Reduce strong mode errors and warnings

pkg/front_end/lib/src/fasta/analyzer/mock_element.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.analyzer.mock_element;
 
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/type.dart';
+import 'package:analyzer/dart/constant/value.dart';
+import 'package:analyzer/src/generated/source.dart' show
+     SourceRange;
 
 import '../errors.dart' show
     internalError;
 
 abstract class MockElement implements Element {
   final ElementKind kind;
 
   MockElement(this.kind);
 
   get librarySource => internalError("not supported.");
@@ skipping 35 matching lines @@
   get metadata => internalError("not supported.");
 
   String get name => internalError("not supported.");
 
   int get nameLength => internalError("not supported.");
 
   int get nameOffset => -1;
 
   get unit => internalError("not supported.");
 
-  accept(visitor) => internalError("not supported.");
+  T accept<T>(ElementVisitor<T> visitor) => internalError("not supported.");

[ahe, 2017/02/02 07:28:30]

The types added in this file should be inferred from supertypes.

[Siggi Cherem (dart-lang), 2017/02/02 16:30:35]

Agree - I was surprised that this wasn't working. I'll follow up to see why.

[Siggi Cherem (dart-lang), 2017/02/06 23:35:50]

Fixed. There were two issues:
 - some methods were declared in this class but not in `Element`, so there was
nothing to inherit in those cases, I moved those to the subclasses where they
are first needed and added an extra interface impementation to MockElement as
well.
 - arity of type-arguments had to match too. In this case I had to add <T>, but
I can still omit the types on the arguments and return value.

 
   String computeDocumentationComment() => internalError("not supported.");
 
-  computeNode() => internalError("not supported.");
+  AstNode computeNode() => internalError("not supported.");
 
-  Element getAncestor(predicate) => internalError("not supported.");
+  E getAncestor<E extends Element>(bool predicate(Element e))
+    => internalError("not supported.");
 
   String getExtendedDisplayName(String shortName) {
     return internalError("not supported.");
   }
 
   bool isAccessibleIn(LibraryElement library) {
     return internalError("not supported.");
   }
 
   void visitChildren(visitor) => internalError("not supported.");
 
   String get uri => internalError("not supported.");
 
   int get uriEnd => internalError("not supported.");
 
   int get uriOffset => internalError("not supported.");
 
-  get type => null;
+  DartType get type => null;
 
-  get typeParameters => internalError("not supported.");
+  List<TypeParameterElement> get typeParameters =>
+    internalError("not supported.");
 
   List<ParameterElement> get parameters => internalError("not supported.");
 
-  get returnType => internalError("not supported.");
+  DartType get returnType => internalError("not supported.");
 
   List<FunctionElement> get functions => internalError("not supported.");
 
   bool get hasImplicitReturnType => internalError("not supported.");
 
   bool get isAbstract => internalError("not supported.");
 
   bool get isAsynchronous => internalError("not supported.");
 
   bool get isExternal => internalError("not supported.");
 
   bool get isGenerator => internalError("not supported.");
 
   bool get isOperator => internalError("not supported.");
 
   bool get isStatic => internalError("not supported.");
 
   bool get isSynchronous => internalError("not supported.");
 
   List<LabelElement> get labels => internalError("not supported.");
 
   List<LocalVariableElement> get localVariables {
     return internalError("not supported.");
   }
 
-  get visibleRange => internalError("not supported.");
+  SourceRange get visibleRange => internalError("not supported.");
 
-  get constantValue => internalError("not supported.");
+  DartObject get constantValue => internalError("not supported.");
 
   bool get hasImplicitType => internalError("not supported.");
 
   FunctionElement get initializer => internalError("not supported.");
 
   bool get isConst => internalError("not supported.");
 
   bool get isFinal => internalError("not supported.");
 
   bool get isPotentiallyMutatedInClosure => internalError("not supported.");
 
   bool get isPotentiallyMutatedInScope => internalError("not supported.");
 
-  computeConstantValue() => internalError("not supported.");
+  DartObject computeConstantValue() => internalError("not supported.");
 }
 
 abstract class MockLibraryElement extends MockElement
     implements LibraryElement {
   MockLibraryElement()
       : super(ElementKind.LIBRARY);
 
   CompilationUnitElement get definingCompilationUnit {
     return internalError("not supported.");
   }
@@ skipping 49 matching lines @@
 
 abstract class MockCompilationUnitElement extends MockElement
     implements CompilationUnitElement {
   MockCompilationUnitElement()
       : super(ElementKind.COMPILATION_UNIT);
 
   List<PropertyAccessorElement> get accessors {
     return internalError("not supported.");
   }
 
+  LibraryElement get enclosingElement => internalError("not supported.");
+
   List<ClassElement> get enums => internalError("not supported.");
 
   List<FunctionElement> get functions => internalError("not supported.");
 
   List<FunctionTypeAliasElement> get functionTypeAliases {
     return internalError("not supported.");
   }
 
   bool get hasLoadLibraryFunction => internalError("not supported.");
 
   List<TopLevelVariableElement> get topLevelVariables {
     return internalError("not supported.");
   }
 
   List<ClassElement> get types => internalError("not supported.");
 
   Element getElementAt(int offset) => internalError("not supported.");
 
   ClassElement getEnum(String name) => internalError("not supported.");
 
   ClassElement getType(String name) => internalError("not supported.");
+
+  CompilationUnit computeNode() => internalError("not supported.");
 }
 
 abstract class MockClassElement extends MockElement implements ClassElement {
   MockClassElement()
       : super(ElementKind.CLASS);
 
   List<PropertyAccessorElement> get accessors {
     return internalError("not supported.");
   }
 
@@ skipping 82 matching lines @@
   }
 
   MethodElement lookUpMethod(String methodName, LibraryElement library) {
     return internalError("not supported.");
   }
 
   PropertyAccessorElement lookUpSetter(
       String setterName, LibraryElement library) {
     return internalError("not supported.");
   }
+
+  NamedCompilationUnitMember computeNode() => internalError("not supported.");
+
+  InterfaceType get type => internalError("not supported.");
 }
 
 abstract class MockFunctionElement extends MockElement
     implements FunctionElement {
   MockFunctionElement()
       : super(ElementKind.FUNCTION);
 
   bool get isEntryPoint => internalError("not supported.");
+
+  FunctionType get type => internalError("not supported.");
+
+  FunctionDeclaration computeNode() => internalError("not supported.");
 }
 
 abstract class MockParameterElement extends MockElement
     implements ParameterElement {
   MockParameterElement()
       : super(ElementKind.PARAMETER);
 
   String get defaultValueCode => internalError("not supported.");
 
   bool get isCovariant => internalError("not supported.");
 
   bool get isInitializingFormal => internalError("not supported.");
 
   get parameterKind => internalError("not supported.");
 
   List<ParameterElement> get parameters => internalError("not supported.");
 
-  List<TypeParameterElement> get typeParameters {
-    return internalError("not supported.");
-  }
-
   void appendToWithoutDelimiters(StringBuffer buffer) {
     return internalError("not supported.");
   }
+
+  FormalParameter computeNode() => internalError("not supported.");
 }