Merging upstream version 2.8.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

14 files changed, 318 insertions, 81 deletions

diff --git a/tests/commands/install_uninstall_test.py b/tests/commands/install_uninstall_test.py
index 5809a3f..7a4b906 100644
--- a/tests/commands/install_uninstall_test.py
+++ b/tests/commands/install_uninstall_test.py
@@ -3,6 +3,8 @@ import re
 import sys
 from unittest import mock
 
+import re_assert
+
 import pre_commit.constants as C
 from pre_commit import git
 from pre_commit.commands import install_uninstall
@@ -54,8 +56,13 @@ def patch_sys_exe(exe):
 
 
 def test_shebang_windows():
+    with patch_platform('win32'), patch_sys_exe('python'):
+        assert shebang() == '#!/usr/bin/env python'
+
+
+def test_shebang_windows_drop_ext():
     with patch_platform('win32'), patch_sys_exe('python.exe'):
-        assert shebang() == '#!/usr/bin/env python.exe'
+        assert shebang() == '#!/usr/bin/env python'
 
 
 def test_shebang_posix_not_on_path():
@@ -143,7 +150,7 @@ FILES_CHANGED = (
 )
 
 
-NORMAL_PRE_COMMIT_RUN = re.compile(
+NORMAL_PRE_COMMIT_RUN = re_assert.Matches(
     fr'^\[INFO\] Initializing environment for .+\.\n'
     fr'Bash hook\.+Passed\n'
     fr'\[master [a-f0-9]{{7}}\] commit!\n'
@@ -159,7 +166,7 @@ def test_install_pre_commit_and_run(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_install_pre_commit_and_run_custom_path(tempdir_factory, store):
@@ -171,7 +178,7 @@ def test_install_pre_commit_and_run_custom_path(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_install_in_submodule_and_run(tempdir_factory, store):
@@ -185,7 +192,7 @@ def test_install_in_submodule_and_run(tempdir_factory, store):
         assert install(C.CONFIG_FILE, store, hook_types=['pre-commit']) == 0
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_install_in_worktree_and_run(tempdir_factory, store):
@@ -198,7 +205,7 @@ def test_install_in_worktree_and_run(tempdir_factory, store):
         assert install(C.CONFIG_FILE, store, hook_types=['pre-commit']) == 0
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_commit_am(tempdir_factory, store):
@@ -243,7 +250,7 @@ def test_install_idempotent(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def _path_without_us():
@@ -297,7 +304,7 @@ def test_environment_not_sourced(tempdir_factory, store):
         )
 
 
-FAILING_PRE_COMMIT_RUN = re.compile(
+FAILING_PRE_COMMIT_RUN = re_assert.Matches(
     r'^\[INFO\] Initializing environment for .+\.\n'
     r'Failing hook\.+Failed\n'
     r'- hook id: failing_hook\n'
@@ -316,10 +323,10 @@ def test_failing_hooks_returns_nonzero(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 1
-        assert FAILING_PRE_COMMIT_RUN.match(output)
+        FAILING_PRE_COMMIT_RUN.assert_matches(output)
 
 
-EXISTING_COMMIT_RUN = re.compile(
+EXISTING_COMMIT_RUN = re_assert.Matches(
     fr'^legacy hook\n'
     fr'\[master [a-f0-9]{{7}}\] commit!\n'
     fr'{FILES_CHANGED}'
@@ -342,7 +349,7 @@ def test_install_existing_hooks_no_overwrite(tempdir_factory, store):
         # Make sure we installed the "old" hook correctly
         ret, output = _get_commit_output(tempdir_factory, touch_file='baz')
         assert ret == 0
-        assert EXISTING_COMMIT_RUN.match(output)
+        EXISTING_COMMIT_RUN.assert_matches(output)
 
         # Now install pre-commit (no-overwrite)
         assert install(C.CONFIG_FILE, store, hook_types=['pre-commit']) == 0
@@ -351,7 +358,7 @@ def test_install_existing_hooks_no_overwrite(tempdir_factory, store):
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
         assert output.startswith('legacy hook\n')
-        assert NORMAL_PRE_COMMIT_RUN.match(output[len('legacy hook\n'):])
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output[len('legacy hook\n'):])
 
 
 def test_legacy_overwriting_legacy_hook(tempdir_factory, store):
@@ -377,10 +384,10 @@ def test_install_existing_hook_no_overwrite_idempotent(tempdir_factory, store):
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
         assert output.startswith('legacy hook\n')
-        assert NORMAL_PRE_COMMIT_RUN.match(output[len('legacy hook\n'):])
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output[len('legacy hook\n'):])
 
