chore(ruff): Fix linting issues

src/doctest_docutils.py:137:31: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
src/doctest_docutils.py:141:31: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
src/doctest_docutils.py:145:31: RUF012 Mutable class attributes should be annotated with `typing.ClassVar`
src/doctest_docutils.py:398:15: TRY003 Avoid specifying long messages outside the exception class
src/doctest_docutils.py:408:16: PTH119 `os.path.basename()` should be replaced by `Path.name`
tests/test_doctest_docutils.py:206:15: TRY003 Avoid specifying long messages outside the exception class

src/doctest_docutils.py

@@ -134,15 +134,15 @@ def run(self) -> t.List[Node]:
 
 
 class TestsetupDirective(TestDirective):
-    option_spec: OptionSpec = {"skipif": directives.unchanged_required}
+    option_spec: t.ClassVar[OptionSpec] = {"skipif": directives.unchanged_required}
 
 
 class TestcleanupDirective(TestDirective):
-    option_spec: OptionSpec = {"skipif": directives.unchanged_required}
+    option_spec: t.ClassVar[OptionSpec] = {"skipif": directives.unchanged_required}
 
 
 class DoctestDirective(TestDirective):
-    option_spec: OptionSpec = {
+    option_spec: t.ClassVar[OptionSpec] = {
         "hide": directives.flag,
         "no-trim-doctest-flags": directives.flag,
         "options": directives.unchanged,
@@ -374,6 +374,13 @@ def _get_test(
         return self._parser.get_doctest(string, globs, name, filename, lineno)
 
 
+class TestDocutilsPackageRelativeError(Exception):
+    def __init__(self):
+        return super().__init__(
+            "Package may only be specified for module-relative paths."
+        )
+
+
 def testdocutils(
     filename: str,
     module_relative: bool = True,
@@ -395,7 +402,7 @@ def testdocutils(
     global master
 
     if package and not module_relative:
-        raise ValueError("Package may only be specified for module-" "relative paths.")
+        raise TestDocutilsPackageRelativeError()
 
     # Keep the absolute file paths. This is needed for Include directies to work.
     # The absolute path will be applied to source_path when creating the docutils doc.
@@ -405,7 +412,7 @@ def testdocutils(
 
     # If no name was given, then use the file's name.
     if name is None:
-        name = os.path.basename(filename)
+        name = pathlib.Path(filename).stem
 
     # Assemble the globals.
     globs = {} if globs is None else globs.copy()

tests/test_doctest_docutils.py

@@ -184,6 +184,11 @@ class DocTestFinderFixture(t.NamedTuple):
 ]
 
 
+class FilePathModeNotImplemented(Exception):
+    def __init__(self, file_path_mode: str) -> None:
+        return super().__init__(f"No file_path_mode supported for {file_path_mode}")
+
+
 @pytest.mark.parametrize(
     DocTestFinderFixture._fields, FIXTURES, ids=[f.test_id for f in FIXTURES]
 )
@@ -203,7 +208,7 @@ def test_DocutilsDocTestFinder(
     if file_path_mode == "absolute":
         first_test_filename = str(tests_path / first_test_filename)
     elif file_path_mode != "relative":
-        raise NotImplementedError(f"No file_path_mode supported for {file_path_mode}")
+        raise FilePathModeNotImplemented(file_path_mode)
 
     tests_path.mkdir()
     for file_name, text in files.items():