Changed behavior to allow a value with type _AnnotatedAlias to be u…

…sed with an implicit `__getitem__` call even though this type is not documented or declared in typeshed. This addresses #8916.
microsoft · Sep 6, 2024 · 8191861 · 8191861
1 parent 05435ba
commit 8191861
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Showing 4 changed files with 11 additions and 2 deletions.
diff --git a/packages/pyright-internal/src/analyzer/typeEvaluator.ts b/packages/pyright-internal/src/analyzer/typeEvaluator.ts
@@ -4776,6 +4776,14 @@ export function createTypeEvaluator(
             return type;
         }
 
+        // If this is a type alias and we are not supposed to specialize it, return it as is.
+        if ((flags & EvalFlags.NoSpecialize) !== 0 && type.props?.typeAliasInfo) {
+            // Special-case TypeAliasType which should be converted in this case.
+            if (!ClassType.isBuiltIn(type.props.specialForm, 'TypeAliasType')) {
+                return type;
+            }
+        }
+
         if (type.props?.typeForm) {
             return TypeBase.cloneWithTypeForm(type.props.specialForm, type.props.typeForm);
         }

diff --git a/packages/pyright-internal/src/tests/samples/annotated1.py b/packages/pyright-internal/src/tests/samples/annotated1.py
@@ -54,6 +54,7 @@ def func2(a: TypeWithStringArg):
 Param = Annotated[_T, "x"]
 
 x1: Param[int] = 3
+print(Param[int])
 
 
 class A:

diff --git a/packages/pyright-internal/src/tests/samples/typeAlias1.py b/packages/pyright-internal/src/tests/samples/typeAlias1.py
@@ -23,7 +23,7 @@ class A:
     Value2 = 1
 
 
-reveal_type(A.Value1, expected_text="type[Literal]")
+reveal_type(A.Value1, expected_text="type[Literal[1]]")
 reveal_type(A.Value2, expected_text="int")
 
 

diff --git a/packages/pyright-internal/src/tests/samples/typeForm4.py b/packages/pyright-internal/src/tests/samples/typeForm4.py
@@ -48,7 +48,7 @@ def func1():
 
     t10: TypeForm = TA2[str]
     t11: TypeForm[TA2[str]] = TA2[str]
-    t12: TypeForm[list[Any]] = TA2[str]
+    t12: TypeForm[list[Any] | str] = TA2[str]
 
     t13: TypeForm = TA2