Always build elements, then match and restore if matches.

pkg/analyzer/test/generated/incremental_resolver_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 engine.incremental_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
@@ skipping 1808 matching lines @@
 class A {}
 class B extends Object with A {}
 ''');
   }
 
   void _assertCompilationUnitMatches(bool expectMatch, String oldContent,
       String newContent) {
     Source source = addSource(oldContent);
     LibraryElement library = resolve(source);
     CompilationUnit oldUnit = resolveCompilationUnit(source, library);
+    // parse
     CompilationUnit newUnit = ParserTestCase.parseCompilationUnit(newContent);
+    // build elements
+    {
+      ElementHolder holder = new ElementHolder();
+      ElementBuilder builder = new ElementBuilder(holder);
+      newUnit.accept(builder);
+    }
+    // match
     DeclarationMatcher matcher = new DeclarationMatcher();
     expect(matcher.matches(newUnit, oldUnit.element), expectMatch);
   }
 }
 
 
 class IncrementalResolverTest extends ResolverTestCase {
   Source source;
   String code;
   LibraryElement library;
@@ skipping 33 matching lines @@
     _resolveUnit(r'''
 class A {
   int f;
   A(int a, int b) : f = a + b {
     int a = 42;
   }
 }''');
     _resolve(_editString('+', '*'), _isExpression);
   }
 
+  void test_constructor_label_add() {
+    _resolveUnit(r'''
+class A {
+  A() {
+    return 42;
+  }
+}
+''');
+    _resolve(_editString('return', 'label: return'), _isBlock);
+  }
+
+  void test_constructor_localVariable_add() {
+    _resolveUnit(r'''
+class A {
+  A() {
+    42;
+  }
+}
+''');
+    _resolve(_editString('42;', 'var res = 42;'), _isBlock);
+  }
+
   void test_constructor_superConstructorInvocation() {
     _resolveUnit(r'''
 class A {
   A(int p);
 }
 class B extends A {
   B(int a, int b) : super(a + b);
 }
 ''');
     _resolve(_editString('+', '*'), _isExpression);
@@ skipping 2033 matching lines @@
   }
 
   @override
   visitYieldStatement(YieldStatement node) {
     YieldStatement other = this.other;
     _visitNode(node.expression, other.expression);
   }
 
   void _verifyElement(Element a, Element b) {
     if (a != b) {
+      print(a.location);
+      print(b.location);
       fail('Expected: $b\n  Actual: $a');
     }
     if (a == null && b == null) {
       return;
     }
     if (a.nameOffset != b.nameOffset) {
       fail('Expected: ${b.nameOffset}\n  Actual: ${a.nameOffset}');
     }
   }
 
@@ skipping 49 matching lines @@
     _visitList(node.metadata, other.metadata);
     _visitNode(node.identifier, other.identifier);
   }
 
   static void assertSameResolution(CompilationUnit actual,
       CompilationUnit expected) {
     _SameResolutionValidator validator = new _SameResolutionValidator(expected);
     actual.accept(validator);
   }
 }