Elements. Add more type specific extensions.

Change-Id: Ia69931e1777111f2b2396e89c552317e51e6b809
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/396701
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Phil Quitslund <[email protected]>

Author: scheglov

pkg/analysis_server/lib/src/services/completion/dart/completion_manager.dart

@@ -403,9 +403,8 @@ class DartCompletionRequest {
     return analysisSession.inheritanceManager;
   }
 
-  /// Getter for the [Element2] repersentation of [libraryElement].
-  LibraryElement2 get libraryElement2 =>
-      libraryElement.asElement2 as LibraryElement2;
+  /// Getter for the [Element2] representation of [libraryElement].
+  LibraryElement2 get libraryElement2 => libraryElement.asElement2;
 
   /// Answer the [DartType] for Object in dart:core
   InterfaceType get objectType => libraryElement.typeProvider.objectType;

pkg/analysis_server/lib/src/services/completion/dart/declaration_helper.dart

@@ -339,7 +339,7 @@ class DeclarationHelper {
       if (matcherScore != -1) {
         collector.addSuggestion(
           ImportPrefixSuggestion(
-            libraryElement: importedLibrary.asElement2 as LibraryElement2,
+            libraryElement: importedLibrary.asElement2,
             prefixElement: prefixElement.asElement2,
             matcherScore: matcherScore,
           ),
@@ -902,17 +902,17 @@ class DeclarationHelper {
       var suggestion = switch (element) {
         ClassElement() => ClassSuggestion(
           importData: null,
-          element: element.asElement2 as ClassElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         ),
         EnumElement() => EnumSuggestion(
           importData: null,
-          element: element.asElement2 as EnumElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         ),
         ExtensionElement() => ExtensionSuggestion(
           importData: null,
-          element: element.asElement2 as ExtensionElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         ),
         ExtensionTypeElement() => ExtensionTypeSuggestion(
@@ -928,7 +928,7 @@ class DeclarationHelper {
         ),
         MixinElement() => MixinSuggestion(
           importData: null,
-          element: element.asElement2 as MixinElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         ),
         PropertyAccessorElement() => _createSuggestionFromTopLevelProperty(
@@ -937,7 +937,7 @@ class DeclarationHelper {
         ),
         TopLevelVariableElement() => TopLevelVariableSuggestion(
           importData: null,
-          element: element.asElement2 as TopLevelVariableElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         ),
         TypeAliasElement() => TypeAliasSuggestion(
@@ -1498,7 +1498,7 @@ class DeclarationHelper {
         if (variable is TopLevelVariableElement) {
           return TopLevelVariableSuggestion(
             importData: importData,
-            element: variable.asElement2 as TopLevelVariableElement2,
+            element: variable.asElement2,
             matcherScore: matcherScore,
           );
         }
@@ -1559,7 +1559,7 @@ class DeclarationHelper {
         if (matcherScore != -1) {
           var suggestion = ClassSuggestion(
             importData: importData,
-            element: element.asElement2 as ClassElement2,
+            element: element.asElement2,
             matcherScore: matcherScore,
           );
           collector.addSuggestion(suggestion);
@@ -1667,7 +1667,7 @@ class DeclarationHelper {
       if (matcherScore != -1) {
         var suggestion = EnumSuggestion(
           importData: importData,
-          element: element.asElement2 as EnumElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         );
         collector.addSuggestion(suggestion);
@@ -1696,7 +1696,7 @@ class DeclarationHelper {
       if (matcherScore != -1) {
         var suggestion = ExtensionSuggestion(
           importData: importData,
-          element: element.asElement2 as ExtensionElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         );
         collector.addSuggestion(suggestion);
@@ -1857,7 +1857,7 @@ class DeclarationHelper {
       if (matcherScore != -1) {
         var suggestion = MixinSuggestion(
           importData: importData,
-          element: element.asElement2 as MixinElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         );
         collector.addSuggestion(suggestion);
@@ -1878,7 +1878,7 @@ class DeclarationHelper {
       var matcherScore = state.matcher.score(element.displayName);
       if (matcherScore != -1) {
         var suggestion = FormalParameterSuggestion(
-          element: element.asElement2 as FormalParameterElement,
+          element: element.asElement2,
           distance: _variableDistance++,
           matcherScore: matcherScore,
         );
@@ -2054,7 +2054,7 @@ class DeclarationHelper {
     if (matcherScore != -1) {
       collector.addSuggestion(
         SuperParameterSuggestion(
-          element: element.asElement2 as FormalParameterElement,
+          element: element.asElement2,
           matcherScore: matcherScore,
         ),
       );
@@ -2132,7 +2132,7 @@ class DeclarationHelper {
       if (matcherScore != -1) {
         var suggestion = TopLevelVariableSuggestion(
           importData: importData,
-          element: element.asElement2 as TopLevelVariableElement2,
+          element: element.asElement2,
           matcherScore: matcherScore,
         );
         collector.addSuggestion(suggestion);

pkg/analysis_server/lib/src/services/completion/dart/in_scope_completion_pass.dart

