file2.txt": GitChangedFileStats("påth/to/file2.txt", 13, 9),
+        }
+        self.assertDictEqual(last_commit.changed_files_stats, expected_file_stats)
+
+        self.assertListEqual(sh.git.mock_calls, expected_calls[0:5])
+
+    @patch("gitlint.git.sh")
+    def test_staged_commit_with_missing_username(self, sh):
+        sh.git.side_effect = [
+            "#",  # git config --get core.commentchar
+            ErrorReturnCode("git config --get user.name", b"", b""),
+        ]
+
+        expected_msg = "Missing git configuration: please set user.name"
+        with self.assertRaisesMessage(GitContextError, expected_msg):
+            ctx = GitContext.from_staged_commit("Foōbar 123\n\ncömmit-body\n", "fåke/path")
+            ctx.commits[0].author_name  # accessing this attribute should raise an exception
+
+    @patch("gitlint.git.sh")
+    def test_staged_commit_with_missing_email(self, sh):
+        sh.git.side_effect = [
+            "#",  # git config --get core.commentchar
+            ErrorReturnCode("git config --get user.email", b"", b""),
+        ]
+
+        expected_msg = "Missing git configuration: please set user.email"
+        with self.assertRaisesMessage(GitContextError, expected_msg):
+            ctx = GitContext.from_staged_commit("Foōbar 123\n\ncömmit-body\n", "fåke/path")
+            ctx.commits[0].author_email  # accessing this attribute should raise an exception
+
+    def test_gitcommitmessage_equality(self):
+        commit_message1 = GitCommitMessage(GitContext(), "tëst\n\nfoo", "tëst\n\nfoo", "tēst", ["", "föo"])
+        attrs = ["original", "full", "title", "body"]
+        self.object_equality_test(commit_message1, attrs, {"context": commit_message1.context})
+
+    def test_gitchangedfilestats_equality(self):
+        changed_file_stats = GitChangedFileStats(Path("foö/bar"), 5, 13)
+        attrs = ["filepath", "additions", "deletions"]
+        self.object_equality_test(changed_file_stats, attrs)
+
+    @patch("gitlint.git._git")
+    def test_gitcommit_equality(self, git):
+        # git will be called to setup the context (commentchar and current_branch), just return the same value
+        # This only matters to test gitcontext equality, not gitcommit equality
+        git.return_value = "foöbar"
+
+        # Test simple equality case
+        now = datetime.datetime.now(datetime.timezone.utc)
+        context1 = GitContext()
+        commit_message1 = GitCommitMessage(context1, "tëst\n\nfoo", "tëst\n\nfoo", "tēst", ["", "föo"])
+        commit1 = GitCommit(
+            context1,
+            commit_message1,
+            "shä",
+            now,
+            "Jöhn Smith",
+            "jöhn.smith@test.com",
+            None,
+            {"föo/bar": GitChangedFileStats("föo/bar", 5, 13)},
+            ["brånch1", "brånch2"],
+        )
+        context1.commits = [commit1]
+
+        context2 = GitContext()
+        commit_message2 = GitCommitMessage(context2, "tëst\n\nfoo", "tëst\n\nfoo", "tēst", ["", "föo"])
+        commit2 = GitCommit(
+            context2,
+            commit_message1,
+            "shä",
+            now,
+            "Jöhn Smith",
+            "jöhn.smith@test.com",
+            None,
+            {"föo/bar": GitChangedFileStats("föo/bar", 5, 13)},
+            ["brånch1", "brånch2"],
+        )
+        context2.commits = [commit2]
+
+        self.assertEqual(context1, context2)
+        self.assertEqual(commit_message1, commit_message2)
+        self.assertEqual(commit1, commit2)
+
+        # Check that objects are unequal when changing a single attribute
+        kwargs = {
+            "message": commit1.message,
+            "sha": commit1.sha,
+            "date": commit1.date,
+            "author_name": commit1.author_name,
+            "author_email": commit1.author_email,
+            "parents": commit1.parents,
+            "branches": commit1.branches,
+        }
+
+        self.object_equality_test(
+            commit1,
+            kwargs.keys(),
+            {"context": commit1.context, "changed_files_stats": {"föo/bar": GitChangedFileStats("föo/bar", 5, 13)}},
+        )
+
+        # Check that the is_* attributes that are affected by the commit message affect equality
+        special_messages = {
+            "is_merge_commit": "Merge: foöbar",
+            "is_fixup_commit": "fixup! foöbar",
+            "is_squash_commit": "squash! foöbar",
+            "is_revert_commit": "Revert: foöbar",
+        }
+        for key in special_messages:
+            kwargs_copy = copy.deepcopy(kwargs)
+            clone1 = GitCommit(context=commit1.context, **kwargs_copy)
+            clone1.message = GitCommitMessage.from_full_message(context1, special_messages[key])
+            self.assertTrue(getattr(clone1, key))
+
+            clone2 = GitCommit(context=commit1.context, **kwargs_copy)
+            clone2.message = GitCommitMessage.from_full_message(context1, "foöbar")
+            self.assertNotEqual(clone1, clone2)
+
+        # Check changed_files and changed_files_stats
+        commit2.changed_files_stats = {"föo/bar2": GitChangedFileStats("föo/bar2", 5, 13)}
+        self.assertNotEqual(commit1, commit2)
+
+    @patch("gitlint.git.git_commentchar")
+    def test_commit_msg_custom_commentchar(self, patched):
+        patched.return_value = "ä"
+        context = GitContext()
+        message = GitCommitMessage.from_full_message(context, "Tïtle\n\nBödy 1\näCömment\nBody 2")
+
+        self.assertEqual(message.title, "Tïtle")
+        self.assertEqual(message.body, ["", "Bödy 1", "Body 2"])
+        self.assertEqual(message.full, "Tïtle\n\nBödy 1\nBody 2")
+        self.assertEqual(message.original, "Tïtle\n\nBödy 1\näCömment\nBody 2")
diff --git a/gitlint-core/gitlint/tests/git/test_git_context.py b/gitlint-core/gitlint/tests/git/test_git_context.py
new file mode 100644
index 0000000..751136c
--- /dev/null
+++ b/gitlint-core/gitlint/tests/git/test_git_context.py
@@ -0,0 +1,73 @@
+from unittest.mock import call, patch
+
+from gitlint.git import GitContext
+from gitlint.tests.base import BaseTestCase
+
+
+class GitContextTests(BaseTestCase):
+    # Expected special_args passed to 'sh'
+    expected_sh_special_args = {"_tty_out": False, "_cwd": "fåke/path"}
+
+    @patch("gitlint.git.sh")
+    def test_gitcontext(self, sh):
+        sh.git.side_effect = ["#", "\nfoöbar\n"]  # git config --get core.commentchar
+
+        expected_calls = [
+            call("config", "--get", "core.commentchar", _ok_code=[0, 1], **self.expected_sh_special_args),
+            call("rev-parse", "--abbrev-ref", "HEAD", **self.expected_sh_special_args),
+        ]
+
+        context = GitContext("fåke/path")
+        self.assertEqual(sh.git.mock_calls, [])
+
+        # gitcontext.comment_branch
+        self.assertEqual(context.commentchar, "#")
+        self.assertEqual(sh.git.mock_calls, expected_calls[0:1])
+
+        # gitcontext.current_branch
+        self.assertEqual(context.current_branch, "foöbar")
+        self.assertEqual(sh.git.mock_calls, expected_calls)
+
+    @patch("gitlint.git.sh")
+    def test_gitcontext_equality(self, sh):
+        sh.git.side_effect = [
+            "û\n",  # context1: git config --get core.commentchar
+            "û\n",  # context2: git config --get core.commentchar
+            "my-brånch\n",  # context1: git rev-parse --abbrev-ref HEAD
+            "my-brånch\n",  # context2: git rev-parse --abbrev-ref HEAD
+        ]
+
+        context1 = GitContext("fåke/path")
+        context1.commits = ["fōo", "bår"]  # we don't need real commits to check for equality
+
+        context2 = GitContext("fåke/path")
+        context2.commits = ["fōo", "bår"]
+        self.assertEqual(context1, context2)
+
+        # INEQUALITY
+        # Different commits
+        context2.commits = ["hür", "dür"]
+        self.assertNotEqual(context1, context2)
+
+        # Different repository_path
+        context2.commits = context1.commits
+        context2.repository_path = "ōther/path"
+        self.assertNotEqual(context1, context2)
+
+        # Different comment_char
+        context3 = GitContext("fåke/path")
+        context3.commits = ["fōo", "bår"]
+        sh.git.side_effect = [
+            "ç\n",  # context3: git config --get core.commentchar
+            "my-brånch\n",  # context3: git rev-parse --abbrev-ref HEAD
+        ]
+        self.assertNotEqual(context1, context3)
+
+        # Different current_branch
+        context4 = GitContext("fåke/path")
+        context4.commits = ["fōo", "bår"]
+        sh.git.side_effect = [
+            "û\n",  # context4: git config --get core.commentchar
+            "different-brånch\n",  # context4: git rev-parse --abbrev-ref HEAD
+        ]
+        self.assertNotEqual(context1, context4)
diff --git a/gitlint-core/gitlint/tests/rules/__init__.py b/gitlint-core/gitlint/tests/rules/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/gitlint-core/gitlint/tests/rules/test_body_rules.py b/gitlint-core/gitlint/tests/rules/test_body_rules.py
new file mode 100644
index 0000000..c142e6e
--- /dev/null
+++ b/gitlint-core/gitlint/tests/rules/test_body_rules.py
@@ -0,0 +1,235 @@
+from gitlint import rules
+from gitlint.tests.base import BaseTestCase
+
+
+class BodyRuleTests(BaseTestCase):
+    def test_max_line_length(self):
+        rule = rules.BodyMaxLineLength()
+
+        # assert no error
+        violation = rule.validate("å" * 80, None)
+        self.assertIsNone(violation)
+
+        # assert error on line length > 80
+        expected_violation = rules.RuleViolation("B1", "Line exceeds max length (81>80)", "å" * 81)
+        violations = rule.validate("å" * 81, None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # set line length to 120, and check no violation on length 73
+        rule = rules.BodyMaxLineLength({"line-length": 120})
+        violations = rule.validate("å" * 73, None)
+        self.assertIsNone(violations)
+
+        # assert raise on 121
+        expected_violation = rules.RuleViolation("B1", "Line exceeds max length (121>120)", "å" * 121)
+        violations = rule.validate("å" * 121, None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_trailing_whitespace(self):
+        rule = rules.BodyTrailingWhitespace()
+
+        # assert no error
+        violations = rule.validate("å", None)
+        self.assertIsNone(violations)
+
+        # trailing space
+        expected_violation = rules.RuleViolation("B2", "Line has trailing whitespace", "å ")
+        violations = rule.validate("å ", None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # trailing tab
+        expected_violation = rules.RuleViolation("B2", "Line has trailing whitespace", "å\t")
+        violations = rule.validate("å\t", None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_hard_tabs(self):
+        rule = rules.BodyHardTab()
+
+        # assert no error
+        violations = rule.validate("This is ã test", None)
+        self.assertIsNone(violations)
+
+        # contains hard tab
+        expected_violation = rules.RuleViolation("B3", "Line contains hard tab characters (\\t)", "This is å\ttest")
+        violations = rule.validate("This is å\ttest", None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_body_first_line_empty(self):
+        rule = rules.BodyFirstLineEmpty()
+
+        # assert no error
+        commit = self.gitcommit("Tïtle\n\nThis is the secōnd body line")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # second line not empty
+        expected_violation = rules.RuleViolation("B4", "Second line is not empty", "nöt empty", 2)
+
+        commit = self.gitcommit("Tïtle\nnöt empty\nThis is the secönd body line")
+        violations = rule.validate(commit)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_body_min_length(self):
+        rule = rules.BodyMinLength()
+
+        # assert no error - body is long enough
+        commit = self.gitcommit("Title\n\nThis is the second body line\n")
+
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert no error - no body
+        commit = self.gitcommit("Tïtle\n")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # body is too short
+        expected_violation = rules.RuleViolation("B5", "Body message is too short (8<20)", "töoshort", 3)
+
+        commit = self.gitcommit("Tïtle\n\ntöoshort\n")
+        violations = rule.validate(commit)
+        self.assertListEqual(violations, [expected_violation])
+
+        # assert error - short across multiple lines
+        expected_violation = rules.RuleViolation("B5", "Body message is too short (11<20)", "secöndthïrd", 3)
+        commit = self.gitcommit("Tïtle\n\nsecönd\nthïrd\n")
+        violations = rule.validate(commit)
+        self.assertListEqual(violations, [expected_violation])
+
+        # set line length to 120, and check violation on length 21
+        expected_violation = rules.RuleViolation("B5", "Body message is too short (21<120)", "å" * 21, 3)
+
+        rule = rules.BodyMinLength({"min-length": 120})
+        commit = self.gitcommit("Title\n\n{}\n".format("å" * 21))
+        violations = rule.validate(commit)
+        self.assertListEqual(violations, [expected_violation])
+
+        # Make sure we don't get the error if the body-length is exactly the min-length
+        rule = rules.BodyMinLength({"min-length": 8})
+        commit = self.gitcommit("Tïtle\n\n{}\n".format("å" * 8))
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+    def test_body_missing(self):
+        rule = rules.BodyMissing()
+
+        # assert no error - body is present
+        commit = self.gitcommit("Tïtle\n\nThis ïs the first body line\n")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # body is too short
+        expected_violation = rules.RuleViolation("B6", "Body message is missing", None, 3)
+
+        commit = self.gitcommit("Tïtle\n")
+        violations = rule.validate(commit)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_body_missing_multiple_empty_new_lines(self):
+        rule = rules.BodyMissing()
+
+        # body is too short
+        expected_violation = rules.RuleViolation("B6", "Body message is missing", None, 3)
+
+        commit = self.gitcommit("Tïtle\n\n\n\n")
+        violations = rule.validate(commit)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_body_missing_merge_commit(self):
+        rule = rules.BodyMissing()
+
+        # assert no error - merge commit
+        commit = self.gitcommit("Merge: Tïtle\n")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert error for merge commits if ignore-merge-commits is disabled
+        rule = rules.BodyMissing({"ignore-merge-commits": False})
+        violations = rule.validate(commit)
+        expected_violation = rules.RuleViolation("B6", "Body message is missing", None, 3)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_body_changed_file_mention(self):
+        rule = rules.BodyChangedFileMention()
+
+        # assert no error when no files have changed and no files need to be mentioned
+        commit = self.gitcommit("This is a test\n\nHere is a mention of föo/test.py")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert no error when no files have changed but certain files need to be mentioned on change
+        rule = rules.BodyChangedFileMention({"files": "bar.txt,föo/test.py"})
+        commit = self.gitcommit("This is a test\n\nHere is a mention of föo/test.py")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert no error if a file has changed and is mentioned
+        commit = self.gitcommit("This is a test\n\nHere is a mention of föo/test.py", ["föo/test.py"])
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert no error if multiple files have changed and are mentioned
+        commit_msg = "This is a test\n\nHere is a mention of föo/test.py\nAnd here is a mention of bar.txt"
+        commit = self.gitcommit(commit_msg, ["föo/test.py", "bar.txt"])
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert error if file has changed and is not mentioned
+        commit_msg = "This is a test\n\nHere is å mention of\nAnd here is a mention of bar.txt"
+        commit = self.gitcommit(commit_msg, ["föo/test.py", "bar.txt"])
+        violations = rule.validate(commit)
+        expected_violation = rules.RuleViolation("B7", "Body does not mention changed file 'föo/test.py'", None, 4)
+        self.assertEqual([expected_violation], violations)
+
+        # assert multiple errors if multiple files have changed and are not mentioned
+        commit_msg = "This is å test\n\nHere is a mention of\nAnd here is a mention of"
+        commit = self.gitcommit(commit_msg, ["föo/test.py", "bar.txt"])
+        violations = rule.validate(commit)
+        expected_violation_2 = rules.RuleViolation("B7", "Body does not mention changed file 'bar.txt'", None, 4)
+        self.assertEqual([expected_violation_2, expected_violation], violations)
+
+    def test_body_match_regex(self):
+        # We intentionally add 2 newlines at the end of our commit message as that's how git will pass the
+        # message. This way we also test that the rule strips off the last line.