 
-FAIL_OLD_HOOK = re.compile(
+FAIL_OLD_HOOK = re_assert.Matches(
     r'fail!\n'
     r'\[INFO\] Initializing environment for .+\.\n'
     r'Bash hook\.+Passed\n',
@@ -401,7 +408,7 @@ def test_failing_existing_hook_returns_1(tempdir_factory, store):
         # We should get a failure from the legacy hook
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 1
-        assert FAIL_OLD_HOOK.match(output)
+        FAIL_OLD_HOOK.assert_matches(output)
 
 
 def test_install_overwrite_no_existing_hooks(tempdir_factory, store):
@@ -413,7 +420,7 @@ def test_install_overwrite_no_existing_hooks(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_install_overwrite(tempdir_factory, store):
@@ -426,7 +433,7 @@ def test_install_overwrite(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_uninstall_restores_legacy_hooks(tempdir_factory, store):
@@ -441,7 +448,7 @@ def test_uninstall_restores_legacy_hooks(tempdir_factory, store):
         # Make sure we installed the "old" hook correctly
         ret, output = _get_commit_output(tempdir_factory, touch_file='baz')
         assert ret == 0
-        assert EXISTING_COMMIT_RUN.match(output)
+        EXISTING_COMMIT_RUN.assert_matches(output)
 
 
 def test_replace_old_commit_script(tempdir_factory, store):
@@ -463,7 +470,7 @@ def test_replace_old_commit_script(tempdir_factory, store):
 
         ret, output = _get_commit_output(tempdir_factory)
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def test_uninstall_doesnt_remove_not_our_hooks(in_git_dir):
@@ -476,7 +483,7 @@ def test_uninstall_doesnt_remove_not_our_hooks(in_git_dir):
     assert pre_commit.exists()
 
 
-PRE_INSTALLED = re.compile(
+PRE_INSTALLED = re_assert.Matches(
     fr'Bash hook\.+Passed\n'
     fr'\[master [a-f0-9]{{7}}\] commit!\n'
     fr'{FILES_CHANGED}'
@@ -493,7 +500,7 @@ def test_installs_hooks_with_hooks_True(tempdir_factory, store):
         )
 
         assert ret == 0
-        assert PRE_INSTALLED.match(output)
+        PRE_INSTALLED.assert_matches(output)
 
 
 def test_install_hooks_command(tempdir_factory, store):
@@ -506,7 +513,7 @@ def test_install_hooks_command(tempdir_factory, store):
         )
 
         assert ret == 0
-        assert PRE_INSTALLED.match(output)
+        PRE_INSTALLED.assert_matches(output)
 
 
 def test_installed_from_venv(tempdir_factory, store):
@@ -533,7 +540,7 @@ def test_installed_from_venv(tempdir_factory, store):
             },
         )
         assert ret == 0
-        assert NORMAL_PRE_COMMIT_RUN.match(output)
+        NORMAL_PRE_COMMIT_RUN.assert_matches(output)
 
 
 def _get_push_output(tempdir_factory, remote='origin', opts=()):
@@ -880,7 +887,7 @@ def test_prepare_commit_msg_legacy(
 
 
 def test_pre_merge_commit_integration(tempdir_factory, store):
-    expected = re.compile(
+    output_pattern = re_assert.Matches(
         r'^\[INFO\] Initializing environment for .+\n'
         r'Bash hook\.+Passed\n'
         r"Merge made by the 'recursive' strategy.\n"
@@ -902,7 +909,7 @@ def test_pre_merge_commit_integration(tempdir_factory, store):
             tempdir_factory=tempdir_factory,
         )
         assert ret == 0
-        assert expected.match(output)
+        output_pattern.assert_matches(output)
 
 
 def test_install_disallow_missing_config(tempdir_factory, store):
diff --git a/tests/commands/run_test.py b/tests/commands/run_test.py
index 2461ed5..00b4712 100644
--- a/tests/commands/run_test.py
+++ b/tests/commands/run_test.py
@@ -2,6 +2,7 @@ import os.path
 import shlex
 import sys
 import time
+from typing import MutableMapping
 from unittest import mock
 
 import pytest
@@ -18,7 +19,6 @@ from pre_commit.commands.run import Classifier
 from pre_commit.commands.run import filter_by_include_exclude
 from pre_commit.commands.run import run
 from pre_commit.util import cmd_output
-from pre_commit.util import EnvironT
 from pre_commit.util import make_executable
 from testing.auto_namedtuple import auto_namedtuple
 from testing.fixtures import add_config_to_repo
@@ -482,7 +482,7 @@ def test_all_push_options_ok(cap_out, store, repo_with_passing_hook):
 
 def test_checkout_type(cap_out, store, repo_with_passing_hook):
     args = run_opts(from_ref='', to_ref='', checkout_type='1')
-    environ: EnvironT = {}
+    environ: MutableMapping[str, str] = {}
     ret, printed = _do_run(
         cap_out, store, repo_with_passing_hook, args, environ,
     )
@@ -1032,7 +1032,7 @@ def test_skipped_without_any_setup_for_post_checkout(in_git_dir, store):
 
