Fixed a false positive "incompatible method override" error in a case…

… that involves both class-scoped and method-scoped type variables. This addresses #9347. (#9348)
microsoft · Oct 29, 2024 · 84b77b0 · 84b77b0
1 parent 2ffc5f1
commit 84b77b0
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Showing 4 changed files with 114 additions and 180 deletions.
diff --git a/packages/pyright-internal/src/analyzer/checker.ts b/packages/pyright-internal/src/analyzer/checker.ts
@@ -6558,9 +6558,11 @@ export class Checker extends ParseTreeWalker {
         }
 
         const baseClass = baseClassAndSymbol.classType;
-        const childClassSelf = ClassType.cloneAsInstance(selfSpecializeClass(childClassType));
+        const childClassSelf = ClassType.cloneAsInstance(
+            selfSpecializeClass(childClassType, { useBoundTypeVars: true })
+        );
 
-        let baseType = partiallySpecializeType(
+        const baseType = partiallySpecializeType(
             this._evaluator.getEffectiveTypeOfSymbol(baseClassAndSymbol.symbol),
             baseClass,
             this._evaluator.getTypeClassType(),
@@ -6575,7 +6577,6 @@ export class Checker extends ParseTreeWalker {
         );
 
         if (childClassType.shared.typeVarScopeId) {
-            baseType = makeTypeVarsBound(baseType, [childClassType.shared.typeVarScopeId]);
             overrideType = makeTypeVarsBound(overrideType, [childClassType.shared.typeVarScopeId]);
         }
 

diff --git a/packages/pyright-internal/src/analyzer/typeEvaluator.ts b/packages/pyright-internal/src/analyzer/typeEvaluator.ts
@@ -26812,6 +26812,7 @@ export function createTypeEvaluator(
     ): boolean {
         const baseParamDetails = getParamListDetails(baseMethod);
         const overrideParamDetails = getParamListDetails(overrideMethod);
+        const constraints = new ConstraintTracker();
 
         let canOverride = true;
 
@@ -26853,8 +26854,8 @@ export function createTypeEvaluator(
                                 overrideArgsType,
                                 baseParamDetails.params[i].type,
                                 diag?.createAddendum(),
-                                /* constraints */ undefined,
-                                AssignTypeFlags.Default
+                                constraints,
+                                AssignTypeFlags.Contravariant
                             )
                         ) {
                             LocAddendum.overrideParamType().format({
@@ -26976,8 +26977,8 @@ export function createTypeEvaluator(
                                 overrideParamType,
                                 baseParamType,
                                 diag?.createAddendum(),
-                                /* constraints */ undefined,
-                                AssignTypeFlags.Default
+                                constraints,
+                                AssignTypeFlags.Contravariant
                             )
                         ) {
                             diag?.addMessage(
@@ -27038,8 +27039,8 @@ export function createTypeEvaluator(
                             overrideParamType,
                             baseParamType,
                             diag?.createAddendum(),
-                            /* constraints */ undefined,
-                            AssignTypeFlags.Default
+                            constraints,
+                            AssignTypeFlags.Contravariant
                         )
                     ) {
                         diag?.addMessage(
@@ -27083,8 +27084,8 @@ export function createTypeEvaluator(
                             targetParamType,
                             paramInfo.type,
                             diag?.createAddendum(),
-                            /* constraints */ undefined,
-                            AssignTypeFlags.Default
+                            constraints,
+                            AssignTypeFlags.Contravariant
                         )
                     ) {
                         diag?.addMessage(
@@ -27164,7 +27165,7 @@ export function createTypeEvaluator(
                 baseReturnType,
                 overrideReturnType,
                 diag?.createAddendum(),
-                /* constraints */ undefined,
+                constraints,
                 AssignTypeFlags.Default
             )
         ) {