Discover .pyi files (#9241)

.pyenchant_pylint_custom_dict.txt

@@ -261,6 +261,7 @@ proc
 py
 pyenchant
 pyfile
+pyi
 pylint
 pylintdict
 pylintrc

doc/whatsnew/fragments/9097.feature

@@ -0,0 +1,5 @@
+Discover ``.pyi`` files when linting.
+
+These can be ignored with the ``ignore-patterns`` setting.
+
+Closes #9097

pylint/lint/pylinter.py

@@ -584,8 +584,8 @@ def prepare_checkers(self) -> list[BaseChecker]:
     def should_analyze_file(modname: str, path: str, is_argument: bool = False) -> bool:
         """Returns whether a module should be checked.
 
-        This implementation returns True for all python source file, indicating
-        that all files should be linted.
+        This implementation returns True for all python source files (.py and .pyi),
+        indicating that all files should be linted.
 
         Subclasses may override this method to indicate that modules satisfying
         certain conditions should not be linted.
@@ -599,7 +599,7 @@ def should_analyze_file(modname: str, path: str, is_argument: bool = False) -> b
         """
         if is_argument:
             return True
-        return path.endswith(".py")
+        return path.endswith((".py", ".pyi"))
 
     # pylint: enable=unused-argument
 
@@ -646,7 +646,7 @@ def _discover_files(self, files_or_modules: Sequence[str]) -> Iterator[str]:
                         yield from (
                             os.path.join(root, file)
                             for file in files
-                            if file.endswith(".py")
+                            if file.endswith((".py", ".pyi"))
                         )
             else:
                 yield something

tests/lint/unittest_lint.py

@@ -1047,6 +1047,28 @@ def test_by_module_statement_value(initialized_linter: PyLinter) -> None:
         assert module_stats["statement"] == linter2.stats.statement
 
 
+def test_finds_pyi_file() -> None:
+    run = Run(
+        [join(REGRTEST_DATA_DIR, "pyi")],
+        exit=False,
+    )
+    assert run.linter.current_file is not None
+    assert run.linter.current_file.endswith("foo.pyi")
+
+
+def test_recursive_finds_pyi_file() -> None:
+    run = Run(
+        [
+            "--recursive",
+            "y",
+            join(REGRTEST_DATA_DIR, "pyi"),
+        ],
+        exit=False,
+    )
+    assert run.linter.current_file is not None
+    assert run.linter.current_file.endswith("foo.pyi")
+
+
 @pytest.mark.parametrize(
     "ignore_parameter,ignore_parameter_value",
     [

tests/regrtest_data/pyi/foo.pyi

@@ -0,0 +1 @@
+foo = 1