Merge branch 'master' into infer-upper-bound

python · ilevkivskyi · Sep 27, 2023 · Sep 25, 2023 · Sep 26, 2023 · Sep 26, 2023
commit 5a3d0f11151689308a9ea09b1f9c68a1591290cb
diff --git a/test-data/unit/check-inference.test b/test-data/unit/check-inference.test
@@ -3719,3 +3719,28 @@ ABT = TypeVar("ABT", bound=Union[A, B])
 
 def simpler(k: ABT):
     foo(k)
+
+
+[case testInferenceWorksWithEmptyCollectionsNested]
+from typing import List, TypeVar, NoReturn
+T = TypeVar('T')
+def f(a: List[T], b: List[T]) -> T: pass
+x = ["yes"]
+reveal_type(f(x, []))  # N: Revealed type is "builtins.str"
+reveal_type(f(["yes"], []))  # N: Revealed type is "builtins.str"
+
+empty: List[NoReturn]
+f(x, empty)  # E: Cannot infer type argument 1 of "f"
+f(["no"], empty)  # E: Cannot infer type argument 1 of "f"
+[builtins fixtures/list.pyi]
+
+[case testInferenceWorksWithEmptyCollectionsUnion]
+from typing import Any, Dict, NoReturn, NoReturn, Union
+
+def foo() -> Union[Dict[str, Any], Dict[int, Any]]:
+    return {}
+
+empty: Dict[NoReturn, NoReturn]
+def bar() -> Union[Dict[str, Any], Dict[int, Any]]:
+    return empty
+[builtins fixtures/dict.pyi]