+        commit = self.gitcommit("US1234: åbc\nIgnored\nBödy\nFöo\nMy-Commit-Tag: föo\n\n")
+
+        # assert no violation on default regex (=everything allowed)
+        rule = rules.BodyRegexMatches()
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert no violation on matching regex
+        # (also note that first body line - in between title and rest of body - is ignored)
+        rule = rules.BodyRegexMatches({"regex": "^Bödy(.*)"})
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert we can do end matching (and last empty line is ignored)
+        # (also note that first body line - in between title and rest of body - is ignored)
+        rule = rules.BodyRegexMatches({"regex": "My-Commit-Tag: föo$"})
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # common use-case: matching that a given line is present
+        rule = rules.BodyRegexMatches({"regex": "(.*)Föo(.*)"})
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # assert violation on non-matching body
+        rule = rules.BodyRegexMatches({"regex": "^Tëst(.*)Foo"})
+        violations = rule.validate(commit)
+        expected_violation = rules.RuleViolation("B8", "Body does not match regex (^Tëst(.*)Foo)", None, 6)
+        self.assertListEqual(violations, [expected_violation])
+
+        # assert no violation on None regex
+        rule = rules.BodyRegexMatches({"regex": None})
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # Assert no issues when there's no body or a weird body variation
+        bodies = ["åbc", "åbc\n", "åbc\nföo\n", "åbc\n\n", "åbc\nföo\nblå", "åbc\nföo\nblå\n"]
+        for body in bodies:
+            commit = self.gitcommit(body)
+            rule = rules.BodyRegexMatches({"regex": ".*"})
+            violations = rule.validate(commit)
+            self.assertIsNone(violations)
diff --git a/gitlint-core/gitlint/tests/rules/test_configuration_rules.py b/gitlint-core/gitlint/tests/rules/test_configuration_rules.py
new file mode 100644
index 0000000..5935a4a
--- /dev/null
+++ b/gitlint-core/gitlint/tests/rules/test_configuration_rules.py
@@ -0,0 +1,178 @@
+from gitlint import rules
+from gitlint.config import LintConfig
+from gitlint.tests.base import (
+    EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING,
+    BaseTestCase,
+)
+
+
+class ConfigurationRuleTests(BaseTestCase):
+    def test_ignore_by_title(self):
+        commit = self.gitcommit("Releäse\n\nThis is the secōnd body line")
+
+        # No regex specified -> Config shouldn't be changed
+        rule = rules.IgnoreByTitle()
+        config = LintConfig()
+        rule.apply(config, commit)
+        self.assertEqual(config, LintConfig())
+        self.assert_logged([])  # nothing logged -> nothing ignored
+
+        # Matching regex -> expect config to ignore all rules
+        rule = rules.IgnoreByTitle({"regex": "^Releäse(.*)"})
+        expected_config = LintConfig()
+        expected_config.ignore = "all"
+        rule.apply(config, commit)
+        self.assertEqual(config, expected_config)
+
+        expected_log_messages = [
+            EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING.format("I1", "ignore-by-title"),
+            "DEBUG: gitlint.rules Ignoring commit because of rule 'I1': "
+            "Commit title 'Releäse' matches the regex '^Releäse(.*)', ignoring rules: all",
+        ]
+        self.assert_logged(expected_log_messages)
+
+        # Matching regex with specific ignore
+        rule = rules.IgnoreByTitle({"regex": "^Releäse(.*)", "ignore": "T1,B2"})
+        expected_config = LintConfig()
+        expected_config.ignore = "T1,B2"
+        rule.apply(config, commit)
+        self.assertEqual(config, expected_config)
+
+        expected_log_messages += [
+            "DEBUG: gitlint.rules Ignoring commit because of rule 'I1': "
+            "Commit title 'Releäse' matches the regex '^Releäse(.*)', ignoring rules: T1,B2"
+        ]
+        self.assert_logged(expected_log_messages)
+
+    def test_ignore_by_body(self):
+        commit = self.gitcommit("Tïtle\n\nThis is\n a relëase body\n line")
+
+        # No regex specified -> Config shouldn't be changed
+        rule = rules.IgnoreByBody()
+        config = LintConfig()
+        rule.apply(config, commit)
+        self.assertEqual(config, LintConfig())
+        self.assert_logged([])  # nothing logged -> nothing ignored
+
+        # Matching regex -> expect config to ignore all rules
+        rule = rules.IgnoreByBody({"regex": "(.*)relëase(.*)"})
+        expected_config = LintConfig()
+        expected_config.ignore = "all"
+        rule.apply(config, commit)
+        self.assertEqual(config, expected_config)
+
+        expected_log_messages = [
+            EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING.format("I2", "ignore-by-body"),
+            "DEBUG: gitlint.rules Ignoring commit because of rule 'I2': "
+            "Commit message line ' a relëase body' matches the regex '(.*)relëase(.*)',"
+            " ignoring rules: all",
+        ]
+        self.assert_logged(expected_log_messages)
+
+        # Matching regex with specific ignore
+        rule = rules.IgnoreByBody({"regex": "(.*)relëase(.*)", "ignore": "T1,B2"})
+        expected_config = LintConfig()
+        expected_config.ignore = "T1,B2"
+        rule.apply(config, commit)
+        self.assertEqual(config, expected_config)
+
+        expected_log_messages += [
+            "DEBUG: gitlint.rules Ignoring commit because of rule 'I2': "
+            "Commit message line ' a relëase body' matches the regex '(.*)relëase(.*)', ignoring rules: T1,B2"
+        ]
+        self.assert_logged(expected_log_messages)
+
+    def test_ignore_by_author_name(self):
+        commit = self.gitcommit("Tïtle\n\nThis is\n a relëase body\n line", author_name="Tëst nåme")
+
+        # No regex specified -> Config shouldn't be changed
+        rule = rules.IgnoreByAuthorName()
+        config = LintConfig()
+        rule.apply(config, commit)
+        self.assertEqual(config, LintConfig())
+        self.assert_logged([])  # nothing logged -> nothing ignored
+
+        # No author available -> rule is skipped and warning logged
+        staged_commit = self.gitcommit("Tïtle\n\nThis is\n a relëase body\n line")
+        rule = rules.IgnoreByAuthorName({"regex": "foo"})
+        config = LintConfig()
+        rule.apply(config, staged_commit)
+        self.assertEqual(config, LintConfig())
+        expected_log_messages = [
+            "WARNING: gitlint.rules ignore-by-author-name - I4: skipping - commit.author_name unknown. "
+            "Suggested fix: Use the --staged flag (or set general.staged=True in .gitlint). "
+            "More details: https://jorisroovers.com/gitlint/configuration/#staged"
+        ]
+        self.assert_logged(expected_log_messages)
+
+        # Non-Matching regex -> expect config to stay the same
+        rule = rules.IgnoreByAuthorName({"regex": "foo"})
+        expected_config = LintConfig()
+        rule.apply(config, commit)
+        self.assertEqual(config, LintConfig())
+
+        # Matching regex -> expect config to ignore all rules
+        rule = rules.IgnoreByAuthorName({"regex": "(.*)ëst(.*)"})
+        expected_config = LintConfig()
+        expected_config.ignore = "all"
+        rule.apply(config, commit)
+        self.assertEqual(config, expected_config)
+
+        expected_log_messages += [
+            EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING.format("I4", "ignore-by-author-name"),
+            "DEBUG: gitlint.rules Ignoring commit because of rule 'I4': "
+            "Commit Author Name 'Tëst nåme' matches the regex '(.*)ëst(.*)',"
+            " ignoring rules: all",
+        ]
+        self.assert_logged(expected_log_messages)
+
+        # Matching regex with specific ignore
+        rule = rules.IgnoreByAuthorName({"regex": "(.*)nåme", "ignore": "T1,B2"})
+        expected_config = LintConfig()
+        expected_config.ignore = "T1,B2"
+        rule.apply(config, commit)
+        self.assertEqual(config, expected_config)
+
+        expected_log_messages += [
+            "DEBUG: gitlint.rules Ignoring commit because of rule 'I4': "
+            "Commit Author Name 'Tëst nåme' matches the regex '(.*)nåme', ignoring rules: T1,B2"
+        ]
+        self.assert_logged(expected_log_messages)
+
+    def test_ignore_body_lines(self):
+        commit1 = self.gitcommit("Tïtle\n\nThis is\n a relëase body\n line")
+        commit2 = self.gitcommit("Tïtle\n\nThis is\n a relëase body\n line")
+
+        # no regex specified, nothing should have happened:
+        # commit and config should remain identical, log should be empty
+        rule = rules.IgnoreBodyLines()
+        config = LintConfig()
+        rule.apply(config, commit1)
+        self.assertEqual(commit1, commit2)
+        self.assertEqual(config, LintConfig())
+        self.assert_logged([])
+
+        # Matching regex
+        rule = rules.IgnoreBodyLines({"regex": "(.*)relëase(.*)"})
+        config = LintConfig()
+        rule.apply(config, commit1)
+        # Our modified commit should be identical to a commit that doesn't contain the specific line
+        expected_commit = self.gitcommit("Tïtle\n\nThis is\n line")
+        # The original message isn't touched by this rule, this way we always have a way to reference back to it,
+        # so assert it's not modified by setting it to the same as commit1
+        expected_commit.message.original = commit1.message.original
+        self.assertEqual(commit1, expected_commit)
+        self.assertEqual(config, LintConfig())  # config shouldn't have been modified
+        expected_log_messages = [
+            EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING.format("I3", "ignore-body-lines"),
+            "DEBUG: gitlint.rules Ignoring line ' a relëase body' because it " + "matches '(.*)relëase(.*)'",
+        ]
+        self.assert_logged(expected_log_messages)
+
+        # Non-Matching regex: no changes expected
+        commit1 = self.gitcommit("Tïtle\n\nThis is\n a relëase body\n line")
+        rule = rules.IgnoreBodyLines({"regex": "(.*)föobar(.*)"})
+        config = LintConfig()
+        rule.apply(config, commit1)
+        self.assertEqual(commit1, commit2)
+        self.assertEqual(config, LintConfig())  # config shouldn't have been modified
diff --git a/gitlint-core/gitlint/tests/rules/test_meta_rules.py b/gitlint-core/gitlint/tests/rules/test_meta_rules.py
new file mode 100644
index 0000000..a574aa3
--- /dev/null
+++ b/gitlint-core/gitlint/tests/rules/test_meta_rules.py
@@ -0,0 +1,80 @@
+from gitlint.rules import AuthorValidEmail, RuleViolation
+from gitlint.tests.base import (
+    EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING,
+    BaseTestCase,
+)
+
+
+class MetaRuleTests(BaseTestCase):
+    def test_author_valid_email_rule(self):
+        rule = AuthorValidEmail()
+
+        # valid email addresses
+        valid_email_addresses = [
+            "föo@bar.com",
+            "Jöhn.Doe@bar.com",
+            "jöhn+doe@bar.com",
+            "jöhn/doe@bar.com",
+            "jöhn.doe@subdomain.bar.com",
+        ]
+        for email in valid_email_addresses:
+            commit = self.gitcommit("", author_email=email)
+            violations = rule.validate(commit)
+            self.assertIsNone(violations)
+
+        # No email address (=allowed for now, as gitlint also lints messages passed via stdin that don't have an
+        # email address)
+        commit = self.gitcommit("")
+        violations = rule.validate(commit)
+        self.assertIsNone(violations)
+
+        # Invalid email addresses: no TLD, no domain, no @, space anywhere (=valid but not allowed by gitlint)
+        invalid_email_addresses = [
+            "föo@bar",
+            "JöhnDoe",
+            "Jöhn Doe",
+            "Jöhn Doe@foo.com",
+            " JöhnDoe@foo.com",
+            "JöhnDoe@ foo.com",
+            "JöhnDoe@foo. com",
+            "JöhnDoe@foo. com",
+            "@bår.com",
+            "föo@.com",
+        ]
+        for email in invalid_email_addresses:
+            commit = self.gitcommit("", author_email=email)
+            violations = rule.validate(commit)
