Ignore from ... import * imports in stub files (#153)

* Ignore `from ... import *` imports in stub files

* avoiding unnecessary  calls.

* Testing star imports with stub file-path.

* Run prettier over docs/README.md via pre-commit.

Co-authored-by: Hadi Alqattan <alqattanhadizaki@gmail.com>

docs/CHANGELOG.md

@@ -10,6 +10,10 @@ this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- [Pycln skips `from foo import *` imports in compliance with PEP 484 in stub files (`.pyi`) by @AlexWaygood](https://github.com/hadialqattan/pycln/pull/153)
+
 ### Changed
 
 - [Bump typer from 0.4.1 to 0.5.0 by @dependabot[bot]](https://github.com/hadialqattan/pycln/pull/151)

docs/README.md

@@ -1093,7 +1093,9 @@ both the developers and QA tools.
 
 > Pycln skips redundant alias imports in compliance with
 > [PEP 484](https://peps.python.org/pep-0484/#stub-files) for the purposes of exporting
-> modules and symbols for static type checking.
+> modules and symbols for static type checking. Additionally, all symbols imported using
+> `from foo import *` imports are considered publicly exported in a stub file, so these
+> import statements are also ignored for `.pyi` extensions.
 
 - case a:
 
@@ -1102,10 +1104,16 @@ both the developers and QA tools.
   ```
 
 - case b:
+
   ```python
   from X import Y as Y  # marked as used.
   ```
 
+- case c:
+  ```python
+  from socket import *  # marked as used.
+  ```
+
 # Unsupported Cases
 
 ## Specific

pycln/utils/refactor.py

@@ -393,6 +393,14 @@ def _expand_import_star(
             is_star = False
             if node.names[0].name == "*":
 
+                #: [for `.pyi` files] PEP 484 - Star Imports rule:
+                #:
+                #: >>> from X import *  # exported (should be treated as used)
+                #:
+                #: More info: https://peps.python.org/pep-0484/#stub-files
+                if self._path.is_stub:
+                    return node, None
+
                 if node.module:
                     if node.module.split(".")[0] in self.configs.skip_imports:
                         return node, None
@@ -433,7 +441,7 @@ def _should_remove(
         real_name = node.module if isinstance(node, ImportFrom) else alias.name
         used_name = alias.asname if alias.asname else alias.name
 
-        #: (for `.pyi`) PEP 484 - Redundant Module/Symbol Aliases rule:
+        #: [for `.pyi` files] PEP 484 - Redundant Module/Symbol Aliases rule:
         #:
         #: >>> import X as X  # exported (should be treated as used)
         #:

tests/test_refactor.py

@@ -837,16 +837,18 @@ def test_transform(
             assert fixed_lines == updated_lines
 
     @pytest.mark.parametrize(
-        "expand_import_star_raise, name, expec_is_star",
+        "expand_import_star_raise, name, is_stub, expec_is_star",
         [
-            pytest.param(None, "*", True, id="star"),
-            pytest.param(None, "!*", False, id="not-star"),
+            pytest.param(None, "*", False, True, id="star"),
+            pytest.param(None, "!*", False, False, id="not-star"),
             pytest.param(
                 UnexpandableImportStar(Path(""), NodeLocation((1, 0), 1), ""),
                 "*",
+                False,
                 None,
                 id="not-star",
             ),
+            pytest.param(None, "*", True, None, id="star-stub(pyi)"),
         ],
     )
     @mock.patch(MOCK % "scan.expand_import_star")
@@ -855,11 +857,14 @@ def test_expand_import_star(
         expand_import_star,
         expand_import_star_raise,
         name,
+        is_stub,
         expec_is_star,
     ):
         node = ImportFrom(NodeLocation((1, 0), 1), [ast.alias(name=name)], "xxx", 0)
         expand_import_star.return_value = node
         expand_import_star.side_effect = expand_import_star_raise
+        if is_stub:
+            self.session_maker._path = refactor.PyPath("stub.pyi")
         enode, is_star = self.session_maker._expand_import_star(node)
         assert (enode, is_star) == (node, expec_is_star)