 def test_pre_commit_env_variable_set(cap_out, store, repo_with_passing_hook):
     args = run_opts()
-    environ: EnvironT = {}
+    environ: MutableMapping[str, str] = {}
     ret, printed = _do_run(
         cap_out, store, repo_with_passing_hook, args, environ,
     )
diff --git a/tests/commands/sample_config_test.py b/tests/commands/sample_config_test.py
index 11c0876..8e3a904 100644
--- a/tests/commands/sample_config_test.py
+++ b/tests/commands/sample_config_test.py
@@ -10,7 +10,7 @@ def test_sample_config(capsys):
 # See https://pre-commit.com/hooks.html for more hooks
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v2.4.0
+    rev: v3.2.0
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
diff --git a/tests/commands/try_repo_test.py b/tests/commands/try_repo_test.py
index d3ec3fd..a157d16 100644
--- a/tests/commands/try_repo_test.py
+++ b/tests/commands/try_repo_test.py
@@ -3,6 +3,8 @@ import re
 import time
 from unittest import mock
 
+import re_assert
+
 from pre_commit import git
 from pre_commit.commands.try_repo import try_repo
 from pre_commit.util import cmd_output
@@ -43,7 +45,7 @@ def test_try_repo_repo_only(cap_out, tempdir_factory):
         _run_try_repo(tempdir_factory, verbose=True)
     start, config, rest = _get_out(cap_out)
     assert start == ''
-    assert re.match(
+    config_pattern = re_assert.Matches(
         '^repos:\n'
         '-   repo: .+\n'
         '    rev: .+\n'
@@ -51,8 +53,8 @@ def test_try_repo_repo_only(cap_out, tempdir_factory):
         '    -   id: bash_hook\n'
         '    -   id: bash_hook2\n'
         '    -   id: bash_hook3\n$',
-        config,
     )
+    config_pattern.assert_matches(config)
     assert rest == '''\
 Bash hook............................................(no files to check)Skipped
 - hook id: bash_hook
@@ -71,14 +73,14 @@ def test_try_repo_with_specific_hook(cap_out, tempdir_factory):
     _run_try_repo(tempdir_factory, hook='bash_hook', verbose=True)
     start, config, rest = _get_out(cap_out)
     assert start == ''
-    assert re.match(
+    config_pattern = re_assert.Matches(
         '^repos:\n'
         '-   repo: .+\n'
         '    rev: .+\n'
         '    hooks:\n'
         '    -   id: bash_hook\n$',
-        config,
     )
+    config_pattern.assert_matches(config)
     assert rest == '''\
 Bash hook............................................(no files to check)Skipped
 - hook id: bash_hook
@@ -128,14 +130,14 @@ def test_try_repo_uncommitted_changes(cap_out, tempdir_factory):
 
     start, config, rest = _get_out(cap_out)
     assert start == '[WARNING] Creating temporary repo with uncommitted changes...\n'  # noqa: E501
-    assert re.match(
+    config_pattern = re_assert.Matches(
         '^repos:\n'
         '-   repo: .+shadow-repo\n'
         '    rev: .+\n'
         '    hooks:\n'
         '    -   id: bash_hook\n$',
-        config,
     )
+    config_pattern.assert_matches(config)
     assert rest == 'modified name!...........................................................Passed\n'  # noqa: E501
 
 
diff --git a/tests/error_handler_test.py b/tests/error_handler_test.py
index d066e57..6b0bb86 100644
--- a/tests/error_handler_test.py
+++ b/tests/error_handler_test.py
@@ -1,12 +1,13 @@
 import os.path
-import re
 import stat
 import sys
 from unittest import mock
 
 import pytest
+import re_assert
 
 from pre_commit import error_handler
+from pre_commit.errors import FatalError
 from pre_commit.store import Store
 from pre_commit.util import CalledProcessError
 from testing.util import cmd_output_mocked_pre_commit_home
@@ -26,27 +27,28 @@ def test_error_handler_no_exception(mocked_log_and_exit):
 
 
 def test_error_handler_fatal_error(mocked_log_and_exit):
-    exc = error_handler.FatalError('just a test')
+    exc = FatalError('just a test')
     with error_handler.error_handler():
         raise exc
 
     mocked_log_and_exit.assert_called_once_with(
         'An error has occurred',
+        1,
         exc,
         # Tested below
         mock.ANY,
     )
 
