Add InterfaceType.asInstanceOf(ClassElement) to API.

[email protected]

Change-Id: I91c61aea37bb4ccfb300083e1b017b8e71ef6d6d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153703
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analysis_server/lib/src/services/correction/dart/replace_with_var.dart

@@ -6,7 +6,7 @@ import 'package:analysis_server/src/services/correction/assist.dart';
 import 'package:analysis_server/src/services/correction/dart/abstract_producer.dart';
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/src/dart/element/type.dart';
+import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer_plugin/utilities/assist/assist.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
@@ -127,7 +127,7 @@ class ReplaceWithVar extends CorrectionProducer {
           return false;
         }
         final iterableType = parent.iterable.staticType;
-        if (iterableType is InterfaceTypeImpl) {
+        if (iterableType is InterfaceType) {
           var instantiatedType =
               iterableType.asInstanceOf(typeProvider.iterableElement);
           if (instantiatedType?.typeArguments?.first == staticType) {

pkg/analyzer/CHANGELOG.md

@@ -3,6 +3,7 @@
 * Added `DynamicType`, `NeverType`, and `VoidType` interfaces.
 * Added `TypeVisitor` and `DartType.accept(TypeVisitor)`.
 * Changed `ConstructorElement.returnType` to `InterfaceType`.
+* Added `InterfaceType.asInstanceOf(ClassElement)`.
 
 ## 0.39.12
 * Deprecated `canUseSummaries` in `DartSdkManager` constructor.

pkg/analyzer/lib/dart/element/type.dart

@@ -295,6 +295,20 @@ abstract class InterfaceType implements ParameterizedType {
   /// represent a mixin declaration.
   List<InterfaceType> get superclassConstraints;
 
+  /// Return the canonical interface that this type implements for [element],
+  /// or `null` if such an interface does not exist.
+  ///
+  /// For example, given the following definitions
+  /// ```
+  /// class A<E> {}
+  /// class B<E> implements A<E> {}
+  /// class C implements A<String> {}
+  /// ```
+  /// Asking the type `B<int>` for the type associated with `A` will return the
+  /// type `A<int>`. Asking the type `C` for the type associated with `A` will
+  /// return the type `A<String>`.
+  InterfaceType asInstanceOf(ClassElement element);
+
   /// Return the element representing the getter with the given [name] that is
   /// declared in this class, or `null` if this class does not declare a getter
   /// with the given name.

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

@@ -894,20 +894,7 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
     builder.writeInterfaceType(this);
   }
 
-  /// Return either this type or a supertype of this type that is defined by the
-  /// [targetElement], or `null` if such a type does not exist. If this type
-  /// inherits from the target element along multiple paths, then the returned
-  /// type is arbitrary.
-  ///
-  /// For example, given the following definitions
-  /// ```
-  /// class A<E> {}
-  /// class B<E> implements A<E> {}
-  /// class C implements A<String> {}
-  /// ```
-  /// Asking the type `B<int>` for the type associated with `A` will return the
-  /// type `A<int>`. Asking the type `C` for the type associated with `A` will
-  /// return the type `A<String>`.
+  @override
   InterfaceType asInstanceOf(ClassElement targetElement) {
     if (element == targetElement) {
       return this;

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

@@ -273,7 +273,7 @@ abstract class TypeSystem implements public.TypeSystem {
     if (type is! InterfaceType) return null;
     if (genericType is! InterfaceType) return null;
 
-    var asInstanceOf = (type as InterfaceTypeImpl)
+    var asInstanceOf = (type as InterfaceType)
         .asInstanceOf((genericType as InterfaceType).element);
 
     if (asInstanceOf != null) {

pkg/analyzer/lib/src/dart/resolver/body_inference_context.dart

@@ -138,7 +138,7 @@ class BodyInferenceContext {
   }
 
   static DartType _argumentOf(DartType type, ClassElement element) {
-    if (type is InterfaceTypeImpl) {
+    if (type is InterfaceType) {
       var elementType = type.asInstanceOf(element);
       if (elementType != null) {
         return elementType.typeArguments[0];

pkg/analyzer/lib/src/dart/resolver/for_resolver.dart

@@ -58,7 +58,7 @@ class ForResolver {
         ? _resolver.typeProvider.streamElement
         : _resolver.typeProvider.iterableElement;
 
