Check for future import

Author: cdce8p

pylint/extensions/typing.py

@@ -7,6 +7,7 @@
 from pylint.checkers.utils import (
     check_messages,
     is_node_in_type_annotation_context,
+    is_postponed_evaluation_enabled,
     safe_infer,
 )
 from pylint.interfaces import INFERENCE, IAstroidChecker
@@ -307,6 +308,11 @@ def _check_broken_noreturn(self, node: Union[nodes.Name, nodes.Attribute]) -> No
             # NoReturn not part of a Union or Callable type
             return
 
+        if is_postponed_evaluation_enabled(node) and is_node_in_type_annotation_context(
+            node
+        ):
+            return
+
         for inferred in node.infer():
             # To deal with typing_extensions, don't use safe_infer
             if (

tests/functional/ext/typing/typing_broken_noreturn_future_import.py

@@ -0,0 +1,37 @@
+"""
+'typing.NoReturn' is broken inside compond types for Python 3.7.0
+https://bugs.python.org/issue34921
+
+If no runtime introspection is required, use string annotations instead.
+
+With 'from __future__ import annotations', only emit errors for nodes
+not in a type annotation context.
+"""
+# pylint: disable=missing-docstring
+from __future__ import annotations
+
+import typing
+from typing import Callable, NoReturn, Union
+
+import typing_extensions
+
+
+def func1() -> NoReturn:
+    raise Exception
+
+def func2() -> Union[None, NoReturn]:
+    pass
+
+def func3() -> Union[None, "NoReturn"]:
+    pass
+
+def func4() -> Union[None, typing.NoReturn]:
+    pass
+
+def func5() -> Union[None, typing_extensions.NoReturn]:
+    pass
+
+
+Alias1 = NoReturn
+Alias2 = Callable[..., NoReturn]  # [broken-noreturn]
+Alias3 = Callable[..., "NoReturn"]

tests/functional/ext/typing/typing_broken_noreturn_future_import.rc

@@ -0,0 +1,3 @@
+[master]
+py-version=3.7
+load-plugins=pylint.extensions.typing

tests/functional/ext/typing/typing_broken_noreturn_future_import.txt

@@ -0,0 +1 @@
+broken-noreturn:33:23:33:31::'NoReturn' inside compound types is broken in 3.7.0 / 3.7.1:INFERENCE