-    assert re.match(
+    pattern = re_assert.Matches(
         r'Traceback \(most recent call last\):\n'
         r'  File ".+pre_commit.error_handler.py", line \d+, in error_handler\n'
         r'    yield\n'
         r'  File ".+tests.error_handler_test.py", line \d+, '
         r'in test_error_handler_fatal_error\n'
         r'    raise exc\n'
-        r'(pre_commit\.error_handler\.)?FatalError: just a test\n',
-        mocked_log_and_exit.call_args[0][2],
+        r'(pre_commit\.errors\.)?FatalError: just a test\n',
     )
+    pattern.assert_matches(mocked_log_and_exit.call_args[0][3])
 
 
 def test_error_handler_uncaught_error(mocked_log_and_exit):
@@ -56,11 +58,12 @@ def test_error_handler_uncaught_error(mocked_log_and_exit):
 
     mocked_log_and_exit.assert_called_once_with(
         'An unexpected error has occurred',
+        3,
         exc,
         # Tested below
         mock.ANY,
     )
-    assert re.match(
+    pattern = re_assert.Matches(
         r'Traceback \(most recent call last\):\n'
         r'  File ".+pre_commit.error_handler.py", line \d+, in error_handler\n'
         r'    yield\n'
@@ -68,8 +71,8 @@ def test_error_handler_uncaught_error(mocked_log_and_exit):
         r'in test_error_handler_uncaught_error\n'
         r'    raise exc\n'
         r'ValueError: another test\n',
-        mocked_log_and_exit.call_args[0][2],
     )
+    pattern.assert_matches(mocked_log_and_exit.call_args[0][3])
 
 
 def test_error_handler_keyboardinterrupt(mocked_log_and_exit):
@@ -79,11 +82,12 @@ def test_error_handler_keyboardinterrupt(mocked_log_and_exit):
 
     mocked_log_and_exit.assert_called_once_with(
         'Interrupted (^C)',
+        130,
         exc,
         # Tested below
         mock.ANY,
     )
-    assert re.match(
+    pattern = re_assert.Matches(
         r'Traceback \(most recent call last\):\n'
         r'  File ".+pre_commit.error_handler.py", line \d+, in error_handler\n'
         r'    yield\n'
@@ -91,15 +95,20 @@ def test_error_handler_keyboardinterrupt(mocked_log_and_exit):
         r'in test_error_handler_keyboardinterrupt\n'
         r'    raise exc\n'
         r'KeyboardInterrupt\n',
-        mocked_log_and_exit.call_args[0][2],
     )
+    pattern.assert_matches(mocked_log_and_exit.call_args[0][3])
 
 
 def test_log_and_exit(cap_out, mock_store_dir):
-    with pytest.raises(SystemExit):
-        error_handler._log_and_exit(
-            'msg', error_handler.FatalError('hai'), "I'm a stacktrace",
-        )
+    tb = (
+        'Traceback (most recent call last):\n'
+        '  File "<stdin>", line 2, in <module>\n'
+        'pre_commit.errors.FatalError: hai\n'
+    )
+
+    with pytest.raises(SystemExit) as excinfo:
+        error_handler._log_and_exit('msg', 1, FatalError('hai'), tb)
+    assert excinfo.value.code == 1
 
     printed = cap_out.get()
     log_file = os.path.join(mock_store_dir, 'pre-commit.log')
@@ -108,7 +117,7 @@ def test_log_and_exit(cap_out, mock_store_dir):
     assert os.path.exists(log_file)
     with open(log_file) as f:
         logged = f.read()
-        expected = (
+        pattern = re_assert.Matches(
             r'^### version information\n'
             r'\n'
             r'```\n'
@@ -127,10 +136,12 @@ def test_log_and_exit(cap_out, mock_store_dir):
             r'```\n'
             r'\n'
             r'```\n'
-            r"I'm a stacktrace\n"
-            r'```\n'
+            r'Traceback \(most recent call last\):\n'
+            r'  File "<stdin>", line 2, in <module>\n'
+            r'pre_commit\.errors\.FatalError: hai\n'
+            r'```\n',
         )
-        assert re.match(expected, logged)
+        pattern.assert_matches(logged)
 
 
 def test_error_handler_non_ascii_exception(mock_store_dir):
@@ -163,7 +174,7 @@ def test_error_handler_no_tty(tempdir_factory):
         'from pre_commit.error_handler import error_handler\n'
         'with error_handler():\n'
         '    raise ValueError("\\u2603")\n',
-        retcode=1,
+        retcode=3,
         tempdir_factory=tempdir_factory,
         pre_commit_home=pre_commit_home,
     )
diff --git a/tests/languages/dotnet_test.py b/tests/languages/dotnet_test.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/languages/dotnet_test.py
diff --git a/tests/languages/helpers_test.py b/tests/languages/helpers_test.py
index fa493cc..669cd33 100644
--- a/tests/languages/helpers_test.py
+++ b/tests/languages/helpers_test.py
@@ -1,17 +1,66 @@
 import multiprocessing
-import os
+import os.path
 import sys
 from unittest import mock
 
 import pytest
 
 import pre_commit.constants as C
+from pre_commit import parse_shebang
 from pre_commit.languages import helpers
 from pre_commit.prefix import Prefix
 from pre_commit.util import CalledProcessError
 from testing.auto_namedtuple import auto_namedtuple
 
