Merge pull request #3868 from luigibertaco/from_future_annotations_as

bugfix: accepts aliases for __future__ annotations

CONTRIBUTORS.txt

@@ -412,6 +412,8 @@ contributors:
 
 * David Cain: contributor
 
+* Luigi Bertaco Cristofolini (luigibertaco): contributor
+
 * Or Bahari
 
 * Joshua Cannon: contributor

ChangeLog

@@ -38,6 +38,10 @@ Release date: TBA
 
 * Fix AttributeError in checkers/refactoring.py
 
+* Fix a bug with postponed evaluation when using aliases for annotations.
+
+  Close #3798
+
 * Fix minor documentation issues
 
 What's New in Pylint 2.6.0?

pylint/checkers/utils.py

@@ -1262,14 +1262,8 @@ def get_node_last_lineno(node: astroid.node_classes.NodeNG) -> int:
 
 def is_postponed_evaluation_enabled(node: astroid.node_classes.NodeNG) -> bool:
     """Check if the postponed evaluation of annotations is enabled"""
-    name = "annotations"
     module = node.root()
-    stmt = module.locals.get(name)
-    return (
-        stmt
-        and isinstance(stmt[0], astroid.ImportFrom)
-        and stmt[0].modname == "__future__"
-    )
+    return "annotations" in module.future_imports
 
 
 def is_subclass_of(child: astroid.ClassDef, parent: astroid.ClassDef) -> bool:

tests/functional/p/postponed_evaluation_activated_with_alias.py

@@ -0,0 +1,28 @@
+# pylint: disable=missing-docstring,no-self-use,unused-argument,pointless-statement
+# pylint: disable=too-few-public-methods,no-name-in-module
+from __future__ import annotations as __annotations__
+
+
+class MyClass:
+    @classmethod
+    def from_string(cls, source) -> MyClass:
+        ...
+
+    def validate_b(self, obj: OtherClass) -> bool:
+        ...
+
+
+class OtherClass:
+    ...
+
+
+class Example:
+    obj: Other
+
+
+class Other:
+    ...
+
+
+class ExampleSelf:
+    next: ExampleSelf

tests/functional/p/postponed_evaluation_activated_with_alias.rc

@@ -0,0 +1,2 @@
+[testoptions]
+min_pyver=3.7