+            self.assertListEqual(violations, [RuleViolation("M1", "Author email for commit is invalid", email)])
+
+        # Ensure nothing is logged, this relates specifically to a deprecation warning on the use of
+        # re.match vs re.search in the rules (see issue #254)
+        # If no custom regex is used, the rule uses the default regex in combination with re.search
+        self.assert_logged([])
+
+    def test_author_valid_email_rule_custom_regex(self):
+        # regex=None -> the rule isn't applied
+        rule = AuthorValidEmail()
+        rule.options["regex"].set(None)
+        emailadresses = ["föo", None, "hür dür"]
+        for email in emailadresses:
+            commit = self.gitcommit("", author_email=email)
+            violations = rule.validate(commit)
+            self.assertIsNone(violations)
+
+        # Custom domain
+        rule = AuthorValidEmail({"regex": "[^@]+@bår.com"})
+        valid_email_addresses = ["föo@bår.com", "Jöhn.Doe@bår.com", "jöhn+doe@bår.com", "jöhn/doe@bår.com"]
+        for email in valid_email_addresses:
+            commit = self.gitcommit("", author_email=email)
+            violations = rule.validate(commit)
+            self.assertIsNone(violations)
+
+        # Invalid email addresses
+        invalid_email_addresses = ["föo@hur.com"]
+        for email in invalid_email_addresses:
+            commit = self.gitcommit("", author_email=email)
+            violations = rule.validate(commit)
+            self.assertListEqual(violations, [RuleViolation("M1", "Author email for commit is invalid", email)])
+
+        # When a custom regex is used, a warning should be logged by default
+        self.assert_logged([EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING.format("M1", "author-valid-email")])
diff --git a/gitlint-core/gitlint/tests/rules/test_rules.py b/gitlint-core/gitlint/tests/rules/test_rules.py
new file mode 100644
index 0000000..b401372
--- /dev/null
+++ b/gitlint-core/gitlint/tests/rules/test_rules.py
@@ -0,0 +1,32 @@
+from gitlint.rules import Rule, RuleViolation
+from gitlint.tests.base import BaseTestCase
+
+
+class RuleTests(BaseTestCase):
+    def test_ruleviolation__str__(self):
+        expected = '57: rule-ïd Tēst message: "Tēst content"'
+        self.assertEqual(str(RuleViolation("rule-ïd", "Tēst message", "Tēst content", 57)), expected)
+
+    def test_rule_equality(self):
+        self.assertEqual(Rule(), Rule())
+        # Ensure rules are not equal if they differ on their attributes
+        for attr in ["id", "name", "target", "options"]:
+            rule = Rule()
+            setattr(rule, attr, "åbc")
+            self.assertNotEqual(Rule(), rule)
+
+    def test_rule_log(self):
+        rule = Rule()
+        self.assertIsNone(rule._log)
+        rule.log.debug("Tēst message")
+        self.assert_log_contains("DEBUG: gitlint.rules Tēst message")
+
+        # Assert the same logger is reused when logging multiple messages
+        log = rule._log
+        rule.log.debug("Anöther message")
+        self.assertEqual(log, rule._log)
+        self.assert_log_contains("DEBUG: gitlint.rules Anöther message")
+
+    def test_rule_violation_equality(self):
+        violation1 = RuleViolation("ïd1", "My messåge", "My cöntent", 1)
+        self.object_equality_test(violation1, ["rule_id", "message", "content", "line_nr"])
diff --git a/gitlint-core/gitlint/tests/rules/test_title_rules.py b/gitlint-core/gitlint/tests/rules/test_title_rules.py
new file mode 100644
index 0000000..cba3851
--- /dev/null
+++ b/gitlint-core/gitlint/tests/rules/test_title_rules.py
@@ -0,0 +1,200 @@
+from gitlint.rules import (
+    RuleViolation,
+    TitleHardTab,
+    TitleLeadingWhitespace,
+    TitleMaxLength,
+    TitleMinLength,
+    TitleMustNotContainWord,
+    TitleRegexMatches,
+    TitleTrailingPunctuation,
+    TitleTrailingWhitespace,
+)
+from gitlint.tests.base import BaseTestCase
+
+
+class TitleRuleTests(BaseTestCase):
+    def test_max_line_length(self):
+        rule = TitleMaxLength()
+
+        # assert no error
+        violation = rule.validate("å" * 72, None)
+        self.assertIsNone(violation)
+
+        # assert error on line length > 72
+        expected_violation = RuleViolation("T1", "Title exceeds max length (73>72)", "å" * 73)
+        violations = rule.validate("å" * 73, None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # set line length to 120, and check no violation on length 73
+        rule = TitleMaxLength({"line-length": 120})
+        violations = rule.validate("å" * 73, None)
+        self.assertIsNone(violations)
+
+        # assert raise on 121
+        expected_violation = RuleViolation("T1", "Title exceeds max length (121>120)", "å" * 121)
+        violations = rule.validate("å" * 121, None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_trailing_whitespace(self):
+        rule = TitleTrailingWhitespace()
+
+        # assert no error
+        violations = rule.validate("å", None)
+        self.assertIsNone(violations)
+
+        # trailing space
+        expected_violation = RuleViolation("T2", "Title has trailing whitespace", "å ")
+        violations = rule.validate("å ", None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # trailing tab
+        expected_violation = RuleViolation("T2", "Title has trailing whitespace", "å\t")
+        violations = rule.validate("å\t", None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_hard_tabs(self):
+        rule = TitleHardTab()
+
+        # assert no error
+        violations = rule.validate("This is å test", None)
+        self.assertIsNone(violations)
+
+        # contains hard tab
+        expected_violation = RuleViolation("T4", "Title contains hard tab characters (\\t)", "This is å\ttest")
+        violations = rule.validate("This is å\ttest", None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_trailing_punctuation(self):
+        rule = TitleTrailingPunctuation()
+
+        # assert no error
+        violations = rule.validate("This is å test", None)
+        self.assertIsNone(violations)
+
+        # assert errors for different punctuations
+        punctuation = "?:!.,;"
+        for char in punctuation:
+            line = "This is å test" + char  # note that make sure to include some unicode!
+            gitcontext = self.gitcontext(line)
+            expected_violation = RuleViolation("T3", f"Title has trailing punctuation ({char})", line)
+            violations = rule.validate(line, gitcontext)
+            self.assertListEqual(violations, [expected_violation])
+
+    def test_title_must_not_contain_word(self):
+        rule = TitleMustNotContainWord()
+
+        # no violations
+        violations = rule.validate("This is å test", None)
+        self.assertIsNone(violations)
+
+        # no violation if WIP occurs inside a word
+        violations = rule.validate("This is å wiping test", None)
+        self.assertIsNone(violations)
+
+        # match literally
+        violations = rule.validate("WIP This is å test", None)
+        expected_violation = RuleViolation(
+            "T5", "Title contains the word 'WIP' (case-insensitive)", "WIP This is å test"
+        )
+        self.assertListEqual(violations, [expected_violation])
+
+        # match case insensitive
+        violations = rule.validate("wip This is å test", None)
+        expected_violation = RuleViolation(
+            "T5", "Title contains the word 'WIP' (case-insensitive)", "wip This is å test"
+        )
+        self.assertListEqual(violations, [expected_violation])
+
+        # match if there is a colon after the word
+        violations = rule.validate("WIP:This is å test", None)
+        expected_violation = RuleViolation(
+            "T5", "Title contains the word 'WIP' (case-insensitive)", "WIP:This is å test"
+        )
+        self.assertListEqual(violations, [expected_violation])
+
+        # match multiple words
+        rule = TitleMustNotContainWord({"words": "wip,test,å"})
+        violations = rule.validate("WIP:This is å test", None)
+        expected_violation = RuleViolation(
+            "T5", "Title contains the word 'wip' (case-insensitive)", "WIP:This is å test"
+        )
+        expected_violation2 = RuleViolation(
+            "T5", "Title contains the word 'test' (case-insensitive)", "WIP:This is å test"
+        )
+        expected_violation3 = RuleViolation(
+            "T5", "Title contains the word 'å' (case-insensitive)", "WIP:This is å test"
+        )
+        self.assertListEqual(violations, [expected_violation, expected_violation2, expected_violation3])
+
+    def test_leading_whitespace(self):
+        rule = TitleLeadingWhitespace()
+
+        # assert no error
+        violations = rule.validate("a", None)
+        self.assertIsNone(violations)
+
+        # leading space
+        expected_violation = RuleViolation("T6", "Title has leading whitespace", " a")
+        violations = rule.validate(" a", None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # leading tab
+        expected_violation = RuleViolation("T6", "Title has leading whitespace", "\ta")
+        violations = rule.validate("\ta", None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # unicode test
+        expected_violation = RuleViolation("T6", "Title has leading whitespace", " ☺")
+        violations = rule.validate(" ☺", None)
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_regex_matches(self):
+        commit = self.gitcommit("US1234: åbc\n")
+
+        # assert no violation on default regex (=everything allowed)
+        rule = TitleRegexMatches()
+        violations = rule.validate(commit.message.title, commit)
+        self.assertIsNone(violations)
+
+        # assert no violation on matching regex
+        rule = TitleRegexMatches({"regex": "^US[0-9]*: å"})
+        violations = rule.validate(commit.message.title, commit)
+        self.assertIsNone(violations)
+
+        # assert violation when no matching regex
+        rule = TitleRegexMatches({"regex": "^UÅ[0-9]*"})
+        violations = rule.validate(commit.message.title, commit)
+        expected_violation = RuleViolation("T7", "Title does not match regex (^UÅ[0-9]*)", "US1234: åbc")
+        self.assertListEqual(violations, [expected_violation])
+
+    def test_min_line_length(self):
+        rule = TitleMinLength()
+
+        # assert no error
+        violation = rule.validate("å" * 72, None)
+        self.assertIsNone(violation)
+
+        # assert error on line length < 5
+        expected_violation = RuleViolation("T8", "Title is too short (4<5)", "å" * 4, 1)
+        violations = rule.validate("å" * 4, None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # set line length to 3, and check no violation on length 4
+        rule = TitleMinLength({"min-length": 3})
+        violations = rule.validate("å" * 4, None)
+        self.assertIsNone(violations)
+
+        # assert no violations on length 3 (this asserts we've implemented a *strict* less than)
+        rule = TitleMinLength({"min-length": 3})
+        violations = rule.validate("å" * 3, None)
+        self.assertIsNone(violations)
+
+        # assert raise on 2
+        expected_violation = RuleViolation("T8", "Title is too short (2<3)", "å" * 2, 1)
+        violations = rule.validate("å" * 2, None)
+        self.assertListEqual(violations, [expected_violation])
+
+        # assert raise on empty title
+        expected_violation = RuleViolation("T8", "Title is too short (0<3)", "", 1)
+        violations = rule.validate("", None)
+        self.assertListEqual(violations, [expected_violation])
diff --git a/gitlint-core/gitlint/tests/rules/test_user_rules.py b/gitlint-core/gitlint/tests/rules/test_user_rules.py
new file mode 100644
index 0000000..8086bea
--- /dev/null
+++ b/gitlint-core/gitlint/tests/rules/test_user_rules.py
@@ -0,0 +1,266 @@
+import os
+import sys
+
+from gitlint import options, rules
+from gitlint.rule_finder import assert_valid_rule_class, find_rule_classes
+from gitlint.rules import UserRuleError
+from gitlint.tests.base import BaseTestCase
+
+
+class UserRuleTests(BaseTestCase):
+    def test_find_rule_classes(self):
+        # Let's find some user classes!