 
+@pytest.fixture
+def find_exe_mck():
+    with mock.patch.object(parse_shebang, 'find_executable') as mck:
+        yield mck
+
+
+@pytest.fixture
+def homedir_mck():
+    def fake_expanduser(pth):
+        assert pth == '~'
+        return os.path.normpath('/home/me')
+
+    with mock.patch.object(os.path, 'expanduser', fake_expanduser):
+        yield
+
+
+def test_exe_exists_does_not_exist(find_exe_mck, homedir_mck):
+    find_exe_mck.return_value = None
+    assert helpers.exe_exists('ruby') is False
+
+
+def test_exe_exists_exists(find_exe_mck, homedir_mck):
+    find_exe_mck.return_value = os.path.normpath('/usr/bin/ruby')
+    assert helpers.exe_exists('ruby') is True
+
+
+def test_exe_exists_false_if_shim(find_exe_mck, homedir_mck):
+    find_exe_mck.return_value = os.path.normpath('/foo/shims/ruby')
+    assert helpers.exe_exists('ruby') is False
+
+
+def test_exe_exists_false_if_homedir(find_exe_mck, homedir_mck):
+    find_exe_mck.return_value = os.path.normpath('/home/me/somedir/ruby')
+    assert helpers.exe_exists('ruby') is False
+
+
+def test_exe_exists_commonpath_raises_ValueError(find_exe_mck, homedir_mck):
+    find_exe_mck.return_value = os.path.normpath('/usr/bin/ruby')
+    with mock.patch.object(os.path, 'commonpath', side_effect=ValueError):
+        assert helpers.exe_exists('ruby') is True
+
+
+def test_exe_exists_true_when_homedir_is_slash(find_exe_mck):
+    find_exe_mck.return_value = os.path.normpath('/usr/bin/ruby')
+    with mock.patch.object(os.path, 'expanduser', return_value=os.sep):
+        assert helpers.exe_exists('ruby') is True
+
+
 def test_basic_get_default_version():
     assert helpers.basic_get_default_version() == C.DEFAULT
 
diff --git a/tests/languages/node_test.py b/tests/languages/node_test.py
index fd30046..8e52268 100644
--- a/tests/languages/node_test.py
+++ b/tests/languages/node_test.py
@@ -1,14 +1,21 @@
+import json
+import os
+import shutil
 import sys
 from unittest import mock
 
 import pytest
 
 import pre_commit.constants as C
+from pre_commit import envcontext
 from pre_commit import parse_shebang
-from pre_commit.languages.node import get_default_version
+from pre_commit.languages import node
+from pre_commit.prefix import Prefix
+from pre_commit.util import cmd_output
+from testing.util import xfailif_windows
 
 
-ACTUAL_GET_DEFAULT_VERSION = get_default_version.__wrapped__
+ACTUAL_GET_DEFAULT_VERSION = node.get_default_version.__wrapped__
 
