1 files changed, 121 insertions, 0 deletions
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")