+        user_rule_path = self.get_sample_path("user_rules")
+        classes = find_rule_classes(user_rule_path)
+
+        # Compare string representations because we can't import MyUserCommitRule here since samples/user_rules is not
+        # a proper python package
+        # Note that the following check effectively asserts that:
+        # - There is only 1 rule recognized and it is MyUserCommitRule
+        # - Other non-python files in the directory are ignored
+        # - Other members of the my_commit_rules module are ignored
+        #  (such as func_should_be_ignored, global_variable_should_be_ignored)
+        # - Rules are loaded non-recursively (user_rules/import_exception directory is ignored)
+        self.assertEqual("[<class 'my_commit_rules.MyUserCommitRule'>]", str(classes))
+
+        # Assert that we added the new user_rules directory to the system path and modules
+        self.assertIn(user_rule_path, sys.path)
+        self.assertIn("my_commit_rules", sys.modules)
+
+        # Do some basic asserts on our user rule
+        self.assertEqual(classes[0].id, "UC1")
+        self.assertEqual(classes[0].name, "my-üser-commit-rule")
+        expected_option = options.IntOption("violation-count", 1, "Number of violåtions to return")
+        self.assertListEqual(classes[0].options_spec, [expected_option])
+        self.assertTrue(hasattr(classes[0], "validate"))
+
+        # Test that we can instantiate the class and can execute run the validate method and that it returns the
+        # expected result
+        rule_class = classes[0]()
+        violations = rule_class.validate("false-commit-object (ignored)")
+        self.assertListEqual(violations, [rules.RuleViolation("UC1", "Commit violåtion 1", "Contënt 1", 1)])
+
+        # Have it return more violations
+        rule_class.options["violation-count"].value = 2
+        violations = rule_class.validate("false-commit-object (ignored)")
+        self.assertListEqual(
+            violations,
+            [
+                rules.RuleViolation("UC1", "Commit violåtion 1", "Contënt 1", 1),
+                rules.RuleViolation("UC1", "Commit violåtion 2", "Contënt 2", 2),
+            ],
+        )
+
+    def test_extra_path_specified_by_file(self):
+        # Test that find_rule_classes can handle an extra path given as a file name instead of a directory
+        user_rule_path = self.get_sample_path("user_rules")
+        user_rule_module = os.path.join(user_rule_path, "my_commit_rules.py")
+        classes = find_rule_classes(user_rule_module)
+
+        rule_class = classes[0]()
+        violations = rule_class.validate("false-commit-object (ignored)")
+        self.assertListEqual(violations, [rules.RuleViolation("UC1", "Commit violåtion 1", "Contënt 1", 1)])
+
+    def test_rules_from_init_file(self):
+        # Test that we can import rules that are defined in __init__.py files
+        # This also tests that we can import rules from python packages. This use to cause issues with pypy
+        # So this is also a regression test for that.
+        user_rule_path = self.get_sample_path(os.path.join("user_rules", "parent_package"))
+        classes = find_rule_classes(user_rule_path)
+
+        # convert classes to strings and sort them so we can compare them
+        class_strings = sorted(str(clazz) for clazz in classes)
+        expected = ["<class 'my_commit_rules.MyUserCommitRule'>", "<class 'parent_package.InitFileRule'>"]
+        self.assertListEqual(class_strings, expected)
+
+    def test_empty_user_classes(self):
+        # Test that we don't find rules if we scan a different directory
+        user_rule_path = self.get_sample_path("config")
+        classes = find_rule_classes(user_rule_path)
+        self.assertListEqual(classes, [])
+
+        # Importantly, ensure that the directory is not added to the syspath as this happens only when we actually
+        # find modules
+        self.assertNotIn(user_rule_path, sys.path)
+
+    def test_failed_module_import(self):
+        # test importing a bogus module
+        user_rule_path = self.get_sample_path("user_rules/import_exception")
+        # We don't check the entire error message because that is different based on the python version and underlying
+        # operating system
+        expected_msg = "Error while importing extra-path module 'invalid_python'"
+        with self.assertRaisesRegex(UserRuleError, expected_msg):
+            find_rule_classes(user_rule_path)
+
+    def test_find_rule_classes_nonexisting_path(self):
+        with self.assertRaisesMessage(UserRuleError, "Invalid extra-path: föo/bar"):
+            find_rule_classes("föo/bar")
+
+    def test_assert_valid_rule_class(self):
+        class MyLineRuleClass(rules.LineRule):
+            id = "UC1"
+            name = "my-lïne-rule"
+            target = rules.CommitMessageTitle
+
+            def validate(self):
+                pass  # pragma: nocover
+
+        class MyCommitRuleClass(rules.CommitRule):
+            id = "UC2"
+            name = "my-cömmit-rule"
+
+            def validate(self):
+                pass  # pragma: nocover
+
+        class MyConfigurationRuleClass(rules.ConfigurationRule):
+            id = "UC3"
+            name = "my-cönfiguration-rule"
+
+            def apply(self):
+                pass  # pragma: nocover
+
+        # Just assert that no error is raised
+        self.assertIsNone(assert_valid_rule_class(MyLineRuleClass))
+        self.assertIsNone(assert_valid_rule_class(MyCommitRuleClass))
+        self.assertIsNone(assert_valid_rule_class(MyConfigurationRuleClass))
+
+    def test_assert_valid_rule_class_negative(self):
+        # general test to make sure that incorrect rules will raise an exception
+        user_rule_path = self.get_sample_path("user_rules/incorrect_linerule")
+        with self.assertRaisesMessage(
+            UserRuleError, "User-defined rule class 'MyUserLineRule' must have a 'validate' method"
+        ):
+            find_rule_classes(user_rule_path)
+
+    def test_assert_valid_rule_class_negative_parent(self):
+        # rule class must extend from LineRule or CommitRule
+        class MyRuleClass:
+            pass
+
+        expected_msg = (
+            "User-defined rule class 'MyRuleClass' must extend from gitlint.rules.LineRule, "
+            "gitlint.rules.CommitRule or gitlint.rules.ConfigurationRule"
+        )
+        with self.assertRaisesMessage(UserRuleError, expected_msg):
+            assert_valid_rule_class(MyRuleClass)
+
+    def test_assert_valid_rule_class_negative_id(self):
+        for parent_class in [rules.LineRule, rules.CommitRule]:
+
+            class MyRuleClass(parent_class):
+                pass
+
+            # Rule class must have an id
+            expected_msg = "User-defined rule class 'MyRuleClass' must have an 'id' attribute"
+            with self.assertRaisesMessage(UserRuleError, expected_msg):
+                assert_valid_rule_class(MyRuleClass)
+
+            # Rule ids must be non-empty
+            MyRuleClass.id = ""
+            with self.assertRaisesMessage(UserRuleError, expected_msg):
+                assert_valid_rule_class(MyRuleClass)
+
+            # Rule ids must not start with one of the reserved id letters
+            for letter in ["T", "R", "B", "M", "I"]:
+                MyRuleClass.id = letter + "1"
+                expected_msg = (
+                    f"The id '{letter}' of 'MyRuleClass' is invalid. Gitlint reserves ids starting with R,T,B,M,I"
+                )
+                with self.assertRaisesMessage(UserRuleError, expected_msg):
+                    assert_valid_rule_class(MyRuleClass)
+
+    def test_assert_valid_rule_class_negative_name(self):
+        for parent_class in [rules.LineRule, rules.CommitRule]:
+
+            class MyRuleClass(parent_class):
+                id = "UC1"
+
+            # Rule class must have a name
+            expected_msg = "User-defined rule class 'MyRuleClass' must have a 'name' attribute"
+            with self.assertRaisesMessage(UserRuleError, expected_msg):
+                assert_valid_rule_class(MyRuleClass)
+
+            # Rule names must be non-empty
+            MyRuleClass.name = ""
+            with self.assertRaisesMessage(UserRuleError, expected_msg):
+                assert_valid_rule_class(MyRuleClass)
+
+    def test_assert_valid_rule_class_negative_option_spec(self):
+        for parent_class in [rules.LineRule, rules.CommitRule]:
+
+            class MyRuleClass(parent_class):
+                id = "UC1"
+                name = "my-rüle-class"
+
+            # if set, option_spec must be a list of gitlint options
+            MyRuleClass.options_spec = "föo"
+            expected_msg = (
+                "The options_spec attribute of user-defined rule class 'MyRuleClass' must be a list "
+                "of gitlint.options.RuleOption"
+            )
+            with self.assertRaisesMessage(UserRuleError, expected_msg):
+                assert_valid_rule_class(MyRuleClass)
+
+            # option_spec is a list, but not of gitlint options
+            MyRuleClass.options_spec = ["föo", 123]
+            with self.assertRaisesMessage(UserRuleError, expected_msg):
+                assert_valid_rule_class(MyRuleClass)
+
+    def test_assert_valid_rule_class_negative_validate(self):
+        baseclasses = [rules.LineRule, rules.CommitRule]
+        for clazz in baseclasses:
+
+            class MyRuleClass(clazz):
+                id = "UC1"
+                name = "my-rüle-class"
+
+            with self.assertRaisesMessage(
+                UserRuleError, "User-defined rule class 'MyRuleClass' must have a 'validate' method"
+            ):
+                assert_valid_rule_class(MyRuleClass)
+
+            # validate attribute - not a method
+            MyRuleClass.validate = "föo"
+            with self.assertRaisesMessage(
+                UserRuleError, "User-defined rule class 'MyRuleClass' must have a 'validate' method"
+            ):
+                assert_valid_rule_class(MyRuleClass)
+
+    def test_assert_valid_rule_class_negative_apply(self):
+        class MyRuleClass(rules.ConfigurationRule):
+            id = "UCR1"
+            name = "my-rüle-class"
+
+        expected_msg = "User-defined Configuration rule class 'MyRuleClass' must have an 'apply' method"
+        with self.assertRaisesMessage(UserRuleError, expected_msg):
+            assert_valid_rule_class(MyRuleClass)
+
+        # apply attribute - not a method
+        MyRuleClass.apply = "föo"
+        with self.assertRaisesMessage(UserRuleError, expected_msg):
+            assert_valid_rule_class(MyRuleClass)
+
+    def test_assert_valid_rule_class_negative_target(self):
+        class MyRuleClass(rules.LineRule):
+            id = "UC1"
+            name = "my-rüle-class"
+
+            def validate(self):
+                pass  # pragma: nocover
+
+        # no target
+        expected_msg = (
+            "The target attribute of the user-defined LineRule class 'MyRuleClass' must be either "
+            "gitlint.rules.CommitMessageTitle or gitlint.rules.CommitMessageBody"
+        )
+        with self.assertRaisesMessage(UserRuleError, expected_msg):
+            assert_valid_rule_class(MyRuleClass)
+
+        # invalid target
+        MyRuleClass.target = "föo"
+        with self.assertRaisesMessage(UserRuleError, expected_msg):
+            assert_valid_rule_class(MyRuleClass)
+
+        # valid target, no exception should be raised
+        MyRuleClass.target = rules.CommitMessageTitle
+        self.assertIsNone(assert_valid_rule_class(MyRuleClass))
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/fixup b/gitlint-core/gitlint/tests/samples/commit_message/fixup
new file mode 100644
index 0000000..2539dd1
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/fixup
@@ -0,0 +1 @@
+fixup! WIP: This is a fixup cömmit with violations.
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/fixup_amend b/gitlint-core/gitlint/tests/samples/commit_message/fixup_amend
new file mode 100644
index 0000000..293a2b7
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/fixup_amend
@@ -0,0 +1 @@
+amend! WIP: This is a fixup cömmit with violations.
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/merge b/gitlint-core/gitlint/tests/samples/commit_message/merge
new file mode 100644
index 0000000..764e131
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/merge
@@ -0,0 +1,3 @@
+Merge: "This is a merge commit with a long title that most definitely exceeds the normål limit of 72 chars"
+This line should be ëmpty
+This is the first line is meant to test å line that exceeds the maximum line length of 80 characters.
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/no-violations b/gitlint-core/gitlint/tests/samples/commit_message/no-violations
new file mode 100644
index 0000000..33c73b9
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/no-violations
@@ -0,0 +1,6 @@
+Normal Commit Tïtle
+
+Nörmal body that contains a few lines of text describing the changes in the
+commit without violating any of gitlint's rules.
+
+Sïgned-Off-By: foo@bar.com
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/revert b/gitlint-core/gitlint/tests/samples/commit_message/revert
new file mode 100644
index 0000000..6dc8368
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/revert
@@ -0,0 +1,3 @@
+Revert "WIP: this is a tïtle"
+
+This reverts commit a8ad67e04164a537198dea94a4fde81c5592ae9c.
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/sample1 b/gitlint-core/gitlint/tests/samples/commit_message/sample1
new file mode 100644
index 0000000..646c0cb
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/sample1
@@ -0,0 +1,14 @@
+Commit title contåining 'WIP', as well as trailing punctuation.
+This line should be empty
+This is the first line of the commit message body and it is meant to test a line that exceeds the maximum line length of 80 characters.
+This line has a tråiling space. 
+This line has a trailing tab.	
+# This is a cömmented  line
+# ------------------------ >8 ------------------------
+# Anything after this line should be cleaned up
+# this line appears on `git commit -v` command
+diff --git a/gitlint/tests/samples/commit_message/sample1 b/gitlint/tests/samples/commit_message/sample1
+index 82dbe7f..ae71a14 100644
+--- a/gitlint/tests/samples/commit_message/sample1
++++ b/gitlint/tests/samples/commit_message/sample1
+@@ -1 +1 @@
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/sample2 b/gitlint-core/gitlint/tests/samples/commit_message/sample2
new file mode 100644
index 0000000..356540c
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/sample2
@@ -0,0 +1 @@
+Just a title contåining WIP
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/sample3 b/gitlint-core/gitlint/tests/samples/commit_message/sample3
new file mode 100644
index 0000000..d67d70b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/sample3
@@ -0,0 +1,6 @@
+ Commit title containing 'WIP', 	leading and tråiling whitespace and longer than 72 characters.
+This line should be empty
+This is the first line is meånt to test a line that exceeds the maximum line length of 80 characters.
+This line has a trailing space. 
+This line has a tråiling tab.	
+# This is a commented  line
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/sample4 b/gitlint-core/gitlint/tests/samples/commit_message/sample4
new file mode 100644
index 0000000..c858d89
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/sample4
@@ -0,0 +1,7 @@
+ Commit title containing 'WIP', 	leading and tråiling whitespace and longer than 72 characters.
+This line should be empty
+This is the first line is meånt to test a line that exceeds the maximum line length of 80 characters.
