Build GenericFunctionTypeElementImpl in both ApiElementBuilder and LocalElementBuilder.

pkg/analyzer/test/dart/element/builder_test.dart

 // Copyright (c) 2014, 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 analyzer.test.dart.element.builder_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_ast_factory.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 1096 matching lines @@
     // Validate the variable element.
     var variableElement = variable.element as VariableElementImpl;
     expect(variableElement, isNotNull);
     expect(variableElement.initializer, isNull);
     // Build the initializer element.
     new LocalElementBuilder(new ElementHolder(), compilationUnitElement)
         .buildVariableInitializer(variableElement, variable.initializer);
     expect(variableElement.initializer, isNotNull);
   }
 
+  void test_genericFunction_isExpression() {
+    buildElementsForText('main(p) { p is Function(int a, String); }');
+    var main = compilationUnit.declarations[0] as FunctionDeclaration;
+    var body = main.functionExpression.body as BlockFunctionBody;
+    var statement = body.block.statements[0] as ExpressionStatement;
+    var expression = statement.expression as IsExpression;
+    var typeNode = expression.type as GenericFunctionType;
+    var typeElement = typeNode.type.element as GenericFunctionTypeElementImpl;
+    expect(typeElement.parameters, hasLength(2));
+    expect(typeElement.parameters[0].name, 'a');
+    expect(typeElement.parameters[1].name, '');
+  }
+
   void test_visitDefaultFormalParameter_local() {
     CompilationUnit unit = parseCompilationUnit('''
 main() {
   f({bool b: false}) {}
 }
 ''');
     var mainAst = unit.declarations.single as FunctionDeclaration;
     // Build API elements.
     FunctionElementImpl main;
     {
@@ skipping 87 matching lines @@
    * [ElementAnnotationImpl] is unresolved.
    */
   void checkAnnotation(NodeList<Annotation> metadata);
 
   /**
    * Verify that the given [element] has exactly one annotation, and that its
    * [ElementAnnotationImpl] is unresolved.
    */
   void checkMetadata(Element element);
 
+  void test_genericFunction_asTopLevelVariableType() {
+    buildElementsForText('int Function(int a, String) v;');
+    var v = compilationUnit.declarations[0] as TopLevelVariableDeclaration;
+    var typeNode = v.variables.type as GenericFunctionType;
+    var typeElement = typeNode.type.element as GenericFunctionTypeElementImpl;
+    expect(typeElement.parameters, hasLength(2));
+    expect(typeElement.parameters[0].name, 'a');
+    expect(typeElement.parameters[1].name, '');
+  }
+
   void test_metadata_fieldDeclaration() {
     List<FieldElement> fields =
         buildElementsForText('class C { @a int x, y; }').types[0].fields;
     checkMetadata(fields[0]);
     checkMetadata(fields[1]);
     expect(fields[0].metadata, same(fields[1].metadata));
   }
 
   void test_metadata_topLevelVariableDeclaration() {
     List<TopLevelVariableElement> topLevelVariables =
@@ skipping 1424 matching lines @@
     AnalysisEngine.instance.logger = logger;
     try {
       _compilationUnit = parseCompilationUnit(code);
       compilationUnit.accept(visitor);
     } finally {
       expect(logger.log, hasLength(0));
       AnalysisEngine.instance.logger = Logger.NULL;
     }
   }
 }