@@ -23,7 +23,6 @@ import 'package:analyzer/dart/ast/syntactic_entity.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/source/source_range.dart';
 import 'package:analyzer/src/dart/ast/ast.dart';
@@ -380,7 +379,7 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
             var isWidget = isFlutterWidgetParameter(parameter);
             collector.addSuggestion(
               NamedArgumentSuggestion(
-                parameter: parameter.asElement2 as FormalParameterElement,
+                parameter: parameter.asElement2,
                 appendColon: true,
                 appendComma: appendComma,
                 replacementLength: replacementLength,
@@ -2022,7 +2021,7 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
                     collector.addSuggestion(
                       NamedArgumentSuggestion(
                         parameter:
-                            parameter.asElement2 as FormalParameterElement,
+                            parameter.asElement2,
                         matcherScore: matcherScore,
                         appendColon: appendColon,
                         appendComma: false,

pkg/analysis_server/lib/src/services/search/hierarchy.dart

@@ -306,7 +306,7 @@ Future<List<FormalParameterElement>> getHierarchyNamedParameters2(
     searchEngine,
     element.asElement as ParameterElement,
   );
-  return result.map((e) => e.asElement2 as FormalParameterElement).toList();
+  return result.map((e) => e.asElement2).toList();
 }
 
 /// Returns non-synthetic members of the given [InterfaceElement] and its super

pkg/analysis_server/lib/src/services/search/search_engine_internal.dart

@@ -292,8 +292,7 @@ class SearchMatchImpl implements SearchMatch {
   Element2 get element2 => element.asElement2!;
 
   @override
-  LibraryElement2 get libraryElement2 =>
-      libraryElement.asElement2 as LibraryElement2;
+  LibraryElement2 get libraryElement2 => libraryElement.asElement2;
 
   @override
   String toString() {

pkg/analysis_server/test/abstract_single_unit.dart

@@ -32,8 +32,7 @@ class AbstractSingleUnitTest extends AbstractContextTest {
   late FindElement findElement;
   late FindElement2 findElement2;
 
-  LibraryElement2 get testLibraryElement2 =>
-      testLibraryElement.asElement2 as LibraryElement2;
+  LibraryElement2 get testLibraryElement2 => testLibraryElement.asElement2;
 
   void addTestSource(String code) {
     testCode = code;

pkg/analyzer/lib/src/dart/ast/ast.dart

@@ -454,7 +454,7 @@ final class ArgumentListImpl extends AstNodeImpl implements ArgumentList {
 
   List<FormalParameterElement?>? get correspondingStaticParameters2 =>
       _correspondingStaticParameters
-          ?.map((parameter) => parameter.asElement2 as FormalParameterElement)
+          ?.map((parameter) => parameter?.asElement2)
           .toList();
 
   @override

pkg/analyzer/lib/src/dart/element/element.dart

@@ -6232,7 +6232,7 @@ abstract class InterfaceElementImpl2 extends InstanceElementImpl2
 
   @override
   ConstructorElement2? get unnamedConstructor2 =>
-      unnamedConstructor.asElement2 as ConstructorElement2;
+      unnamedConstructor?.asElement2;
 
   @override
   ConstructorElement? getNamedConstructor(String name) {
@@ -9903,20 +9903,12 @@ class SuperFormalParameterElementImpl2 extends FormalParameterElementImpl
   SuperFormalParameterElementImpl2(super.firstFragment);
 
   @override
-  SuperFormalParameterFragment get firstFragment =>
-      super.firstFragment as SuperFormalParameterFragment;
+  SuperFormalParameterElementImpl get firstFragment =>
+      super.firstFragment as SuperFormalParameterElementImpl;
 
   @override
   FormalParameterElement? get superConstructorParameter2 {
-    var superConstructorParameter =
-        (firstFragment as SuperFormalParameterElementImpl)
-            .superConstructorParameter;
-    return switch (superConstructorParameter) {
-      ParameterMember() =>
-        superConstructorParameter.asElement2 as FormalParameterElement?,
-      FormalParameterFragment()? => superConstructorParameter.element,
-      _ => null,
-    };
+    return firstFragment.superConstructorParameter?.asElement2;
   }
 }
 

pkg/analyzer/lib/src/dart/element/member.dart

@@ -111,8 +111,7 @@ class ConstructorMember extends ExecutableMember
   }
 
   @override
-  ConstructorElement2? get superConstructor2 =>
-      superConstructor.asElement2 as ConstructorElement2;
+  ConstructorElement2? get superConstructor2 => superConstructor?.asElement2;
 
   @override
   ConstructorElement2 get _element2 => declaration.asElement2;
@@ -224,10 +223,8 @@ abstract class ExecutableMember extends Member
   Element2? get enclosingElement2 => _element2.enclosingElement2;
 
   @override
-  List<FormalParameterElement> get formalParameters => parameters
-      .map((fragment) => fragment.asElement2 as FormalParameterElement?)
-      .nonNulls
-      .toList();
+  List<FormalParameterElement> get formalParameters =>
+      parameters.map((fragment) => fragment.asElement2).toList();
 
   @override
   bool get hasImplicitReturnType => declaration.hasImplicitReturnType;
@@ -1174,8 +1171,7 @@ class ParameterMember extends VariableMember
   @override
   List<TypeParameterElement2> get typeParameters2 => _element2.typeParameters2;
 
-  FormalParameterElement get _element2 =>
-      declaration.asElement2 as FormalParameterElement;
+  FormalParameterElement get _element2 => declaration.asElement2;
 
   @override
   T? accept<T>(ElementVisitor<T> visitor) =>