linter: Move 'overriddenMember' off of InheritanceManager3

This was an extension method on InheritanceManager3. But that class
may be disappearing in favor of methods on InterfaceElement. So this
change keeps the method as an extension method, but takes
InheritanceManager3 out of the picture.

Change-Id: I79147f7c39e0e7d94f0e65231e36a2baf2f54362
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/428162
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: srawlins

pkg/linter/lib/src/extensions.dart

@@ -352,6 +352,27 @@ extension ElementExtension on Element? {
         self.name3 == 'print' &&
         self.firstFragment.libraryFragment.element.isDartCore;
   }
+
+  /// Returns the class member that is overridden by `this`, if there is one,
+  /// as defined by [InterfaceElement.getInheritedMember].
+  ExecutableElement? get overriddenMember {
+    var member = switch (this) {
+      FieldElement(:var getter2) => getter2,
+      MethodElement method => method,
+      PropertyAccessorElement accessor => accessor,
+      _ => null,
+    };
+
+    if (member == null) return null;
+
+    var interfaceElement = member.enclosingElement2;
+    if (interfaceElement is! InterfaceElement) return null;
+
+    var name = Name.forElement(member);
+    if (name == null) return null;
+
+    return interfaceElement.getInheritedMember(name);
+  }
 }
 
 extension ExpressionExtension on Expression {
@@ -514,29 +535,6 @@ extension FunctionBodyExtension on FunctionBody? {
   }
 }
 
-extension InhertanceManager3Extension on InheritanceManager3 {
-  /// Returns the class member that is overridden by [member], if there is one,
-  /// as defined by [getInherited].
-  ExecutableElement? overriddenMember(Element? member) {
-    var executable = switch (member) {
-      FieldElement() => member.getter2,
-      MethodElement() => member,
-      PropertyAccessorElement() => member,
-      _ => null,
-    };
-
-    if (executable == null) return null;
-
-    var interfaceElement = executable.enclosingElement2;
-    if (interfaceElement is! InterfaceElement) return null;
-
-    var nameObj = Name.forElement(executable);
-    if (nameObj == null) return null;
-
-    return getInherited3(interfaceElement.thisType, nameObj);
-  }
-}
-
 extension InstanceElementExtension on InstanceElement {
   bool get isReflectiveTest =>
       this is ClassElement &&

pkg/linter/lib/src/rules/annotate_overrides.dart

@@ -40,7 +40,7 @@ class _Visitor extends SimpleAstVisitor<void> {
     if (element == null) return;
     if (element case Annotatable a when a.metadata2.hasOverride) return;
 
-    var member = context.inheritanceManager.overriddenMember(element);
+    var member = element.overriddenMember;
     if (member != null) {
       rule.reportAtToken(target, arguments: [member.name3!]);
     }

pkg/linter/lib/src/rules/prefer_void_to_null.dart

@@ -44,9 +44,7 @@ class _Visitor extends SimpleAstVisitor<void> {
     // Make sure we're checking a return type.
     if (parent.returnType?.offset != node.offset) return false;
 
-    var member = context.inheritanceManager.overriddenMember(
-      parent.declaredFragment?.element,
-    );
+    var member = parent.declaredFragment?.element.overriddenMember;
     if (member == null) return false;
 
     var returnType = member.returnType;

pkg/linter/lib/src/rules/public_member_api_docs.dart

@@ -110,10 +110,7 @@ class _Visitor extends SimpleAstVisitor<void> {
 
   /// Whether [node] overrides some other member.
   bool isOverridingMember(Declaration node) =>
-      context.inheritanceManager.overriddenMember(
-        node.declaredFragment?.element,
-      ) !=
-      null;
+      node.declaredFragment?.element.overriddenMember != null;
 
   @override
   void visitClassDeclaration(ClassDeclaration node) {

pkg/linter/lib/src/rules/strict_top_level_inference.dart

@@ -103,19 +103,17 @@ class _Visitor extends SimpleAstVisitor<void> {
 
     if (node.variables.length == 1) {
       var variable = node.variables.single;
-      var overriddenMember = context.inheritanceManager.overriddenMember(
-        variable.declaredFragment?.element,
-      );
+      var overriddenMember =
+          variable.declaredFragment?.element.overriddenMember;
       if (overriddenMember == null) {
         _report(variable.name, keyword: node.keyword);
       }
     } else {
       // Handle the multiple-variable case separately so that we can instead
       // report `LinterLintCode.strict_top_level_inference_split_to_types`.
       for (var variable in variablesMissingAnInitializer) {
-        var overriddenMember = context.inheritanceManager.overriddenMember(
-          variable.declaredFragment?.element,
-        );
+        var overriddenMember =
+            variable.declaredFragment?.element.overriddenMember;
         if (overriddenMember == null) {
           rule.reportAtToken(
             variable.name,
@@ -208,9 +206,7 @@ class _Visitor extends SimpleAstVisitor<void> {
         _checkFormalParameters(parameters.parameters);
       }
     } else {
-      var overriddenMember = context.inheritanceManager.overriddenMember(
-        node.declaredFragment?.element,
-      );
+      var overriddenMember = node.declaredFragment?.element.overriddenMember;
       if (overriddenMember == null &&
           node.returnType == null &&
           (!container.isReflectiveTest ||
@@ -246,9 +242,7 @@ class _Visitor extends SimpleAstVisitor<void> {
     if (node.isStatic) return false;
     if (container is ExtensionElement) return false;
     if (container is ExtensionTypeElement) return false;
-    var overriddenMember = context.inheritanceManager.overriddenMember(
-      node.declaredFragment?.element,
-    );
+    var overriddenMember = node.declaredFragment?.element.overriddenMember;
     return overriddenMember != null;
   }