+This line has a tråiling space.
+This line has a trailing tab.	
+# This is a commented  line
+gitlint-ignore: all
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/sample5 b/gitlint-core/gitlint/tests/samples/commit_message/sample5
new file mode 100644
index 0000000..77ccbe8
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/sample5
@@ -0,0 +1,7 @@
+ Commit title containing 'WIP', 	leading and tråiling whitespace and longer than 72 characters.
+This line should be ëmpty
+This is the first line is meånt to test a line that exceeds the maximum line length of 80 characters.
+This line has a tråiling space. 
+This line has a trailing tab.	
+# This is a commented  line
+gitlint-ignore: T3, T6, body-max-line-length
diff --git a/gitlint-core/gitlint/tests/samples/commit_message/squash b/gitlint-core/gitlint/tests/samples/commit_message/squash
new file mode 100644
index 0000000..538a93a
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/commit_message/squash
@@ -0,0 +1,3 @@
+squash! WIP: This is a squash cömmit with violations.
+
+Body töo short
diff --git a/gitlint-core/gitlint/tests/samples/config/AUTHORS b/gitlint-core/gitlint/tests/samples/config/AUTHORS
new file mode 100644
index 0000000..1c355d6
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/AUTHORS
@@ -0,0 +1,2 @@
+John Doe <john.doe@mail.com>
+Bob Smith <bob.smith@mail.com>
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/config/gitlintconfig b/gitlint-core/gitlint/tests/samples/config/gitlintconfig
new file mode 100644
index 0000000..8c93f71
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/gitlintconfig
@@ -0,0 +1,15 @@
+[general]
+ignore=title-trailing-whitespace,B2
+verbosity = 1
+ignore-merge-commits = false
+debug = false
+
+[title-max-length]
+line-length=20
+
+[B1]
+# B1 = body-max-line-length
+line-length=30
+
+[title-must-not-contain-word]
+words=WIP,bögus
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/config/invalid-option-value b/gitlint-core/gitlint/tests/samples/config/invalid-option-value
new file mode 100644
index 0000000..92015aa
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/invalid-option-value
@@ -0,0 +1,11 @@
+[general]
+ignore=title-trailing-whitespace,B2
+verbosity = 1
+
+[title-max-length]
+line-length=föo
+
+
+[B1]
+# B1 = body-max-line-length
+line-length=30
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/config/named-rules b/gitlint-core/gitlint/tests/samples/config/named-rules
new file mode 100644
index 0000000..73ab0d2
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/named-rules
@@ -0,0 +1,8 @@
+[title-must-not-contain-word]
+words=WIP,bögus
+
+[title-must-not-contain-word:extra-wörds]
+words=hür,tëst
+
+[T5:even-more-wörds]
+words=hür,tïtle
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/config/no-sections b/gitlint-core/gitlint/tests/samples/config/no-sections
new file mode 100644
index 0000000..ec82b25
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/no-sections
@@ -0,0 +1 @@
+ignore=title-max-length, T3
diff --git a/gitlint-core/gitlint/tests/samples/config/nonexisting-general-option b/gitlint-core/gitlint/tests/samples/config/nonexisting-general-option
new file mode 100644
index 0000000..d5cfef2
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/nonexisting-general-option
@@ -0,0 +1,13 @@
+[general]
+ignore=title-trailing-whitespace,B2
+verbosity = 1
+ignore-merge-commits = false
+foo = bar
+
+[title-max-length]
+line-length=20
+
+
+[B1]
+# B1 = body-max-line-length
+line-length=30
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/config/nonexisting-option b/gitlint-core/gitlint/tests/samples/config/nonexisting-option
new file mode 100644
index 0000000..6964c77
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/nonexisting-option
@@ -0,0 +1,11 @@
+[general]
+ignore=title-trailing-whitespace,B2
+verbosity = 1
+
+[title-max-length]
+föobar=foo
+
+
+[B1]
+# B1 = body-max-line-length
+line-length=30
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/config/nonexisting-rule b/gitlint-core/gitlint/tests/samples/config/nonexisting-rule
new file mode 100644
index 0000000..c0f0d2b
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/config/nonexisting-rule
@@ -0,0 +1,11 @@
+[general]
+ignore=title-trailing-whitespace,B2
+verbosity = 1
+
+[föobar]
+line-length=20
+
+
+[B1]
+# B1 = body-max-line-length
+line-length=30
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/bogus-file.txt b/gitlint-core/gitlint/tests/samples/user_rules/bogus-file.txt
new file mode 100644
index 0000000..2a56650
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/bogus-file.txt
@@ -0,0 +1,2 @@
+This is just a bogus file.
+This file being here is part of the test: gitlint should ignore it.
\ No newline at end of file
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/import_exception/invalid_python.py b/gitlint-core/gitlint/tests/samples/user_rules/import_exception/invalid_python.py
new file mode 100644
index 0000000..a123a64
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/import_exception/invalid_python.py
@@ -0,0 +1,2 @@
+# This is invalid python code which will cause an import exception
+class MyObject:
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/incorrect_linerule/my_line_rule.py b/gitlint-core/gitlint/tests/samples/user_rules/incorrect_linerule/my_line_rule.py
new file mode 100644
index 0000000..b23b5bf
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/incorrect_linerule/my_line_rule.py
@@ -0,0 +1,8 @@
+from gitlint.rules import LineRule
+
+
+class MyUserLineRule(LineRule):
+    id = "UC2"
+    name = "my-lïne-rule"
+
+    # missing validate method, missing target attribute
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.foo b/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.foo
new file mode 100644
index 0000000..605d704
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.foo
@@ -0,0 +1,16 @@
+# This rule is ignored because it doesn't have a .py extension
+from gitlint.rules import CommitRule, RuleViolation
+from gitlint.options import IntOption
+
+
+class MyUserCommitRule2(CommitRule):
+    name = "my-user-commit-rule2"
+    id = "TUC2"
+    options_spec = [IntOption('violation-count', 0, "Number of violations to return")]
+
+    def validate(self, _commit):
+        violations = []
+        for i in range(1, self.options['violation-count'].value + 1):
+            violations.append(RuleViolation(self.id, "Commit violation %d" % i, "Content %d" % i, i))
+
+        return violations
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.py b/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.py
new file mode 100644
index 0000000..c947250
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.py
@@ -0,0 +1,25 @@
+from gitlint.options import IntOption
+from gitlint.rules import CommitRule, RuleViolation
+
+
+class MyUserCommitRule(CommitRule):
+    name = "my-üser-commit-rule"
+    id = "UC1"
+    options_spec = [IntOption("violation-count", 1, "Number of violåtions to return")]
+
+    def validate(self, _commit):
+        violations = []
+        for i in range(1, self.options["violation-count"].value + 1):
+            violations.append(RuleViolation(self.id, "Commit violåtion %d" % i, "Contënt %d" % i, i))
+
+        return violations
+
+
+# The below code is present so that we can test that we actually ignore it
+
+
+def func_should_be_ignored():
+    pass  # pragma: nocover
+
+
+global_variable_should_be_ignored = True
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/parent_package/__init__.py b/gitlint-core/gitlint/tests/samples/user_rules/parent_package/__init__.py
new file mode 100644
index 0000000..c2863fe
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/parent_package/__init__.py
@@ -0,0 +1,12 @@
+# This file is meant to test that we can also load rules from __init__.py files, this was an issue with pypy before.
+
+from gitlint.rules import CommitRule
+
+
+class InitFileRule(CommitRule):
+    name = "my-init-cömmit-rule"
+    id = "UC1"
+    options_spec = []
+
+    def validate(self, _commit):
+        return []  # pragma: nocover
diff --git a/gitlint-core/gitlint/tests/samples/user_rules/parent_package/my_commit_rules.py b/gitlint-core/gitlint/tests/samples/user_rules/parent_package/my_commit_rules.py
new file mode 100644
index 0000000..f91cb07
--- /dev/null
+++ b/gitlint-core/gitlint/tests/samples/user_rules/parent_package/my_commit_rules.py
@@ -0,0 +1,10 @@
+from gitlint.rules import CommitRule
+
+
+class MyUserCommitRule(CommitRule):
+    name = "my-user-cömmit-rule"
+    id = "UC2"
+    options_spec = []
+
+    def validate(self, _commit):
+        return []
diff --git a/gitlint-core/gitlint/tests/test_cache.py b/gitlint-core/gitlint/tests/test_cache.py
new file mode 100644
index 0000000..08b821e
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_cache.py
@@ -0,0 +1,55 @@
+from gitlint.cache import PropertyCache, cache
+from gitlint.tests.base import BaseTestCase
+
+
+class CacheTests(BaseTestCase):
+    class MyClass(PropertyCache):
+        """Simple class that has cached properties, used for testing."""
+
+        def __init__(self):
+            PropertyCache.__init__(self)
+            self.counter = 0
+
+        @property
+        @cache
+        def foo(self):
+            self.counter += 1
+            return "bår"
+
+        @property
+        @cache(cachekey="hür")
+        def bar(self):
+            self.counter += 1
+            return "fōo"
+
+    def test_cache(self):
+        # Init new class with cached properties
+        myclass = self.MyClass()
+        self.assertEqual(myclass.counter, 0)
+        self.assertDictEqual(myclass._cache, {})
+
+        # Assert that function is called on first access, cache is set
+        self.assertEqual(myclass.foo, "bår")
+        self.assertEqual(myclass.counter, 1)
+        self.assertDictEqual(myclass._cache, {"foo": "bår"})
+
+        # After function is not called on subsequent access, cache is still set
+        self.assertEqual(myclass.foo, "bår")
+        self.assertEqual(myclass.counter, 1)
+        self.assertDictEqual(myclass._cache, {"foo": "bår"})
+
+    def test_cache_custom_key(self):
+        # Init new class with cached properties
+        myclass = self.MyClass()
+        self.assertEqual(myclass.counter, 0)
+        self.assertDictEqual(myclass._cache, {})
+
+        # Assert that function is called on first access, cache is set with custom key
+        self.assertEqual(myclass.bar, "fōo")
+        self.assertEqual(myclass.counter, 1)
+        self.assertDictEqual(myclass._cache, {"hür": "fōo"})
+
+        # After function is not called on subsequent access, cache is still set
+        self.assertEqual(myclass.bar, "fōo")
+        self.assertEqual(myclass.counter, 1)
+        self.assertDictEqual(myclass._cache, {"hür": "fōo"})
diff --git a/gitlint-core/gitlint/tests/test_deprecation.py b/gitlint-core/gitlint/tests/test_deprecation.py
new file mode 100644
index 0000000..bfe5934
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_deprecation.py
@@ -0,0 +1,26 @@
+from gitlint.config import LintConfig
+from gitlint.deprecation import Deprecation
+from gitlint.rules import IgnoreByTitle
+from gitlint.tests.base import (
+    EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING,
+    BaseTestCase,
+)
+
+
+class DeprecationTests(BaseTestCase):
+    def test_get_regex_method(self):
+        config = LintConfig()
+        Deprecation.config = config
+        rule = IgnoreByTitle({"regex": "^Releäse(.*)"})
+
+        # When general.regex-style-search=True, we expect regex.search to be returned and no warning to be logged
+        config.regex_style_search = True
+        regex_method = Deprecation.get_regex_method(rule, rule.options["regex"])
+        self.assertEqual(regex_method, rule.options["regex"].value.search)
+        self.assert_logged([])
+
+        # When general.regex-style-search=False, we expect regex.match to be returned and a warning to be logged
+        config.regex_style_search = False
+        regex_method = Deprecation.get_regex_method(rule, rule.options["regex"])
+        self.assertEqual(regex_method, rule.options["regex"].value.match)
+        self.assert_logged([EXPECTED_REGEX_STYLE_SEARCH_DEPRECATION_WARNING.format("I1", "ignore-by-title")])
diff --git a/gitlint-core/gitlint/tests/test_display.py b/gitlint-core/gitlint/tests/test_display.py
new file mode 100644
index 0000000..e669cdb
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_display.py
@@ -0,0 +1,60 @@
+from io import StringIO
+from unittest.mock import patch
+
+from gitlint.config import LintConfig
+from gitlint.display import Display
+from gitlint.tests.base import BaseTestCase
+
+
+class DisplayTests(BaseTestCase):
+    def test_v(self):
+        display = Display(LintConfig())
+        display.config.verbosity = 2
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            # Non exact outputting, should output both v and vv output
+            with patch("gitlint.display.stdout", new=StringIO()) as stdout:
+                display.v("tëst")
+                display.vv("tëst2")
+                # vvvv should be ignored regardless
+                display.vvv("tëst3.1")
+                display.vvv("tëst3.2", exact=True)
+                self.assertEqual("tëst\ntëst2\n", stdout.getvalue())
+
+            # exact outputting, should only output v
+            with patch("gitlint.display.stdout", new=StringIO()) as stdout:
+                display.v("tëst", exact=True)
+                display.vv("tëst2", exact=True)
+                # vvvv should be ignored regardless
+                display.vvv("tëst3.1")
+                display.vvv("tëst3.2", exact=True)
+                self.assertEqual("tëst2\n", stdout.getvalue())
+
+            # standard error should be empty throughout all of this
+            self.assertEqual("", stderr.getvalue())
+
+    def test_e(self):
+        display = Display(LintConfig())
+        display.config.verbosity = 2
+
+        with patch("gitlint.display.stdout", new=StringIO()) as stdout:
+            # Non exact outputting, should output both v and vv output
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                display.e("tëst")
+                display.ee("tëst2")
+                # vvvv should be ignored regardless
+                display.eee("tëst3.1")
+                display.eee("tëst3.2", exact=True)
+                self.assertEqual("tëst\ntëst2\n", stderr.getvalue())
+
+            # exact outputting, should only output v
+            with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+                display.e("tëst", exact=True)
+                display.ee("tëst2", exact=True)
+                # vvvv should be ignored regardless
+                display.eee("tëst3.1")
+                display.eee("tëst3.2", exact=True)
+                self.assertEqual("tëst2\n", stderr.getvalue())
+
+            # standard output should be empty throughout all of this
+            self.assertEqual("", stdout.getvalue())
diff --git a/gitlint-core/gitlint/tests/test_hooks.py b/gitlint-core/gitlint/tests/test_hooks.py
new file mode 100644
index 0000000..7390f14
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_hooks.py
@@ -0,0 +1,139 @@
+import os
+from unittest.mock import ANY, mock_open, patch
+
+from gitlint.config import LintConfig
+from gitlint.hooks import (
+    COMMIT_MSG_HOOK_DST_PATH,
+    COMMIT_MSG_HOOK_SRC_PATH,
+    GITLINT_HOOK_IDENTIFIER,
+    GitHookInstaller,
+    GitHookInstallerError,
+)
+from gitlint.tests.base import BaseTestCase
+
+
+class HookTests(BaseTestCase):
+    @patch("gitlint.hooks.git_hooks_dir")
+    def test_commit_msg_hook_path(self, git_hooks_dir):
+        git_hooks_dir.return_value = os.path.join("/föo", "bar")
+        lint_config = LintConfig()
+        lint_config.target = self.SAMPLES_DIR
+        expected_path = os.path.join(git_hooks_dir.return_value, COMMIT_MSG_HOOK_DST_PATH)
+        path = GitHookInstaller.commit_msg_hook_path(lint_config)
+
+        git_hooks_dir.assert_called_once_with(self.SAMPLES_DIR)
+        self.assertEqual(path, expected_path)
+
+    @staticmethod
+    @patch("os.chmod")
+    @patch("os.stat")
+    @patch("gitlint.hooks.shutil.copy")
+    @patch("os.path.exists", return_value=False)
+    @patch("os.path.isdir", return_value=True)
+    @patch("gitlint.hooks.git_hooks_dir")
+    def test_install_commit_msg_hook(git_hooks_dir, isdir, path_exists, copy, stat, chmod):
+        lint_config = LintConfig()
+        lint_config.target = os.path.join("/hür", "dur")
+        git_hooks_dir.return_value = os.path.join("/föo", "bar", ".git", "hooks")
+        expected_dst = os.path.join(git_hooks_dir.return_value, COMMIT_MSG_HOOK_DST_PATH)
+        GitHookInstaller.install_commit_msg_hook(lint_config)
+        isdir.assert_called_with(git_hooks_dir.return_value)
+        path_exists.assert_called_once_with(expected_dst)
+        copy.assert_called_once_with(COMMIT_MSG_HOOK_SRC_PATH, expected_dst)
+        stat.assert_called_once_with(expected_dst)
+        chmod.assert_called_once_with(expected_dst, ANY)
+        git_hooks_dir.assert_called_with(lint_config.target)
+
+    @patch("gitlint.hooks.shutil.copy")
+    @patch("os.path.exists", return_value=False)
+    @patch("os.path.isdir", return_value=True)
+    @patch("gitlint.hooks.git_hooks_dir")
+    def test_install_commit_msg_hook_negative(self, git_hooks_dir, isdir, path_exists, copy):
+        lint_config = LintConfig()
+        lint_config.target = os.path.join("/hür", "dur")
+        git_hooks_dir.return_value = os.path.join("/föo", "bar", ".git", "hooks")
+        # mock that current dir is not a git repo
+        isdir.return_value = False
+        expected_msg = f"{lint_config.target} is not a git repository."
