Extension type. Issue 53920. Report conflict with inherited setter, even when there is getter.

Bug: #53920
Change-Id: Ib2d7715a45b4696ce56c200cbbadc60ee8ab3b81
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/334640
Reviewed-by: Samuel Rawlins <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/generated/error_verifier.dart

@@ -2009,31 +2009,55 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
     for (MethodElement method in enclosingClass.methods) {
       String name = method.name;
 
-      // find inherited property accessor
-      var inherited = _inheritanceManager.getInherited2(
+      // find inherited property accessors
+      final getter = _inheritanceManager.getInherited2(
           enclosingClass, Name(libraryUri, name));
-      inherited ??= _inheritanceManager.getInherited2(
+      final setter = _inheritanceManager.getInherited2(
           enclosingClass, Name(libraryUri, '$name='));
 
-      if (method.isStatic && inherited != null) {
-        errorReporter.reportErrorForElement(
-            CompileTimeErrorCode.CONFLICTING_STATIC_AND_INSTANCE, method, [
-          enclosingClass.displayName,
-          name,
-          inherited.enclosingElement.displayName,
-        ]);
-      } else if (inherited is PropertyAccessorElement) {
-        // Extension type methods redeclare getters with the same name.
-        if (enclosingClass is ExtensionTypeElement && inherited.isGetter) {
+      if (method.isStatic) {
+        void reportStaticConflict(ExecutableElement inherited) {
+          errorReporter.reportErrorForElement(
+              CompileTimeErrorCode.CONFLICTING_STATIC_AND_INSTANCE, method, [
+            enclosingClass.displayName,
+            name,
+            inherited.enclosingElement.displayName,
+          ]);
+        }
+
+        if (getter != null) {
+          reportStaticConflict(getter);
           continue;
         }
+
+        if (setter != null) {
+          reportStaticConflict(setter);
+          continue;
+        }
+      }
+
+      void reportFieldConflict(PropertyAccessorElement inherited) {
         errorReporter.reportErrorForElement(
             CompileTimeErrorCode.CONFLICTING_METHOD_AND_FIELD, method, [
           enclosingClass.displayName,
           name,
           inherited.enclosingElement.displayName
         ]);
       }
+
+      if (getter is PropertyAccessorElement) {
+        if (enclosingClass is ExtensionTypeElement) {
+          // Extension type methods redeclare getters with the same name.
+        } else {
+          reportFieldConflict(getter);
+          continue;
+        }
+      }
+
+      if (setter is PropertyAccessorElement) {
+        reportFieldConflict(setter);
+        continue;
+      }
     }
 
     // getter declared in the enclosing class vs. inherited method

pkg/analyzer/test/src/diagnostics/conflicting_method_and_field_test.dart

@@ -84,6 +84,20 @@ enum E with M {
     ]);
   }
 
+  test_extensionType_field_external() async {
+    await assertErrorsInCode(r'''
+extension type A(int it) {
+  external int foo;
+}
+
+extension type B(int it) implements A {
+  void foo() {}
+}
+''', [
+      error(CompileTimeErrorCode.CONFLICTING_METHOD_AND_FIELD, 97, 3),
+    ]);
+  }
+
   test_extensionType_getter() async {
     await assertNoErrorsInCode(r'''
 extension type A(int it) {