 
 @pytest.fixture
@@ -45,3 +52,57 @@ def test_uses_default_when_node_and_npm_are_not_available(find_exe_mck):
 def test_sets_default_on_windows(find_exe_mck):
     find_exe_mck.return_value = '/path/to/exe'
     assert ACTUAL_GET_DEFAULT_VERSION() == C.DEFAULT
+
+
+@xfailif_windows  # pragma: win32 no cover
+def test_healthy_system_node(tmpdir):
+    tmpdir.join('package.json').write('{"name": "t", "version": "1.0.0"}')
+
+    prefix = Prefix(str(tmpdir))
+    node.install_environment(prefix, 'system', ())
+    assert node.healthy(prefix, 'system')
+
+
+@xfailif_windows  # pragma: win32 no cover
+def test_unhealthy_if_system_node_goes_missing(tmpdir):
+    bin_dir = tmpdir.join('bin').ensure_dir()
+    node_bin = bin_dir.join('node')
+    node_bin.mksymlinkto(shutil.which('node'))
+
+    prefix_dir = tmpdir.join('prefix').ensure_dir()
+    prefix_dir.join('package.json').write('{"name": "t", "version": "1.0.0"}')
+
+    path = ('PATH', (str(bin_dir), os.pathsep, envcontext.Var('PATH')))
+    with envcontext.envcontext((path,)):
+        prefix = Prefix(str(prefix_dir))
+        node.install_environment(prefix, 'system', ())
+        assert node.healthy(prefix, 'system')
+
+        node_bin.remove()
+        assert not node.healthy(prefix, 'system')
+
+
+@xfailif_windows  # pragma: win32 no cover
+def test_installs_without_links_outside_env(tmpdir):
+    tmpdir.join('bin/main.js').ensure().write(
+        '#!/usr/bin/env node\n'
+        '_ = require("lodash"); console.log("success!")\n',
+    )
+    tmpdir.join('package.json').write(
+        json.dumps({
+            'name': 'foo',
+            'version': '0.0.1',
+            'bin': {'foo': './bin/main.js'},
+            'dependencies': {'lodash': '*'},
+        }),
+    )
+
+    prefix = Prefix(str(tmpdir))
+    node.install_environment(prefix, 'system', ())
+    assert node.healthy(prefix, 'system')
+
+    # this directory shouldn't exist, make sure we succeed without it existing
+    cmd_output('rm', '-rf', str(tmpdir.join('node_modules')))
+
+    with node.in_env(prefix, 'system'):
+        assert cmd_output('foo')[1] == 'success!\n'
diff --git a/tests/languages/pygrep_test.py b/tests/languages/pygrep_test.py
index cabea22..d8bacc4 100644
--- a/tests/languages/pygrep_test.py
+++ b/tests/languages/pygrep_test.py
@@ -8,6 +8,9 @@ def some_files(tmpdir):
     tmpdir.join('f1').write_binary(b'foo\nbar\n')
     tmpdir.join('f2').write_binary(b'[INFO] hi\n')
     tmpdir.join('f3').write_binary(b"with'quotes\n")
+    tmpdir.join('f4').write_binary(b'foo\npattern\nbar\n')
+    tmpdir.join('f5').write_binary(b'[INFO] hi\npattern\nbar')
+    tmpdir.join('f6').write_binary(b"pattern\nbarwith'foo\n")
     with tmpdir.as_cwd():
         yield
 
@@ -23,42 +26,99 @@ def some_files(tmpdir):
         ("h'q", 1, "f3:1:with'quotes\n"),
     ),
 )
-def test_main(some_files, cap_out, pattern, expected_retcode, expected_out):
+def test_main(cap_out, pattern, expected_retcode, expected_out):
     ret = pygrep.main((pattern, 'f1', 'f2', 'f3'))
     out = cap_out.get()
     assert ret == expected_retcode
     assert out == expected_out
 
 
-def test_ignore_case(some_files, cap_out):
+@pytest.mark.usefixtures('some_files')
+def test_negate_by_line_no_match(cap_out):
+    ret = pygrep.main(('pattern\nbar', 'f4', 'f5', 'f6', '--negate'))
+    out = cap_out.get()
+    assert ret == 1
+    assert out == 'f4\nf5\nf6\n'
+
+
+@pytest.mark.usefixtures('some_files')
+def test_negate_by_line_two_match(cap_out):
+    ret = pygrep.main(('foo', 'f4', 'f5', 'f6', '--negate'))
+    out = cap_out.get()
+    assert ret == 1
+    assert out == 'f5\n'
+
+
+@pytest.mark.usefixtures('some_files')
+def test_negate_by_line_all_match(cap_out):
+    ret = pygrep.main(('pattern', 'f4', 'f5', 'f6', '--negate'))
+    out = cap_out.get()
+    assert ret == 0
+    assert out == ''
+
+
+@pytest.mark.usefixtures('some_files')
+def test_negate_by_file_no_match(cap_out):
+    ret = pygrep.main(('baz', 'f4', 'f5', 'f6', '--negate', '--multiline'))
+    out = cap_out.get()
+    assert ret == 1
+    assert out == 'f4\nf5\nf6\n'
+
+
+@pytest.mark.usefixtures('some_files')
+def test_negate_by_file_one_match(cap_out):
+    ret = pygrep.main(
+        ('foo\npattern', 'f4', 'f5', 'f6', '--negate', '--multiline'),
+    )
+    out = cap_out.get()
+    assert ret == 1
+    assert out == 'f5\nf6\n'
+
+
+@pytest.mark.usefixtures('some_files')
+def test_negate_by_file_all_match(cap_out):
+    ret = pygrep.main(
+        ('pattern\nbar', 'f4', 'f5', 'f6', '--negate', '--multiline'),
+    )
+    out = cap_out.get()
+    assert ret == 0
+    assert out == ''
+
+
+@pytest.mark.usefixtures('some_files')
+def test_ignore_case(cap_out):
     ret = pygrep.main(('--ignore-case', 'info', 'f1', 'f2', 'f3'))
     out = cap_out.get()
     assert ret == 1
     assert out == 'f2:1:[INFO] hi\n'
 
 
-def test_multiline(some_files, cap_out):
+@pytest.mark.usefixtures('some_files')
+def test_multiline(cap_out):
     ret = pygrep.main(('--multiline', r'foo\nbar', 'f1', 'f2', 'f3'))
     out = cap_out.get()
     assert ret == 1
     assert out == 'f1:1:foo\nbar\n'
 
