Improve unit test coverage (#453)

Improves and fixes some existing unit tests.
Adds a few new tests.

15 files changed, 98 insertions, 29 deletions

diff --git a/gitlint-core/gitlint/__init__.py b/gitlint-core/gitlint/__init__.py
index d08993f..a2339fd 100644
--- a/gitlint-core/gitlint/__init__.py
+++ b/gitlint-core/gitlint/__init__.py
@@ -1,8 +1,8 @@
 import sys
 
 if sys.version_info >= (3, 8):
-    from importlib import metadata
+    from importlib import metadata  # pragma: nocover
 else:
-    import importlib_metadata as metadata
+    import importlib_metadata as metadata  # pragma: nocover
 
 __version__ = metadata.version("gitlint-core")
diff --git a/gitlint-core/gitlint/git.py b/gitlint-core/gitlint/git.py
index 405d1ab..6612a7d 100644
--- a/gitlint-core/gitlint/git.py
+++ b/gitlint-core/gitlint/git.py
@@ -171,11 +171,6 @@ class GitChangedFileStats:
     def __str__(self) -> str:
         return f"{self.filepath}: {self.additions} additions, {self.deletions} deletions"
 
-    def __repr__(self) -> str:
-        return (
-            f'GitChangedFileStats(filepath="{self.filepath}", additions={self.additions}, deletions={self.deletions})'
-        )
-
 
 class GitCommit:
     """Class representing a git commit.
diff --git a/gitlint-core/gitlint/rule_finder.py b/gitlint-core/gitlint/rule_finder.py
index 4179c9e..810faa9 100644
--- a/gitlint-core/gitlint/rule_finder.py
+++ b/gitlint-core/gitlint/rule_finder.py
@@ -137,6 +137,7 @@ def assert_valid_rule_class(clazz, rule_type="User-defined"):  # noqa: PLR0912 (
     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):
diff --git a/gitlint-core/gitlint/tests/base.py b/gitlint-core/gitlint/tests/base.py
index 326c7cb..3899a5f 100644
--- a/gitlint-core/gitlint/tests/base.py
+++ b/gitlint-core/gitlint/tests/base.py
@@ -171,16 +171,18 @@ class BaseTestCase(unittest.TestCase):
             yield
         except expected_exception as exc:
             exception_msg = str(exc)
-            if exception_msg != expected_msg:
+            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:
+        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")
+        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.
diff --git a/gitlint-core/gitlint/tests/cli/test_cli.py b/gitlint-core/gitlint/tests/cli/test_cli.py
index 540800d..c006375 100644
--- a/gitlint-core/gitlint/tests/cli/test_cli.py
+++ b/gitlint-core/gitlint/tests/cli/test_cli.py
@@ -101,6 +101,40 @@ class CLITests(BaseTestCase):
 
     @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"""
 
@@ -600,6 +634,11 @@ class CLITests(BaseTestCase):
         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"""
diff --git a/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py b/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py
index 5cc3355..2bad2ed 100644
--- a/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py
+++ b/gitlint-core/gitlint/tests/contrib/rules/test_authors_commit.py
@@ -101,6 +101,5 @@ class ContribAuthorsCommitTests(BaseTestCase):
         return_value=False,
     )
     def test_read_authors_file_missing_file(self, _mock_iterdir):
-        with self.assertRaises(FileNotFoundError) as err:
+        with self.assertRaisesMessage(FileNotFoundError, "No AUTHORS file found!"):
             AllowedAuthors._read_authors_from_file(self.gitcontext)
-            self.assertEqual(err.exception.args[0], "AUTHORS file not found")
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/rules/test_configuration_rules.py b/gitlint-core/gitlint/tests/rules/test_configuration_rules.py
index d5b70a9..5935a4a 100644
--- a/gitlint-core/gitlint/tests/rules/test_configuration_rules.py
+++ b/gitlint-core/gitlint/tests/rules/test_configuration_rules.py
@@ -105,6 +105,12 @@ class ConfigurationRuleTests(BaseTestCase):
         ]
         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()
diff --git a/gitlint-core/gitlint/tests/rules/test_rules.py b/gitlint-core/gitlint/tests/rules/test_rules.py
index e24d91a..b401372 100644
--- a/gitlint-core/gitlint/tests/rules/test_rules.py
+++ b/gitlint-core/gitlint/tests/rules/test_rules.py
@@ -3,6 +3,10 @@ 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
@@ -13,9 +17,16 @@ class RuleTests(BaseTestCase):
 
