Remove all references to MultiplyInheritedExecutableElement (#3914)

lib/src/model/inheriting_container.dart

@@ -604,7 +604,7 @@ abstract class InheritingContainer extends Container {
     var getter = containerAccessorFrom(getterElement);
     var setter = containerAccessorFrom(setterElement);
     // Rebind [getterElement], [setterElement] as [ModelElement.from] can
-    // resolve [MultiplyInheritedExecutableElement]s or resolve [Member]s.
+    // resolve [Member]s.
     getterElement = getter?.element;
     setterElement = setter?.element;
     assert(getter != null || setter != null);

lib/src/model/model_element.dart

@@ -197,7 +197,6 @@ abstract class ModelElement
     _cacheNewModelElement(e, newModelElement, library,
         enclosingContainer: enclosingContainer);
 
-    assert(newModelElement.element is! MultiplyInheritedExecutableElement);
     return newModelElement;
   }
 
@@ -255,7 +254,6 @@ abstract class ModelElement
     _cacheNewModelElement(e, newModelElement, library,
         enclosingContainer: enclosingContainer);
 
-    assert(newModelElement.element is! MultiplyInheritedExecutableElement);
     return newModelElement;
   }
 
@@ -288,8 +286,6 @@ abstract class ModelElement
     Member? originalMember,
   }) {
     return switch (e) {
-      MultiplyInheritedExecutableElement() => e.resolveMultiplyInheritedElement(
-          library, packageGraph, enclosingContainer as Class),
       LibraryElement() => packageGraph.findButDoNotCreateLibraryFor(e)!,
       PrefixElement() => Prefix(e, library, packageGraph),
       EnumElement() => Enum(e, library, packageGraph),
@@ -349,8 +345,7 @@ abstract class ModelElement
   }) {
     // Accessors can be part of a [Container], or a part of a [Library].
     if (e.enclosingElement3 is ExtensionElement ||
-        e.enclosingElement3 is InterfaceElement ||
-        e is MultiplyInheritedExecutableElement) {
+        e.enclosingElement3 is InterfaceElement) {
       if (enclosingContainer == null || enclosingContainer is Extension) {
         return ContainerAccessor(e, library, packageGraph, enclosingContainer);
       }
@@ -796,27 +791,3 @@ abstract class ModelElement
 
   String get linkedObjectType => _packageGraph.dartCoreObject;
 }
-
-extension on MultiplyInheritedExecutableElement {
-  /// Resolves this very rare case incorrectly by picking the closest element in
-  /// the inheritance and interface chains from the analyzer.
-  // TODO(jcollins-g): Implement resolution per ECMA-408 4th edition, page 39
-  // #22.
-  ModelElement resolveMultiplyInheritedElement(
-      Library library, PackageGraph packageGraph, Class enclosingClass) {
-    var inheritables = inheritedElements
-        .map((e) => ModelElement.forElement(e, packageGraph) as Inheritable);
-    late Inheritable foundInheritable;
-    var lowIndex = enclosingClass.inheritanceChain.length;
-    for (var inheritable in inheritables) {
-      var index = enclosingClass.inheritanceChain
-          .indexOf(inheritable.enclosingElement as InheritingContainer);
-      if (index < lowIndex) {
-        foundInheritable = inheritable;
-        lowIndex = index;
-      }
-    }
-    return ModelElement.for_(foundInheritable.element, library, packageGraph,
-        enclosingContainer: enclosingClass);
-  }
-}

test/end2end/model_test.dart

@@ -1068,39 +1068,6 @@ void main() async {
     });
   });
 
-  group('MultiplyInheritedExecutableElement handling', () {
-    late final Class BaseThingy, BaseThingy2, ImplementingThingy2;
-    late final Method aImplementingThingyMethod;
-    late final Field aImplementingThingyField;
-    late final Field aImplementingThingy;
-    late final Accessor aImplementingThingyAccessor;
-
-    setUpAll(() {
-      BaseThingy = fakeLibrary.classes.named('BaseThingy');
-      BaseThingy2 = fakeLibrary.classes.named('BaseThingy2');
-      ImplementingThingy2 = fakeLibrary.classes.named('ImplementingThingy2');
-
-      aImplementingThingy =
-          ImplementingThingy2.instanceFields.named('aImplementingThingy');
-      aImplementingThingyMethod = ImplementingThingy2.instanceMethods
-          .named('aImplementingThingyMethod');
-      aImplementingThingyField =
-          ImplementingThingy2.instanceFields.named('aImplementingThingyField');
-      aImplementingThingyAccessor = aImplementingThingyField.getter!;
-    });
-
-    test('Verify behavior of imperfect resolver', () {
-      expect(aImplementingThingy.element.enclosingElement3,
-          equals(BaseThingy2.element));
-      expect(aImplementingThingyMethod.element.enclosingElement3,
-          equals(BaseThingy.element));
-      expect(aImplementingThingyField.element.enclosingElement3,
-          equals(BaseThingy.element));
-      expect(aImplementingThingyAccessor.element.enclosingElement3,
-          equals(BaseThingy.element));
-    });
-  });
-
   group('Docs as HTML', () {
     late final Class Apple, B, superAwesomeClass, foo2;
     late final TopLevelVariable incorrectDocReferenceFromEx;

testing/test_package/lib/fake.dart

@@ -83,24 +83,6 @@ export 'src/reexport_this.dart';
 /// Does not render with emoji 3ffe:2a00:100:7031::1
 const int hasMarkdownInDoc = 1;
 
-abstract class ImplementingThingy implements BaseThingy {}
-
-abstract class BaseThingy {
-  // ignore: public_member_api_docs
-  ImplementingThingy get aImplementingThingy;
-  ImplementingThingy? aImplementingThingyField;
-  void aImplementingThingyMethod(ImplementingThingy parameter);
-}
-
-abstract class ImplementingThingy2 implements BaseThingy2, ImplementingThingy {}
-
-/// Test for MultiplyInheritedExecutableElement handling.
-abstract class BaseThingy2 implements BaseThingy {
-  /// BaseThingy2's doc for aImplementingThingy.
-  @override
-  ImplementingThingy2 get aImplementingThingy;
-}
-
 /// This function has a link to a renamed library class member.
 ///
 /// Link to library: [renamedLib]