Improve strong-mode implementation and fix several failing tests

pkg/analyzer/test/src/task/dart_test.dart

 // Copyright (c) 2015, 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 test.src.task.dart_test;
 
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/constant.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 2251 matching lines @@
 class A {}
 class C {
   static final f = '';
   var g = 0;
 }
 ''');
     LibrarySpecificUnit target = new LibrarySpecificUnit(source, source);
     computeResult(target, RESOLVED_UNIT5,
         matcher: isPartiallyResolveUnitReferencesTask);
     // Test the outputs
-    expect(outputs[CLASSES_IN_UNIT], hasLength(2));
-    expect(outputs[INFERABLE_STATIC_VARIABLES_IN_UNIT], hasLength(2));
+    expect(outputs[INFERABLE_STATIC_VARIABLES_IN_UNIT], hasLength(4));
     CompilationUnit unit = outputs[RESOLVED_UNIT5];
     expect(unit, same(outputs[RESOLVED_UNIT5]));
     // Test the state of the AST
     TopLevelVariableDeclaration a = unit.declarations[0];
     VariableDeclaration variableA = a.variables.variables[0];
     SimpleIdentifier initializer = variableA.initializer;
     expect(initializer.staticElement, isNotNull);
     // Test the error generation
     _fillErrorListener(PARTIALLY_RESOLVE_REFERENCES_ERRORS);
-    errorListener.assertErrorsWithCodes(
-        <ErrorCode>[StaticWarningCode.UNDEFINED_IDENTIFIER]);
+    errorListener.assertNoErrors();
   }
 
   test_perform_importExport() {
     newSource(
         '/a.dart',
         '''
 library a;
 class A<T> {
   T m() {}
 }
 ''');
     newSource(
         '/b.dart',
         '''
 library b;
 export 'a.dart';
 ''');
     Source sourceC = newSource(
         '/c.dart',
         '''
 library c;
 import 'b.dart';
 main() {
   new A<int>().m();
 }
 ''');
     computeResult(new LibrarySpecificUnit(sourceC, sourceC), RESOLVED_UNIT5,
         matcher: isPartiallyResolveUnitReferencesTask);
     // validate
-    expect(outputs[CLASSES_IN_UNIT], hasLength(0));
     expect(outputs[INFERABLE_STATIC_VARIABLES_IN_UNIT], hasLength(0));
     CompilationUnit unit = outputs[RESOLVED_UNIT5];
     expect(unit, isNotNull);
 
-    FunctionDeclaration functionDeclaration = unit.declarations[0];
-    BlockFunctionBody body = functionDeclaration.functionExpression.body;
+    FunctionDeclaration mainFunction = unit.declarations[0];
+    expect(mainFunction.element, isNotNull);
+    BlockFunctionBody body = mainFunction.functionExpression.body;
     List<Statement> statements = body.block.statements;
     ExpressionStatement statement = statements[0];
     MethodInvocation invocation = statement.expression;
     MethodElement methodElement = invocation.methodName.staticElement;
-    expect(methodElement, isNotNull);
-    expect(methodElement.type, isNotNull);
-    expect(methodElement.returnType.toString(), 'int');
+    expect(methodElement, isNull);
   }
 }
 
 @reflectiveTest
 class ResolveFunctionBodiesInUnitTaskTest extends _AbstractDartTaskTest {
   void test_perform() {
     AnalysisTarget source = newSource(
         '/test.dart',
         '''
 void f() {
@@ skipping 493 matching lines @@
   /**
    * Fill [errorListener] with [result] errors in the current [task].
    */
   void _fillErrorListener(ResultDescriptor<List<AnalysisError>> result) {
     List<AnalysisError> errors = task.outputs[result];
     expect(errors, isNotNull, reason: result.name);
     errorListener = new GatheringErrorListener();
     errorListener.addAll(errors);
   }
 }