+        with self.assertRaisesMessage(GitHookInstallerError, expected_msg):
+            GitHookInstaller.install_commit_msg_hook(lint_config)
+
+        isdir.assert_called_with(git_hooks_dir.return_value)
+        path_exists.assert_not_called()
+        copy.assert_not_called()
+
+        # mock that there is already a commit hook present
+        isdir.return_value = True
+        path_exists.return_value = True
+        expected_dst = os.path.join(git_hooks_dir.return_value, COMMIT_MSG_HOOK_DST_PATH)
+        expected_msg = (
+            f"There is already a commit-msg hook file present in {expected_dst}.\n"
+            "gitlint currently does not support appending to an existing commit-msg file."
+        )
+        with self.assertRaisesMessage(GitHookInstallerError, expected_msg):
+            GitHookInstaller.install_commit_msg_hook(lint_config)
+
+    @staticmethod
+    @patch("os.remove")
+    @patch("os.path.exists", return_value=True)
+    @patch("os.path.isdir", return_value=True)
+    @patch("gitlint.hooks.git_hooks_dir")
+    def test_uninstall_commit_msg_hook(git_hooks_dir, isdir, path_exists, remove):
+        lint_config = LintConfig()
+        git_hooks_dir.return_value = os.path.join("/föo", "bar", ".git", "hooks")
+        lint_config.target = os.path.join("/hür", "dur")
+        read_data = "#!/bin/sh\n" + GITLINT_HOOK_IDENTIFIER
+        with patch("builtins.open", mock_open(read_data=read_data), create=True):
+            GitHookInstaller.uninstall_commit_msg_hook(lint_config)
+
+        expected_dst = os.path.join(git_hooks_dir.return_value, COMMIT_MSG_HOOK_DST_PATH)
+        isdir.assert_called_with(git_hooks_dir.return_value)
+        path_exists.assert_called_once_with(expected_dst)
+        remove.assert_called_with(expected_dst)
+        git_hooks_dir.assert_called_with(lint_config.target)
+
+    @patch("os.remove")
+    @patch("os.path.exists", return_value=True)
+    @patch("os.path.isdir", return_value=True)
+    @patch("gitlint.hooks.git_hooks_dir")
+    def test_uninstall_commit_msg_hook_negative(self, git_hooks_dir, isdir, path_exists, remove):
+        lint_config = LintConfig()
+        lint_config.target = os.path.join("/hür", "dur")
+        git_hooks_dir.return_value = os.path.join("/föo", "bar", ".git", "hooks")
+
+        # mock that the current directory is not a git repo
+        isdir.return_value = False
+        expected_msg = f"{lint_config.target} is not a git repository."
+        with self.assertRaisesMessage(GitHookInstallerError, expected_msg):
+            GitHookInstaller.uninstall_commit_msg_hook(lint_config)
+
+        isdir.assert_called_with(git_hooks_dir.return_value)
+        path_exists.assert_not_called()
+        remove.assert_not_called()
+
+        # mock that there is no commit hook present
+        isdir.return_value = True
+        path_exists.return_value = False
+        expected_dst = os.path.join(git_hooks_dir.return_value, COMMIT_MSG_HOOK_DST_PATH)
+        expected_msg = f"There is no commit-msg hook present in {expected_dst}."
+        with self.assertRaisesMessage(GitHookInstallerError, expected_msg):
+            GitHookInstaller.uninstall_commit_msg_hook(lint_config)
+
+        isdir.assert_called_with(git_hooks_dir.return_value)
+        path_exists.assert_called_once_with(expected_dst)
+        remove.assert_not_called()
+
+        # mock that there is a different (=not gitlint) commit hook
+        isdir.return_value = True
+        path_exists.return_value = True
+        read_data = "#!/bin/sh\nfoo"
+        expected_dst = os.path.join(git_hooks_dir.return_value, COMMIT_MSG_HOOK_DST_PATH)
+        expected_msg = (
+            f"The commit-msg hook in {expected_dst} was not installed by gitlint "
+            "(or it was modified).\nUninstallation of 3th party or modified gitlint hooks "
+            "is not supported."
+        )
+        with patch("builtins.open", mock_open(read_data=read_data), create=True):
+            with self.assertRaisesMessage(GitHookInstallerError, expected_msg):
+                GitHookInstaller.uninstall_commit_msg_hook(lint_config)
+            remove.assert_not_called()
diff --git a/gitlint-core/gitlint/tests/test_lint.py b/gitlint-core/gitlint/tests/test_lint.py
new file mode 100644
index 0000000..1cf3772
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_lint.py
@@ -0,0 +1,296 @@
+from io import StringIO
+from unittest.mock import patch
+
+from gitlint.config import LintConfig, LintConfigBuilder
+from gitlint.lint import GitLinter
+from gitlint.rules import RuleViolation, TitleMustNotContainWord
+from gitlint.tests.base import BaseTestCase
+
+
+class LintTests(BaseTestCase):
+    def test_lint_sample1(self):
+        linter = GitLinter(LintConfig())
+        gitcontext = self.gitcontext(self.get_sample("commit_message/sample1"))
+        violations = linter.lint(gitcontext.commits[-1])
+        # fmt: off
+        expected_errors = [
+            RuleViolation("T3", "Title has trailing punctuation (.)",
+                                "Commit title contåining 'WIP', as well as trailing punctuation.", 1),
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)",
+                            "Commit title contåining 'WIP', as well as trailing punctuation.", 1),
+            RuleViolation("B4", "Second line is not empty", "This line should be empty", 2),
+            RuleViolation("B1", "Line exceeds max length (135>80)",
+                            "This is the first line of the commit message body and it is meant to test " +
+                            "a line that exceeds the maximum line length of 80 characters.", 3),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a tråiling space. ", 4),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a trailing tab.\t", 5),
+            RuleViolation("B3", "Line contains hard tab characters (\\t)",
+                            "This line has a trailing tab.\t", 5)
+        ]
+        # fmt: on
+
+        self.assertListEqual(violations, expected_errors)
+
+    def test_lint_sample2(self):
+        linter = GitLinter(LintConfig())
+        gitcontext = self.gitcontext(self.get_sample("commit_message/sample2"))
+        violations = linter.lint(gitcontext.commits[-1])
+        expected = [
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", "Just a title contåining WIP", 1),
+            RuleViolation("B6", "Body message is missing", None, 3),
+        ]
+
+        self.assertListEqual(violations, expected)
+
+    def test_lint_sample3(self):
+        linter = GitLinter(LintConfig())
+        gitcontext = self.gitcontext(self.get_sample("commit_message/sample3"))
+        violations = linter.lint(gitcontext.commits[-1])
+
+        # fmt: off
+        title = " Commit title containing 'WIP', \tleading and tråiling whitespace and longer than 72 characters."
+        expected = [
+            RuleViolation("T1", "Title exceeds max length (95>72)", title, 1),
+            RuleViolation("T3", "Title has trailing punctuation (.)", title, 1),
+            RuleViolation("T4", "Title contains hard tab characters (\\t)", title, 1),
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", title, 1),
+            RuleViolation("T6", "Title has leading whitespace", title, 1),
+            RuleViolation("B4", "Second line is not empty", "This line should be empty", 2),
+            RuleViolation("B1", "Line exceeds max length (101>80)",
+                            "This is the first line is meånt to test a line that exceeds the maximum line " +
+                            "length of 80 characters.", 3),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a trailing space. ", 4),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a tråiling tab.\t", 5),
+            RuleViolation("B3", "Line contains hard tab characters (\\t)",
+                            "This line has a tråiling tab.\t", 5)
+        ]
+        # fmt: on
+
+        self.assertListEqual(violations, expected)
+
+    def test_lint_sample4(self):
+        commit = self.gitcommit(self.get_sample("commit_message/sample4"))
+        config_builder = LintConfigBuilder()
+        config_builder.set_config_from_commit(commit)
+        linter = GitLinter(config_builder.build())
+        violations = linter.lint(commit)
+        # expect no violations because sample4 has a 'gitlint: disable line'
+        expected = []
+        self.assertListEqual(violations, expected)
+
+    def test_lint_sample5(self):
+        commit = self.gitcommit(self.get_sample("commit_message/sample5"))
+        config_builder = LintConfigBuilder()
+        config_builder.set_config_from_commit(commit)
+        linter = GitLinter(config_builder.build())
+        violations = linter.lint(commit)
+
+        title = " Commit title containing 'WIP', \tleading and tråiling whitespace and longer than 72 characters."
