Added test case for microsoft#5027.

packages/pyright-internal/src/tests/samples/protocol42.py

@@ -0,0 +1,21 @@
+# This sample tests the case where a protocol implementation uses a
+# method-scoped type variable.
+
+from typing import Protocol, Sequence, TypeVar
+
+Input = TypeVar("Input", contravariant=True)
+Output = TypeVar("Output", covariant=True)
+T = TypeVar("T")
+
+
+class ProtoA(Protocol[Input, Output]):
+    def __call__(self, input: Input) -> Output:
+        raise NotImplementedError
+
+
+class ImplA:
+    def __call__(self, input: Sequence[T]) -> T:
+        return input[0]
+
+
+v1: ProtoA[Sequence[int], int] = ImplA()

packages/pyright-internal/src/tests/typeEvaluator2.test.ts

@@ -1377,6 +1377,12 @@ test('Protocol41', () => {
     TestUtils.validateResults(analysisResults, 0);
 });
 
+test('Protocol42', () => {
+    const analysisResults = TestUtils.typeAnalyzeSampleFiles(['protocol42.py']);
+
+    TestUtils.validateResults(analysisResults, 0);
+});
+
 test('TypedDict1', () => {
     const analysisResults = TestUtils.typeAnalyzeSampleFiles(['typedDict1.py']);