Recognize stub ``pyi`` Python files. (#2182)HEADmain

Recognize stub ``pyi`` Python files.

Refs pylint-dev/pylint#4987

Co-authored-by: Jacob Walls <jacobtylerwalls@gmail.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/astroid/modutils.py b/astroid/modutils.py
index b4f3b6e3..33fd3eeb 100644
--- a/astroid/modutils.py
+++ b/astroid/modutils.py
@@ -44,10 +44,10 @@ logger = logging.getLogger(__name__)
 
 
 if sys.platform.startswith("win"):
-    PY_SOURCE_EXTS = ("py", "pyw")
+    PY_SOURCE_EXTS = ("py", "pyw", "pyi")
     PY_COMPILED_EXTS = ("dll", "pyd")
 else:
-    PY_SOURCE_EXTS = ("py",)
+    PY_SOURCE_EXTS = ("py", "pyi")
     PY_COMPILED_EXTS = ("so",)
 
 
@@ -274,9 +274,6 @@ def _get_relative_base_path(filename: str, path_to_check: str) -> list[str] | No
     if os.path.normcase(real_filename).startswith(path_to_check):
         importable_path = real_filename
 
-    # if "var" in path_to_check:
-    #     breakpoint()
-
     if importable_path:
         base_path = os.path.splitext(importable_path)[0]
         relative_base_path = base_path[len(path_to_check) :]
@@ -476,7 +473,7 @@ def get_module_files(
             continue
         _handle_blacklist(blacklist, dirnames, filenames)
         # check for __init__.py
-        if not list_all and "__init__.py" not in filenames:
+        if not list_all and {"__init__.py", "__init__.pyi"}.isdisjoint(filenames):
             dirnames[:] = ()
             continue
         for filename in filenames:
@@ -499,6 +496,8 @@ def get_source_file(filename: str, include_no_ext: bool = False) -> str:
     """
     filename = os.path.abspath(_path_from_filename(filename))
     base, orig_ext = os.path.splitext(filename)
+    if orig_ext == ".pyi" and os.path.exists(f"{base}{orig_ext}"):
+        return f"{base}{orig_ext}"
     for ext in PY_SOURCE_EXTS:
         source_path = f"{base}.{ext}"
         if os.path.exists(source_path):
@@ -663,7 +662,7 @@ def _is_python_file(filename: str) -> bool:
 
     .pyc and .pyo are ignored
     """
-    return filename.endswith((".py", ".so", ".pyd", ".pyw"))
+    return filename.endswith((".py", ".pyi", ".so", ".pyd", ".pyw"))
 
 
 def _has_init(directory: str) -> str | None: