Fixed bug that causes Final annotation not to be honored when wrapped in an Annotated annotation. This addresses #8097.

packages/pyright-internal/src/analyzer/binder.ts

@@ -3924,6 +3924,12 @@ export class Binder extends ParseTreeWalker {
 
             if (this._isTypingAnnotation(typeAnnotation, 'Final')) {
                 isFinal = true;
+            } else if (
+                typeAnnotation.nodeType === ParseNodeType.Index &&
+                typeAnnotation.items.length > 0 &&
+                this._isTypingAnnotation(typeAnnotation.baseExpression, 'Annotated')
+            ) {
+                return this._isAnnotationFinal(typeAnnotation.items[0].valueExpression);
             } else if (typeAnnotation.nodeType === ParseNodeType.Index && typeAnnotation.items.length === 1) {
                 // Recursively call to see if the base expression is "Final".
                 const finalInfo = this._isAnnotationFinal(typeAnnotation.baseExpression);

packages/pyright-internal/src/tests/samples/final3.py

@@ -2,37 +2,37 @@
 # introduced in Python 3.8.
 
 import typing
-from typing import Any, Final, Protocol, TypeVar
+from typing import Annotated, Any, Final, Protocol, TypeVar
 
 T = TypeVar("T")
 
-foo1: typing.Final = 3
+v1: typing.Final = 3
 
-must_be_int: int = foo1
+must_be_int: int = v1
 
 # This should generate an error because
 # reassignment of a Final variable should
 # not be allowed.
-foo1 = 4
+v1 = 4
 
 # This should generate an error because there
 # is a previous Final declaration.
-foo1: Final[int]
+v1: Final[int]
 
 # This should generate an error because
 # the type doesn't match.
-foo2: Final[str] = 3
+v2: Final[str] = 3
 
 # This should generate an error because
 # we expect only one type argument for Final.
-foo3: Final[str, int] = "hello"
+v3: Final[str, int] = "hello"
 
 
-foo4: Final = 5
-reveal_type(foo4, expected_text="Literal[5]")
+v4: Final = 5
+reveal_type(v4, expected_text="Literal[5]")
 
 
-class Foo:
+class ClassA:
     member1: Final = 4
 
     # This should generate an error because only
@@ -85,11 +85,11 @@ class Foo:
         self.member7: Final = 6
 
 
-reveal_type(Foo.member1, expected_text="Literal[4]")
-reveal_type(Foo(True).member1, expected_text="Literal[4]")
+reveal_type(ClassA.member1, expected_text="Literal[4]")
+reveal_type(ClassA(True).member1, expected_text="Literal[4]")
 
 
-class Bar(Foo):
+class ClassB(ClassA):
     # This should generate an error because we are overriding
     # a member that is marked Final in the parent class.
     member1 = 5
@@ -118,7 +118,7 @@ def func1(a: Final[int]):
 b: list[Final[int]] = []
 
 
-class ClassA:
+class ClassC:
     member1: Final = 3
     member2: Final
     member4: Final
@@ -133,10 +133,10 @@ class ClassA:
         self.member3: Final = "hi"
 
         # This should generate an error.
-        ClassA.member4 = "hi"
+        ClassC.member4 = "hi"
 
         # This should generate an error.
-        ClassA.member5 = 3
+        ClassC.member5 = 3
 
     def other(self):
         # This should generate an error.
@@ -149,7 +149,7 @@ class ClassA:
         self.member3 = "hi"
 
 
-a = ClassA()
+a = ClassC()
 
 # This should generate an error.
 a.member1 = 4
@@ -185,7 +185,7 @@ def func2():
     (a, x) = (1, 2)
 
 
-class ClassB:
+class ClassD:
     def __init__(self):
         self.x: Final = 1
 
@@ -194,7 +194,7 @@ class ClassB:
         self.x += 1
 
 
-class ClassC(Protocol):
+class ClassE(Protocol):
     x: Final[int]
 
 
@@ -206,11 +206,11 @@ def func3(x: type[T]) -> T:
 func3(Final[int])
 
 
-foo5: Final = lambda: None
+v5: Final = lambda: None
 
 
 # This should generate an error because foo5 is declared as Final.
-def foo5() -> None:
+def v5() -> None:
     pass
 
 
@@ -218,3 +218,19 @@ def foo5() -> None:
 from typing import ClassVar
 
 ClassVar: Final = 3
+
+
+v6: Annotated[Final[int], "meta"] = 1
+
+# This should generate an error
+v6 = 2
+
+v7: Annotated[Annotated[Final[int], "meta"], "meta"] = 1
+
+# This should generate an error
+v7 = 2
+
+v8: Annotated[Final, "meta"] = 1
+
+# This should generate an error
+v8 = 2

packages/pyright-internal/src/tests/typeEvaluator4.test.ts

@@ -32,7 +32,7 @@ test('Final2', () => {
 
 test('Final3', () => {
     const analysisResults = TestUtils.typeAnalyzeSampleFiles(['final3.py']);
-    TestUtils.validateResults(analysisResults, 35);
+    TestUtils.validateResults(analysisResults, 38);
 });
 
 test('Final4', () => {