 
-def test_multiline_line_number(some_files, cap_out):
+@pytest.mark.usefixtures('some_files')
+def test_multiline_line_number(cap_out):
     ret = pygrep.main(('--multiline', r'ar', 'f1', 'f2', 'f3'))
     out = cap_out.get()
     assert ret == 1
     assert out == 'f1:2:bar\n'
 
 
-def test_multiline_dotall_flag_is_enabled(some_files, cap_out):
+@pytest.mark.usefixtures('some_files')
+def test_multiline_dotall_flag_is_enabled(cap_out):
     ret = pygrep.main(('--multiline', r'o.*bar', 'f1', 'f2', 'f3'))
     out = cap_out.get()
     assert ret == 1
     assert out == 'f1:1:foo\nbar\n'
 
 
-def test_multiline_multiline_flag_is_enabled(some_files, cap_out):
+@pytest.mark.usefixtures('some_files')
+def test_multiline_multiline_flag_is_enabled(cap_out):
     ret = pygrep.main(('--multiline', r'foo$.*bar', 'f1', 'f2', 'f3'))
     out = cap_out.get()
     assert ret == 1
diff --git a/tests/languages/python_test.py b/tests/languages/python_test.py
index 29c5a9b..cfe1483 100644
--- a/tests/languages/python_test.py
+++ b/tests/languages/python_test.py
@@ -36,13 +36,14 @@ def test_norm_version_expanduser():
 
 
 def test_norm_version_of_default_is_sys_executable():
-    assert python.norm_version('default') == os.path.realpath(sys.executable)
+    assert python.norm_version('default') is None
 
 
 @pytest.mark.parametrize('v', ('python3.6', 'python3', 'python'))
 def test_sys_executable_matches(v):
     with mock.patch.object(sys, 'version_info', (3, 6, 7)):
         assert python._sys_executable_matches(v)
+        assert python.norm_version(v) is None
 
 
 @pytest.mark.parametrize('v', ('notpython', 'python3.x'))
diff --git a/tests/languages/ruby_test.py b/tests/languages/ruby_test.py
index 853bb73..6c0c9e5 100644
--- a/tests/languages/ruby_test.py
+++ b/tests/languages/ruby_test.py
@@ -30,23 +30,45 @@ def test_uses_system_if_both_gem_and_ruby_are_available(find_exe_mck):
     assert ACTUAL_GET_DEFAULT_VERSION() == 'system'
 
 
+@pytest.fixture
+def fake_gem_prefix(tmpdir):
+    gemspec = '''\
+Gem::Specification.new do |s|
+    s.name = 'pre_commit_dummy_package'
+    s.version = '0.0.0'
+    s.summary = 'dummy gem for pre-commit hooks'
+    s.authors = ['Anthony Sottile']
+end
+'''
+    tmpdir.join('dummy_gem.gemspec').write(gemspec)
+    yield Prefix(tmpdir)
+
+
+@xfailif_windows  # pragma: win32 no cover
+def test_install_ruby_system(fake_gem_prefix):
+    ruby.install_environment(fake_gem_prefix, 'system', ())
+
+    # Should be able to activate and use rbenv install
+    with ruby.in_env(fake_gem_prefix, 'system'):
+        _, out, _ = cmd_output('gem', 'list')
+        assert 'pre_commit_dummy_package' in out
+
+
 @xfailif_windows  # pragma: win32 no cover
-def test_install_rbenv(tempdir_factory):
-    prefix = Prefix(tempdir_factory.get())
-    ruby._install_rbenv(prefix, C.DEFAULT)
+def test_install_ruby_default(fake_gem_prefix):
+    ruby.install_environment(fake_gem_prefix, C.DEFAULT, ())
     # Should have created rbenv directory
-    assert os.path.exists(prefix.path('rbenv-default'))
+    assert os.path.exists(fake_gem_prefix.path('rbenv-default'))
 
     # Should be able to activate using our script and access rbenv
-    with ruby.in_env(prefix, 'default'):
+    with ruby.in_env(fake_gem_prefix, 'default'):
         cmd_output('rbenv', '--help')
 
 
 @xfailif_windows  # pragma: win32 no cover
-def test_install_rbenv_with_version(tempdir_factory):
-    prefix = Prefix(tempdir_factory.get())
-    ruby._install_rbenv(prefix, version='1.9.3p547')
+def test_install_ruby_with_version(fake_gem_prefix):
+    ruby.install_environment(fake_gem_prefix, '2.7.2', ())
 