     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_user_rules.py b/gitlint-core/gitlint/tests/rules/test_user_rules.py
index c2309a6..8086bea 100644
--- a/gitlint-core/gitlint/tests/rules/test_user_rules.py
+++ b/gitlint-core/gitlint/tests/rules/test_user_rules.py
@@ -103,21 +103,21 @@ class UserRuleTests(BaseTestCase):
             target = rules.CommitMessageTitle
 
             def validate(self):
-                pass
+                pass  # pragma: nocover
 
         class MyCommitRuleClass(rules.CommitRule):
             id = "UC2"
             name = "my-cömmit-rule"
 
             def validate(self):
-                pass
+                pass  # pragma: nocover
 
         class MyConfigurationRuleClass(rules.ConfigurationRule):
             id = "UC3"
             name = "my-cönfiguration-rule"
 
             def apply(self):
-                pass
+                pass  # pragma: nocover
 
         # Just assert that no error is raised
         self.assertIsNone(assert_valid_rule_class(MyLineRuleClass))
@@ -235,8 +235,8 @@ class UserRuleTests(BaseTestCase):
         with self.assertRaisesMessage(UserRuleError, expected_msg):
             assert_valid_rule_class(MyRuleClass)
 
-        # validate attribute - not a method
-        MyRuleClass.validate = "föo"
+        # apply attribute - not a method
+        MyRuleClass.apply = "föo"
         with self.assertRaisesMessage(UserRuleError, expected_msg):
             assert_valid_rule_class(MyRuleClass)
 
@@ -246,7 +246,7 @@ class UserRuleTests(BaseTestCase):
             name = "my-rüle-class"
 
             def validate(self):
-                pass
+                pass  # pragma: nocover
 
         # no target
         expected_msg = (
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
index 6291e80..c947250 100644
--- a/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.py
+++ b/gitlint-core/gitlint/tests/samples/user_rules/my_commit_rules.py
@@ -19,7 +19,7 @@ class MyUserCommitRule(CommitRule):
 
 
 def func_should_be_ignored():
-    pass
+    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
index 22c3f65..c2863fe 100644
--- a/gitlint-core/gitlint/tests/samples/user_rules/parent_package/__init__.py
+++ b/gitlint-core/gitlint/tests/samples/user_rules/parent_package/__init__.py
@@ -9,4 +9,4 @@ class InitFileRule(CommitRule):
     options_spec = []
 
     def validate(self, _commit):
-        return []
+        return []  # pragma: nocover
diff --git a/gitlint-core/gitlint/tests/test_hooks.py b/gitlint-core/gitlint/tests/test_hooks.py
index 8007009..7390f14 100644
--- a/gitlint-core/gitlint/tests/test_hooks.py
+++ b/gitlint-core/gitlint/tests/test_hooks.py
@@ -57,9 +57,10 @@ class HookTests(BaseTestCase):
         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()
+
+        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
@@ -105,9 +106,10 @@ class HookTests(BaseTestCase):
         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()
+
+        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
@@ -116,9 +118,10 @@ class HookTests(BaseTestCase):
         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()
+
+        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
diff --git a/gitlint-core/gitlint/tests/test_options.py b/gitlint-core/gitlint/tests/test_options.py
index 9b84945..deff723 100644
--- a/gitlint-core/gitlint/tests/test_options.py
+++ b/gitlint-core/gitlint/tests/test_options.py
@@ -14,6 +14,10 @@ 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,
diff --git a/pyproject.toml b/pyproject.toml
index cfc6c50..98b60f5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -199,3 +199,4 @@ branch = true # measure branch coverage in addition to statement coverage
 
 [tool.coverage.report]
 fail_under = 97
+show_missing = true