+        # expect only certain violations because sample5 has a 'gitlint-ignore: T3, T6, body-max-line-length'
+        expected = [
+            RuleViolation("T1", "Title exceeds max length (95>72)", title, 1),
+            RuleViolation("T4", "Title contains hard tab characters (\\t)", title, 1),
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", title, 1),
+            RuleViolation("B4", "Second line is not empty", "This line should be ëmpty", 2),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a tråiling space. ", 4),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a trailing tab.\t", 5),
+            RuleViolation("B3", "Line contains hard tab characters (\\t)", "This line has a trailing tab.\t", 5),
+        ]
+        self.assertListEqual(violations, expected)
+
+    def test_lint_meta(self):
+        """Lint sample2 but also add some metadata to the commit so we that gets linted as well"""
+        linter = GitLinter(LintConfig())
+        gitcontext = self.gitcontext(self.get_sample("commit_message/sample2"))
+        gitcontext.commits[0].author_email = "foo bår"
+        violations = linter.lint(gitcontext.commits[-1])
+        expected = [
+            RuleViolation("M1", "Author email for commit is invalid", "foo bår", None),
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", "Just a title contåining WIP", 1),
+            RuleViolation("B6", "Body message is missing", None, 3),
+        ]
+
+        self.assertListEqual(violations, expected)
+
+    def test_lint_ignore(self):
+        lint_config = LintConfig()
+        lint_config.ignore = ["T1", "T3", "T4", "T5", "T6", "B1", "B2"]
+        linter = GitLinter(lint_config)
+        violations = linter.lint(self.gitcommit(self.get_sample("commit_message/sample3")))
+
+        expected = [
+            RuleViolation("B4", "Second line is not empty", "This line should be empty", 2),
+            RuleViolation("B3", "Line contains hard tab characters (\\t)", "This line has a tråiling tab.\t", 5),
+        ]
+
+        self.assertListEqual(violations, expected)
+
+    def test_lint_configuration_rule(self):
+        # Test that all rules are ignored because of matching regex
+        lint_config = LintConfig()
+        lint_config.set_rule_option("I1", "regex", "^Just a title(.*)")
+
+        linter = GitLinter(lint_config)
+        violations = linter.lint(self.gitcommit(self.get_sample("commit_message/sample2")))
+        self.assertListEqual(violations, [])
+
+        # Test ignoring only certain rules
+        lint_config = LintConfig()
+        lint_config.set_rule_option("I1", "regex", "^Just a title(.*)")
+        lint_config.set_rule_option("I1", "ignore", "B6")
+
+        linter = GitLinter(lint_config)
+        violations = linter.lint(self.gitcommit(self.get_sample("commit_message/sample2")))
+
+        # Normally we'd expect a B6 violation, but that one is skipped because of the specific ignore set above
+        expected = [
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", "Just a title contåining WIP", 1)
+        ]
+
+        self.assertListEqual(violations, expected)
+
+        # Test ignoring body lines
+        lint_config = LintConfig()
+        linter = GitLinter(lint_config)
+        lint_config.set_rule_option("I3", "regex", "(.*)tråiling(.*)")
+        violations = linter.lint(self.gitcommit(self.get_sample("commit_message/sample1")))
+        # fmt: off
+        expected_errors = [
+            RuleViolation("T3", "Title has trailing punctuation (.)",
+                                "Commit title contåining 'WIP', as well as trailing punctuation.", 1),
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)",
+                            "Commit title contåining 'WIP', as well as trailing punctuation.", 1),
+            RuleViolation("B4", "Second line is not empty", "This line should be empty", 2),
+            RuleViolation("B1", "Line exceeds max length (135>80)",
+                            "This is the first line of the commit message body and it is meant to test " +
+                            "a line that exceeds the maximum line length of 80 characters.", 3),
+            RuleViolation("B2", "Line has trailing whitespace", "This line has a trailing tab.\t", 4),
+            RuleViolation("B3", "Line contains hard tab characters (\\t)",
+                            "This line has a trailing tab.\t", 4)
+        ]
+        # fmt: on
+        self.assertListEqual(violations, expected_errors)
+
+    def test_lint_special_commit(self):
+        for commit_type in ["merge", "revert", "squash", "fixup", "fixup_amend"]:
+            commit = self.gitcommit(self.get_sample(f"commit_message/{commit_type}"))
+            lintconfig = LintConfig()
+            linter = GitLinter(lintconfig)
+            violations = linter.lint(commit)
+            # Even though there are a number of violations in the commit message, they are ignored because
+            # we are dealing with a merge commit
+            self.assertListEqual(violations, [])
+
+            # Check that we do see violations if we disable 'ignore-merge-commits'
+            setattr(lintconfig, f"ignore_{commit_type}_commits", False)
+            linter = GitLinter(lintconfig)
+            violations = linter.lint(commit)
+            self.assertTrue(len(violations) > 0)
+
+    def test_lint_regex_rules(self):
+        """Additional test for title-match-regex, body-match-regex"""
+        commit = self.gitcommit(self.get_sample("commit_message/no-violations"))
+        lintconfig = LintConfig()
+        linter = GitLinter(lintconfig)
+        violations = linter.lint(commit)
+        # No violations by default
+        self.assertListEqual(violations, [])
+
+        # Matching regexes shouldn't be a problem
+        rule_regexes = [("title-match-regex", "Tïtle$"), ("body-match-regex", "Sïgned-Off-By: (.*)$")]
+        for rule_regex in rule_regexes:
+            lintconfig.set_rule_option(rule_regex[0], "regex", rule_regex[1])
+            violations = linter.lint(commit)
+            self.assertListEqual(violations, [])
+
+        # Non-matching regexes should return violations
+        rule_regexes = [("title-match-regex",), ("body-match-regex",)]
+        lintconfig.set_rule_option("title-match-regex", "regex", "^Tïtle")
+        lintconfig.set_rule_option("body-match-regex", "regex", "Sügned-Off-By: (.*)$")
+        expected_violations = [
+            RuleViolation("T7", "Title does not match regex (^Tïtle)", "Normal Commit Tïtle", 1),
+            RuleViolation("B8", "Body does not match regex (Sügned-Off-By: (.*)$)", None, 6),
+        ]
+        violations = linter.lint(commit)
+        self.assertListEqual(violations, expected_violations)
+
+    def test_print_violations(self):
+        violations = [
+            RuleViolation("RULE_ID_1", "Error Messåge 1", "Violating Content 1", None),
+            RuleViolation("RULE_ID_2", "Error Message 2", "Violåting Content 2", 2),
+        ]
+        linter = GitLinter(LintConfig())
+
+        # test output with increasing verbosity
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            linter.config.verbosity = 0
+            linter.print_violations(violations)
+            self.assertEqual("", stderr.getvalue())
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            linter.config.verbosity = 1
+            linter.print_violations(violations)
+            expected = "-: RULE_ID_1\n2: RULE_ID_2\n"
+            self.assertEqual(expected, stderr.getvalue())
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            linter.config.verbosity = 2
+            linter.print_violations(violations)
+            expected = "-: RULE_ID_1 Error Messåge 1\n2: RULE_ID_2 Error Message 2\n"
+            self.assertEqual(expected, stderr.getvalue())
+
+        with patch("gitlint.display.stderr", new=StringIO()) as stderr:
+            linter.config.verbosity = 3
+            linter.print_violations(violations)
+            expected = (
+                '-: RULE_ID_1 Error Messåge 1: "Violating Content 1"\n'
+                + '2: RULE_ID_2 Error Message 2: "Violåting Content 2"\n'
+            )
+            self.assertEqual(expected, stderr.getvalue())
+
+    def test_named_rules(self):
+        """Test that when named rules are present, both them and the original (non-named) rules executed"""
+
+        lint_config = LintConfig()
+        for rule_name in ["my-ïd", "another-rule-ïd"]:
+            rule_id = TitleMustNotContainWord.id + ":" + rule_name
+            lint_config.rules.add_rule(TitleMustNotContainWord, rule_id)
+            lint_config.set_rule_option(rule_id, "words", ["Föo"])
+            linter = GitLinter(lint_config)
+
+        violations = [
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", "WIP: Föo bar", 1),
+            RuleViolation("T5:another-rule-ïd", "Title contains the word 'Föo' (case-insensitive)", "WIP: Föo bar", 1),
+            RuleViolation("T5:my-ïd", "Title contains the word 'Föo' (case-insensitive)", "WIP: Föo bar", 1),
+        ]
+        self.assertListEqual(violations, linter.lint(self.gitcommit("WIP: Föo bar\n\nFoo bår hur dur bla bla")))
+
+    def test_ignore_named_rules(self):
+        """Test that named rules can be ignored"""
+
+        # Add named rule to lint config
+        config_builder = LintConfigBuilder()
+        rule_id = TitleMustNotContainWord.id + ":my-ïd"
+        config_builder.set_option(rule_id, "words", ["Föo"])
+        lint_config = config_builder.build()
+        linter = GitLinter(lint_config)
+        commit = self.gitcommit("WIP: Föo bar\n\nFoo bår hur dur bla bla")
+
+        # By default, we expect both the violations of the regular rule as well as the named rule to show up
+        violations = [
+            RuleViolation("T5", "Title contains the word 'WIP' (case-insensitive)", "WIP: Föo bar", 1),
+            RuleViolation("T5:my-ïd", "Title contains the word 'Föo' (case-insensitive)", "WIP: Föo bar", 1),
+        ]
+        self.assertListEqual(violations, linter.lint(commit))
+
+        # ignore regular rule: only named rule violations show up
+        lint_config.ignore = ["T5"]
+        self.assertListEqual(violations[1:], linter.lint(commit))
+
+        # ignore named rule by id: only regular rule violations show up
+        lint_config.ignore = [rule_id]
+        self.assertListEqual(violations[:-1], linter.lint(commit))
+
+        # ignore named rule by name: only regular rule violations show up
+        lint_config.ignore = [TitleMustNotContainWord.name + ":my-ïd"]
+        self.assertListEqual(violations[:-1], linter.lint(commit))
diff --git a/gitlint-core/gitlint/tests/test_options.py b/gitlint-core/gitlint/tests/test_options.py
new file mode 100644
index 0000000..deff723
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_options.py
@@ -0,0 +1,240 @@
+import os
+import re
+
+from gitlint.options import (
+    BoolOption,
+    IntOption,
+    ListOption,
+    PathOption,
+    RegexOption,
+    RuleOptionError,
+    StrOption,
+)
+from gitlint.tests.base import BaseTestCase
+
+
+class RuleOptionTests(BaseTestCase):
+    def test_option__str__(self):
+        option = StrOption("tëst-option", "åbc", "Test Dëscription")
+        self.assertEqual(str(option), "(tëst-option: åbc (Test Dëscription))")
+
+    def test_option_equality(self):
+        options = {
+            IntOption: 123,
+            StrOption: "foöbar",
+            BoolOption: False,
+            ListOption: ["a", "b"],
+            PathOption: ".",
+            RegexOption: "^foöbar(.*)",
+        }
+        for clazz, val in options.items():
+            # 2 options are equal if their name, value and description match
+            option1 = clazz("test-öption", val, "Test Dëscription")
+            option2 = clazz("test-öption", val, "Test Dëscription")
+            self.assertEqual(option1, option2)
+
+        # Not equal: class, name, description, value are different
+        self.assertNotEqual(option1, IntOption("tëst-option1", 123, "Test Dëscription"))
+        self.assertNotEqual(option1, StrOption("tëst-option1", "åbc", "Test Dëscription"))
+        self.assertNotEqual(option1, StrOption("tëst-option", "åbcd", "Test Dëscription"))
+        self.assertNotEqual(option1, StrOption("tëst-option", "åbc", "Test Dëscription2"))
+
+    def test_int_option(self):
+        # normal behavior
+        option = IntOption("tëst-name", 123, "Tëst Description")
+        self.assertEqual(option.name, "tëst-name")
+        self.assertEqual(option.description, "Tëst Description")
+        self.assertEqual(option.value, 123)
+
+        # re-set value
+        option.set(456)
+        self.assertEqual(option.value, 456)
+
+        # set to None
+        option.set(None)
+        self.assertEqual(option.value, None)
+
+        # error on negative int when not allowed
+        expected_error = "Option 'tëst-name' must be a positive integer (current value: '-123')"
+        with self.assertRaisesMessage(RuleOptionError, expected_error):
+            option.set(-123)
+
+        # error on non-int value
+        expected_error = "Option 'tëst-name' must be a positive integer (current value: 'foo')"
+        with self.assertRaisesMessage(RuleOptionError, expected_error):
+            option.set("foo")
+
+        # no error on negative value when allowed and negative int is passed
+        option = IntOption("test-name", 123, "Test Description", allow_negative=True)
+        option.set(-456)
+        self.assertEqual(option.value, -456)
+
+        # error on non-int value when negative int is allowed
+        expected_error = "Option 'test-name' must be an integer (current value: 'foo')"
+        with self.assertRaisesMessage(RuleOptionError, expected_error):
+            option.set("foo")
+
+    def test_str_option(self):
+        # normal behavior
+        option = StrOption("tëst-name", "föo", "Tëst Description")
+        self.assertEqual(option.name, "tëst-name")
+        self.assertEqual(option.description, "Tëst Description")
+        self.assertEqual(option.value, "föo")
+
+        # re-set value
+        option.set("bår")
+        self.assertEqual(option.value, "bår")
+
+        # conversion to str
+        option.set(123)
+        self.assertEqual(option.value, "123")
+
+        # conversion to str
+        option.set(-123)
+        self.assertEqual(option.value, "-123")
+
+        # None value
+        option.set(None)
+        self.assertEqual(option.value, None)
+
+    def test_boolean_option(self):
+        # normal behavior
+        option = BoolOption("tëst-name", "true", "Tëst Description")
+        self.assertEqual(option.name, "tëst-name")
+        self.assertEqual(option.description, "Tëst Description")
+        self.assertEqual(option.value, True)
+
+        # re-set value
+        option.set("False")
+        self.assertEqual(option.value, False)
+
+        # Re-set using actual boolean
+        option.set(True)
+        self.assertEqual(option.value, True)
+
+        # error on incorrect value
+        incorrect_values = [1, -1, "foo", "bår", ["foo"], {"foo": "bar"}, None]
+        for value in incorrect_values:
+            with self.assertRaisesMessage(RuleOptionError, "Option 'tëst-name' must be either 'true' or 'false'"):
+                option.set(value)
+
+    def test_list_option(self):
+        # normal behavior
+        option = ListOption("tëst-name", "å,b,c,d", "Tëst Description")
+        self.assertEqual(option.name, "tëst-name")
+        self.assertEqual(option.description, "Tëst Description")
+        self.assertListEqual(option.value, ["å", "b", "c", "d"])
+
+        # re-set value
+        option.set("1,2,3,4")
+        self.assertListEqual(option.value, ["1", "2", "3", "4"])
+
+        # set list
+        option.set(["foo", "bår", "test"])
+        self.assertListEqual(option.value, ["foo", "bår", "test"])
+
+        # None
+        option.set(None)
+        self.assertIsNone(option.value)
+
+        # empty string
+        option.set("")
+        self.assertListEqual(option.value, [])
+
+        # whitespace string
+        option.set("  \t  ")
+        self.assertListEqual(option.value, [])
+
+        # empty list
+        option.set([])
+        self.assertListEqual(option.value, [])
+
+        # trailing comma
+        option.set("ë,f,g,")
+        self.assertListEqual(option.value, ["ë", "f", "g"])
+
+        # leading and trailing whitespace should be trimmed, but only deduped within text
+        option.set(" abc , def   , ghi \t  , jkl  mno  ")
+        self.assertListEqual(option.value, ["abc", "def", "ghi", "jkl  mno"])
+
+        # Also strip whitespace within a list
+        option.set(["\t foo", "bar \t ", " test  123 "])
+        self.assertListEqual(option.value, ["foo", "bar", "test  123"])
+
+        # conversion to string before split
+        option.set(123)
+        self.assertListEqual(option.value, ["123"])
+
+    def test_path_option(self):
+        option = PathOption("tëst-directory", ".", "Tëst Description", type="dir")
+        self.assertEqual(option.name, "tëst-directory")
+        self.assertEqual(option.description, "Tëst Description")
+        self.assertEqual(option.value, os.path.realpath("."))