     # Should be able to activate and use rbenv install
-    with ruby.in_env(prefix, '1.9.3p547'):
+    with ruby.in_env(fake_gem_prefix, '2.7.2'):
         cmd_output('rbenv', 'install', '--help')
diff --git a/tests/main_test.py b/tests/main_test.py
index f7abeeb..6738df6 100644
--- a/tests/main_test.py
+++ b/tests/main_test.py
@@ -6,7 +6,7 @@ import pytest
 
 import pre_commit.constants as C
 from pre_commit import main
-from pre_commit.error_handler import FatalError
+from pre_commit.errors import FatalError
 from testing.auto_namedtuple import auto_namedtuple
 
 
diff --git a/tests/repository_test.py b/tests/repository_test.py
index 84e4da9..3d5093d 100644
--- a/tests/repository_test.py
+++ b/tests/repository_test.py
@@ -1,5 +1,4 @@
 import os.path
-import re
 import shutil
 import sys
 from typing import Any
@@ -8,6 +7,7 @@ from unittest import mock
 
 import cfgv
 import pytest
+import re_assert
 
 import pre_commit.constants as C
 from pre_commit.clientlib import CONFIG_SCHEMA
@@ -31,6 +31,7 @@ from testing.fixtures import make_repo
 from testing.fixtures import modify_manifest
 from testing.util import cwd
 from testing.util import get_resource_path
+from testing.util import skipif_cant_run_coursier
 from testing.util import skipif_cant_run_docker
 from testing.util import skipif_cant_run_swift
 from testing.util import xfailif_windows
@@ -94,8 +95,8 @@ def test_conda_with_additional_dependencies_hook(tempdir_factory, store):
         config_kwargs={
             'hooks': [{
                 'id': 'additional-deps',
-                'args': ['-c', 'import mccabe; print("OK")'],
-                'additional_dependencies': ['mccabe'],
+                'args': ['-c', 'import tzdata; print("OK")'],
+                'additional_dependencies': ['python-tzdata'],
             }],
         },
     )
@@ -109,8 +110,8 @@ def test_local_conda_additional_dependencies(store):
             'name': 'local-conda',
             'entry': 'python',
             'language': 'conda',
-            'args': ['-c', 'import mccabe; print("OK")'],
-            'additional_dependencies': ['mccabe'],
+            'args': ['-c', 'import tzdata; print("OK")'],
+            'additional_dependencies': ['python-tzdata'],
         }],
     }
     hook = _get_hook(config, store, 'local-conda')
@@ -195,6 +196,15 @@ def test_versioned_python_hook(tempdir_factory, store):
     )
 
 
+@skipif_cant_run_coursier  # pragma: win32 no cover
+def test_run_a_coursier_hook(tempdir_factory, store):
+    _test_hook_repo(
+        tempdir_factory, store, 'coursier_hooks_repo',
+        'echo-java',
+        ['Hello World from coursier'], b'Hello World from coursier\n',
+    )
+
+
 @skipif_cant_run_docker  # pragma: win32 no cover
 def test_run_a_docker_hook(tempdir_factory, store):
     _test_hook_repo(
@@ -843,12 +853,12 @@ def test_too_new_version(tempdir_factory, store, fake_log_handler):
     with pytest.raises(SystemExit):
         _get_hook(config, store, 'bash_hook')
     msg = fake_log_handler.handle.call_args[0][0].msg
-    assert re.match(
+    pattern = re_assert.Matches(
         r'^The hook `bash_hook` requires pre-commit version 999\.0\.0 but '
         r'version \d+\.\d+\.\d+ is installed.  '
         r'Perhaps run `pip install --upgrade pre-commit`\.$',
-        msg,
     )
+    pattern.assert_matches(msg)
 
 
 @pytest.mark.parametrize('version', ('0.1.0', C.VERSION))
@@ -917,3 +927,17 @@ def test_local_perl_additional_dependencies(store):
     ret, out = _hook_run(hook, (), color=False)
     assert ret == 0
     assert _norm_out(out).startswith(b'This is perltidy, v20200110')
+
+
+@pytest.mark.parametrize(
+    'repo',
+    (
+        'dotnet_hooks_csproj_repo',
+        'dotnet_hooks_sln_repo',
+    ),
+)
+def test_dotnet_hook(tempdir_factory, store, repo):
+    _test_hook_repo(
+        tempdir_factory, store, repo,
+        'dotnet example hook', [], b'Hello from dotnet!\n',
+    )
diff --git a/tests/xargs_test.py b/tests/xargs_test.py
index 1fc9207..4f6136e 100644
--- a/tests/xargs_test.py
+++ b/tests/xargs_test.py
@@ -160,7 +160,7 @@ def test_xargs_concurrency():
     assert ret == 0
     pids = stdout.splitlines()
     assert len(pids) == 5
-    # It would take 0.5*5=2.5 seconds ot run all of these in serial, so if it
+    # It would take 0.5*5=2.5 seconds to run all of these in serial, so if it
     # takes less, they must have run concurrently.
     assert elapsed < 2.5