Changed type evaluation behavior for accesses to attributes on a clas…

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

@@ -21519,6 +21519,11 @@ export function createTypeEvaluator(importLookup: ImportLookup, evaluatorOptions
                     isIncomplete: !!typeResult.isIncomplete,
                 };
             }
+        } else if (isAnyOrUnknown(member.classType)) {
+            return {
+                type: member.classType,
+                isIncomplete: false,
+            };
         }
 
         return undefined;

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

@@ -180,7 +180,7 @@ export interface TypeResult<T extends Type = Type> {
 
     // Used for getTypeOfObjectMember to indicate that class
     // that declares the member.
-    classType?: ClassType | UnknownType;
+    classType?: ClassType | UnknownType | AnyType;
 
     // Variadic type arguments allow the shorthand "()" to
     // represent an empty tuple (i.e. Tuple[()]).
@@ -390,7 +390,7 @@ export interface ClassMemberLookup {
     isClassMember: boolean;
 
     // The class that declares the accessed member.
-    classType?: ClassType | UnknownType;
+    classType?: ClassType | UnknownType | AnyType;
 
     // True if the member is explicitly declared as ClassVar
     // within a Protocol.

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

@@ -71,7 +71,7 @@ export interface ClassMember {
     symbol: Symbol;
 
     // Partially-specialized class that contains the class member
-    classType: ClassType | UnknownType;
+    classType: ClassType | UnknownType | AnyType;
 
     // True if it is an instance or class member; it can be both a class and
     // an instance member in cases where a class variable is overridden
@@ -1483,11 +1483,11 @@ export function* getClassMemberIterator(
                     // The class derives from an unknown type, so all bets are off
                     // when trying to find a member. Return an unknown symbol.
                     const cm: ClassMember = {
-                        symbol: Symbol.createWithType(SymbolFlags.None, UnknownType.create()),
+                        symbol: Symbol.createWithType(SymbolFlags.None, mroClass),
                         isInstanceMember: false,
                         isClassMember: true,
                         isClassVar: false,
-                        classType: UnknownType.create(),
+                        classType: isAnyOrUnknown(mroClass) ? mroClass : UnknownType.create(),
                         isTypeDeclared: false,
                         skippedUndeclaredType: false,
                     };
@@ -1566,13 +1566,13 @@ export function* getClassMemberIterator(
         }
     } else if (isAnyOrUnknown(classType)) {
         // The class derives from an unknown type, so all bets are off
-        // when trying to find a member. Return an unknown symbol.
+        // when trying to find a member. Return an Any or Unknown symbol.
         const cm: ClassMember = {
-            symbol: Symbol.createWithType(SymbolFlags.None, UnknownType.create()),
+            symbol: Symbol.createWithType(SymbolFlags.None, classType),
             isInstanceMember: false,
             isClassMember: true,
             isClassVar: false,
-            classType: UnknownType.create(),
+            classType,
             isTypeDeclared: false,
             skippedUndeclaredType: false,
         };

packages/pyright-internal/src/tests/samples/memberAccess24.py

@@ -0,0 +1,20 @@
+# This sample tests the case where an attribute is accessed from a
+# class that derives from an unknown type or Any.
+
+from typing import Any
+from dummy import UnknownX  # type: ignore
+
+
+class DerivesFromUnknown(UnknownX):
+    pass
+
+
+class DerivesFromAny(Any):
+    pass
+
+
+v1 = DerivesFromUnknown().x
+reveal_type(v1, expected_text="Unknown")
+
+v2 = DerivesFromAny().x
+reveal_type(v2, expected_text="Any")

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

@@ -550,6 +550,11 @@ test('MemberAccess23', () => {
     TestUtils.validateResults(analysisResults, 0);
 });
 
+test('MemberAccess24', () => {
+    const analysisResults = TestUtils.typeAnalyzeSampleFiles(['memberAccess24.py']);
+    TestUtils.validateResults(analysisResults, 0);
+});
+
 test('DataClassNamedTuple1', () => {
     const analysisResults = TestUtils.typeAnalyzeSampleFiles(['dataclassNamedTuple1.py']);