+        self.assertEqual(option.type, "dir")
+
+        # re-set value
+        option.set(self.SAMPLES_DIR)
+        self.assertEqual(option.value, self.SAMPLES_DIR)
+
+        # set to None
+        option.set(None)
+        self.assertIsNone(option.value)
+
+        # set to int
+        expected = "Option tëst-directory must be an existing directory (current value: '1234')"
+        with self.assertRaisesMessage(RuleOptionError, expected):
+            option.set(1234)
+
+        # set to non-existing directory
+        non_existing_path = os.path.join("/föo", "bar")
+        expected = f"Option tëst-directory must be an existing directory (current value: '{non_existing_path}')"
+        with self.assertRaisesMessage(RuleOptionError, expected):
+            option.set(non_existing_path)
+
+        # set to a file, should raise exception since option.type = dir
+        sample_path = self.get_sample_path(os.path.join("commit_message", "sample1"))
+        expected = f"Option tëst-directory must be an existing directory (current value: '{sample_path}')"
+        with self.assertRaisesMessage(RuleOptionError, expected):
+            option.set(sample_path)
+
+        # set option.type = file, file should now be accepted, directories not
+        option.type = "file"
+        option.set(sample_path)
+        self.assertEqual(option.value, sample_path)
+        expected = f"Option tëst-directory must be an existing file (current value: '{self.get_sample_path()}')"
+        with self.assertRaisesMessage(RuleOptionError, expected):
+            option.set(self.get_sample_path())
+
+        # set option.type = both, files and directories should now be accepted
+        option.type = "both"
+        option.set(sample_path)
+        self.assertEqual(option.value, sample_path)
+        option.set(self.get_sample_path())
+        self.assertEqual(option.value, self.get_sample_path())
+
+        # Expect exception if path type is invalid
+        option.type = "föo"
+        expected = "Option tëst-directory type must be one of: 'file', 'dir', 'both' (current: 'föo')"
+        with self.assertRaisesMessage(RuleOptionError, expected):
+            option.set("haha")
+
+    def test_regex_option(self):
+        # normal behavior
+        option = RegexOption("tëst-regex", "^myrëgex(.*)foo$", "Tëst Regex Description")
+        self.assertEqual(option.name, "tëst-regex")
+        self.assertEqual(option.description, "Tëst Regex Description")
+        self.assertEqual(option.value, re.compile("^myrëgex(.*)foo$", re.UNICODE))
+
+        # re-set value
+        option.set("[0-9]föbar.*")
+        self.assertEqual(option.value, re.compile("[0-9]föbar.*", re.UNICODE))
+
+        # set None
+        option.set(None)
+        self.assertIsNone(option.value)
+
+        # error on invalid regex
+        incorrect_values = ["foo(", 123, -1]
+        for value in incorrect_values:
+            with self.assertRaisesRegex(RuleOptionError, "Invalid regular expression"):
+                option.set(value)
diff --git a/gitlint-core/gitlint/tests/test_utils.py b/gitlint-core/gitlint/tests/test_utils.py
new file mode 100644
index 0000000..d21ec3f
--- /dev/null
+++ b/gitlint-core/gitlint/tests/test_utils.py
@@ -0,0 +1,70 @@
+from unittest.mock import patch
+
+from gitlint import utils
+from gitlint.tests.base import BaseTestCase
+
+
+class UtilsTests(BaseTestCase):
+    def tearDown(self):
+        # Since we're messing around with `utils.PLATFORM_IS_WINDOWS` during these tests, we need to reset
+        # its value after we're done this doesn't influence other tests
+        utils.PLATFORM_IS_WINDOWS = utils.platform_is_windows()
+
+    @patch("os.environ")
+    def test_use_sh_library(self, patched_env):
+        patched_env.get.return_value = "1"
+        self.assertEqual(utils.use_sh_library(), True)
+        patched_env.get.assert_called_once_with("GITLINT_USE_SH_LIB", None)
+
+        for invalid_val in ["0", "foöbar"]:
+            patched_env.get.reset_mock()  # reset mock call count
+            patched_env.get.return_value = invalid_val
+            self.assertEqual(utils.use_sh_library(), False, invalid_val)
+            patched_env.get.assert_called_once_with("GITLINT_USE_SH_LIB", None)
+
+        # Assert that when GITLINT_USE_SH_LIB is not set, we fallback to False (not using)
+        patched_env.get.return_value = None
+        self.assertEqual(utils.use_sh_library(), False)
+
+    @patch("gitlint.utils.locale")
+    def test_terminal_encoding_non_windows(self, mocked_locale):
+        utils.PLATFORM_IS_WINDOWS = False
+        mocked_locale.getpreferredencoding.return_value = "foöbar"
+        self.assertEqual(utils.getpreferredencoding(), "foöbar")
+        mocked_locale.getpreferredencoding.assert_called_once()
+
+        mocked_locale.getpreferredencoding.return_value = False
+        self.assertEqual(utils.getpreferredencoding(), "UTF-8")
+
+    @patch("os.environ")
+    def test_terminal_encoding_windows(self, patched_env):
+        utils.PLATFORM_IS_WINDOWS = True
+        # Mock out os.environ
+        mock_env = {}
+
+        def mocked_get(key, default):
+            return mock_env.get(key, default)
+
+        patched_env.get.side_effect = mocked_get
+
+        # Assert getpreferredencoding reads env vars in order: LC_ALL, LC_CTYPE, LANG
+        mock_env = {"LC_ALL": "ASCII", "LC_CTYPE": "UTF-16", "LANG": "CP1251"}
+        self.assertEqual(utils.getpreferredencoding(), "ASCII")
+        mock_env = {"LC_CTYPE": "UTF-16", "LANG": "CP1251"}
+        self.assertEqual(utils.getpreferredencoding(), "UTF-16")
+        mock_env = {"LANG": "CP1251"}
+        self.assertEqual(utils.getpreferredencoding(), "CP1251")
+
+        # Assert split on dot
+        mock_env = {"LANG": "foo.UTF-16"}
+        self.assertEqual(utils.getpreferredencoding(), "UTF-16")
+
+        # assert default encoding is UTF-8
+        mock_env = {}
+        self.assertEqual(utils.getpreferredencoding(), "UTF-8")
+        mock_env = {"FOO": "föo"}
+        self.assertEqual(utils.getpreferredencoding(), "UTF-8")
+
+        # assert fallback encoding is UTF-8 in case we set an unavailable encoding
+        mock_env = {"LC_ALL": "foo"}
+        self.assertEqual(utils.getpreferredencoding(), "UTF-8")
diff --git a/gitlint-core/gitlint/utils.py b/gitlint-core/gitlint/utils.py
new file mode 100644
index 0000000..3ccb78b
--- /dev/null
+++ b/gitlint-core/gitlint/utils.py
@@ -0,0 +1,87 @@
+import codecs
+import locale
+import os
+import platform
+
+# Note: While we can easily inline the logic related to the constants set in this module, we deliberately create
+# small functions that encapsulate that logic as this enables easy unit testing. In particular, by creating functions
+# we can easily mock the dependencies during testing, which is not possible if the code is not enclosed in a function
+# and just executed at import-time.
+
+########################################################################################################################
+LOG_FORMAT = "%(levelname)s: %(name)s %(message)s"
+
+########################################################################################################################
+# PLATFORM_IS_WINDOWS
+
+
+def platform_is_windows():
+    return "windows" in platform.system().lower()
+
+
+PLATFORM_IS_WINDOWS = platform_is_windows()
+
+########################################################################################################################
+# USE_SH_LIB
+# Determine whether to use the `sh` library
+# On windows we won't want to use the sh library since it's not supported - instead we'll use our own shell module.
+# However, we want to be able to overwrite this behavior for testing using the GITLINT_USE_SH_LIB env var.
+
+
+def use_sh_library():
+    gitlint_use_sh_lib_env = os.environ.get("GITLINT_USE_SH_LIB", None)
+    if gitlint_use_sh_lib_env:
+        return gitlint_use_sh_lib_env == "1"
+    return False
+
+
+USE_SH_LIB = use_sh_library()
+
+########################################################################################################################
+# TERMINAL_ENCODING
+# Encoding used for terminal encoding/decoding.
+
+
+def getpreferredencoding():
+    """Modified version of local.getpreferredencoding() that takes into account LC_ALL, LC_CTYPE, LANG env vars
+    on windows and falls back to UTF-8."""
+    fallback_encoding = "UTF-8"
+    preferred_encoding = locale.getpreferredencoding() or fallback_encoding
+
+    # On Windows, we mimic git/linux by trying to read the LC_ALL, LC_CTYPE, LANG env vars manually
+    # (on Linux/MacOS the `getpreferredencoding()` call will take care of this).
+    # We fallback to UTF-8
+    if PLATFORM_IS_WINDOWS:
+        preferred_encoding = fallback_encoding
+        for env_var in ["LC_ALL", "LC_CTYPE", "LANG"]:
+            encoding = os.environ.get(env_var, False)
+            if encoding:
+                # Support dotted (C.UTF-8) and non-dotted (C or UTF-8) charsets:
+                # If encoding contains a dot: split and use second part, otherwise use everything
+                dot_index = encoding.find(".")
+                preferred_encoding = encoding[dot_index + 1 :] if dot_index != -1 else encoding
+                break
+
+        # We've determined what encoding the user *wants*, let's now check if it's actually a valid encoding on the
+        # system. If not, fallback to UTF-8.
+        # This scenario is fairly common on Windows where git sets LC_CTYPE=C when invoking the commit-msg hook, which
+        # is not a valid encoding in Python on Windows.
+        try:
+            codecs.lookup(preferred_encoding)
+        except LookupError:
+            preferred_encoding = fallback_encoding
+
+    return preferred_encoding
+
+
+TERMINAL_ENCODING = getpreferredencoding()
+
+########################################################################################################################
+# FILE_ENCODING
+# Gitlint assumes UTF-8 encoding for all file operations:
+#  - reading/writing its own hook and config files
+#  - reading/writing git commit messages
+# Git does have i18n.commitEncoding and i18n.logOutputEncoding options which we might want to take into account,
+# but that's not supported today.
+
+FILE_ENCODING = "UTF-8"
diff --git a/gitlint-core/pyproject.toml b/gitlint-core/pyproject.toml
new file mode 100644
index 0000000..e65b7b0
--- /dev/null
+++ b/gitlint-core/pyproject.toml
@@ -0,0 +1,71 @@
+[build-system]
+requires = ["hatchling", "hatch-vcs"]
+build-backend = "hatchling.build"
+
+[project]
+name = "gitlint-core"
+dynamic = ["version", "urls"]
+description = "Git commit message linter written in python, checks your commit messages for style."
+readme = "README.md"
+license = "MIT"
+requires-python = ">=3.7"
+authors = [{ name = "Joris Roovers" }]
+keywords = [
+    "git",
+    "gitlint",
+    "lint",    # 
+]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Environment :: Console",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
+    "Topic :: Software Development :: Quality Assurance",
+    "Topic :: Software Development :: Testing",
+]
+dependencies = [
+    "arrow>=1",
+    "Click>=8",
+    "importlib-metadata >= 1.0 ; python_version < \"3.8\"",
+    "sh>=1.13.0 ; sys_platform != \"win32\"",
+]
+
+[project.optional-dependencies]
+trusted-deps = [
+    "arrow==1.2.3",
+    "Click==8.1.3",
+    "sh==1.14.3 ; sys_platform != \"win32\"",
+]
+
+[project.scripts]
+gitlint = "gitlint.cli:cli"
+
+[tool.hatch.version]
+source = "vcs"
+raw-options = { root = ".." }
+
+[tool.hatch.build]
+include = [
+    "/gitlint", #
+]
+
+exclude = [
+    "/gitlint/tests", #
+]
+
+[tool.hatch.metadata.hooks.vcs.urls]
+Homepage = "https://jorisroovers.github.io/gitlint"
+Documentation = "https://jorisroovers.github.io/gitlint"
+Source = "https://github.com/jorisroovers/gitlint/tree/main/gitlint-core"
+Changelog = "https://github.com/jorisroovers/gitlint/blob/main/CHANGELOG.md"
+# TODO(jorisroovers): Temporary disable until fixed in hatch-vcs (see #460)
+# 'Source Commit' = "https://github.com/jorisroovers/gitlint/tree/{commit_hash}/gitlint-core"
\ No newline at end of file
-- 
cgit v1.2.3