-    InterfaceType iteratedType = iterableType is InterfaceTypeImpl
+    InterfaceType iteratedType = iterableType is InterfaceType
         ? iterableType.asInstanceOf(iteratedElement)
         : null;
 

pkg/analyzer/lib/src/dart/resolver/typed_literal_resolver.dart

@@ -178,7 +178,7 @@ class TypedLiteralResolver {
       var expressionType = element.expression.staticType;
       if (expressionType.isDynamic) {
         return expressionType;
-      } else if (expressionType is InterfaceTypeImpl) {
+      } else if (expressionType is InterfaceType) {
         if (expressionType.isDartCoreNull) {
           if (element.isNullAware) {
             return expressionType;
@@ -336,16 +336,16 @@ class TypedLiteralResolver {
       if (!isNull && expressionType is InterfaceType) {
         if (_typeSystem.isSubtypeOf2(
             expressionType, _typeProvider.iterableForSetMapDisambiguation)) {
-          InterfaceType iterableType = (expressionType as InterfaceTypeImpl)
-              .asInstanceOf(_typeProvider.iterableElement);
+          InterfaceType iterableType =
+              expressionType.asInstanceOf(_typeProvider.iterableElement);
           return _InferredCollectionElementTypeInformation(
               elementType: iterableType.typeArguments[0],
               keyType: null,
               valueType: null);
         } else if (_typeSystem.isSubtypeOf2(
             expressionType, _typeProvider.mapForSetMapDisambiguation)) {
-          InterfaceType mapType = (expressionType as InterfaceTypeImpl)
-              .asInstanceOf(_typeProvider.mapElement);
+          InterfaceType mapType =
+              expressionType.asInstanceOf(_typeProvider.mapElement);
           List<DartType> typeArguments = mapType.typeArguments;
           return _InferredCollectionElementTypeInformation(
               elementType: null,

pkg/analyzer/lib/src/error/literal_element_verifier.dart

@@ -7,7 +7,6 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_provider.dart';
 import 'package:analyzer/error/listener.dart';
-import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/type_system.dart';
 import 'package:analyzer/src/error/codes.dart';
 
@@ -145,7 +144,7 @@ class LiteralElementVerifier {
     expressionType = typeSystem.resolveToBound(expressionType);
 
     InterfaceType iterableType;
-    if (expressionType is InterfaceTypeImpl) {
+    if (expressionType is InterfaceType) {
       iterableType = expressionType.asInstanceOf(typeProvider.iterableElement);
     }
 
@@ -188,7 +187,7 @@ class LiteralElementVerifier {
     expressionType = typeSystem.resolveToBound(expressionType);
 
     InterfaceType mapType;
-    if (expressionType is InterfaceTypeImpl) {
+    if (expressionType is InterfaceType) {
       mapType = expressionType.asInstanceOf(typeProvider.mapElement);
     }
 

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

@@ -2228,7 +2228,7 @@ class ErrorVerifier extends RecursiveAstVisitor<void> {
     }
 
     DartType sequenceElementType;
-    if (iterableType is InterfaceTypeImpl) {
+    if (iterableType is InterfaceType) {
       var sequenceElement = awaitKeyword != null
           ? _typeProvider.streamElement
           : _typeProvider.iterableElement;

pkg/analyzer/lib/src/task/strong/checker.dart

@@ -174,7 +174,7 @@ class CodeChecker extends RecursiveAstVisitor {
       checkAssignment(element.expression, expressionCastType);
 
       var exprType = element.expression.staticType;
-      var asIterableType = exprType is InterfaceTypeImpl
+      var asIterableType = exprType is InterfaceType
           ? exprType.asInstanceOf(typeProvider.iterableElement)
           : null;
       var elementType =
@@ -213,7 +213,7 @@ class CodeChecker extends RecursiveAstVisitor {
       checkAssignment(element.expression, expressionCastType);
 
       var exprType = element.expression.staticType;
-      var asMapType = exprType is InterfaceTypeImpl
+      var asMapType = exprType is InterfaceType
           ? exprType.asInstanceOf(typeProvider.mapElement)
           : null;
 
@@ -845,7 +845,7 @@ class CodeChecker extends RecursiveAstVisitor {
 
   DartType _getInstanceTypeArgument(
       DartType expressionType, ClassElement instanceType) {
-    if (expressionType is InterfaceTypeImpl) {
+    if (expressionType is InterfaceType) {
       var asInstanceType = expressionType.asInstanceOf(instanceType);
       if (asInstanceType != null) {
         return asInstanceType.typeArguments[0];