Reuse CompilationUnitElement in BuildCompilationUnitElementTask.

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';
+import 'package:analyzer/src/generated/engine.dart' show CacheState;
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/resolver.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/dart.dart';
 import 'package:analyzer/task/dart.dart';
 import 'package:analyzer/task/general.dart';
 import 'package:analyzer/task/model.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../generated/test_support.dart';
@@ skipping 134 matching lines @@
     expect(task, new isInstanceOf<BuildClassConstructorsTask>());
     _fillErrorListener(CONSTRUCTORS_ERRORS);
     errorListener.assertErrorsWithCodes(
         <ErrorCode>[CompileTimeErrorCode.MIXIN_HAS_NO_CONSTRUCTORS]);
   }
 }
 
 @reflectiveTest
 class BuildCompilationUnitElementTaskTest extends _AbstractDartTaskTest {
   Source source;
+  LibrarySpecificUnit target;
 
   test_buildInputs() {
     LibrarySpecificUnit target =
         new LibrarySpecificUnit(emptySource, emptySource);
     Map<String, TaskInput> inputs =
         BuildCompilationUnitElementTask.buildInputs(target);
     expect(inputs, isNotNull);
     expect(inputs.keys, unorderedEquals(
         [BuildCompilationUnitElementTask.PARSED_UNIT_INPUT_NAME]));
   }
@@ skipping 62 matching lines @@
 part 'part.dart';
 class A {}
 class B = Object with A;
 ''');
     expect(outputs, hasLength(3));
     expect(outputs[COMPILATION_UNIT_ELEMENT], isNotNull);
     expect(outputs[RESOLVED_UNIT1], isNotNull);
     expect(outputs[COMPILATION_UNIT_CONSTANTS], isNotNull);
   }
 
+  test_perform_reuseElement() {
+    _performBuildTask(r'''
+library lib;
+class A {}
+class B = Object with A;
+''');
+    CompilationUnit unit = outputs[RESOLVED_UNIT1];
+    CompilationUnitElement unitElement = outputs[COMPILATION_UNIT_ELEMENT];
+    expect(unit, isNotNull);
+    expect(unitElement, isNotNull);
+    // invalidate RESOLVED_UNIT1
+    CacheEntry cacheEntry = analysisCache.get(target);
+    cacheEntry.setState(RESOLVED_UNIT1, CacheState.INVALID);
+    // compute again
+    _computeResult(target, RESOLVED_UNIT1);
+    expect(outputs[COMPILATION_UNIT_ELEMENT], same(unitElement));
+    expect(outputs[RESOLVED_UNIT1], isNot(same(unit)));
+  }
+
   void _performBuildTask(String content) {
     source = newSource('/test.dart', content);
-    AnalysisTarget target = new LibrarySpecificUnit(source, source);
+    target = new LibrarySpecificUnit(source, source);
     _computeResult(target, RESOLVED_UNIT1);
     expect(task, new isInstanceOf<BuildCompilationUnitElementTask>());
   }
 }
 
 @reflectiveTest
 class BuildDirectiveElementsTaskTest extends _AbstractDartTaskTest {
   test_constructor() {
     BuildDirectiveElementsTask task =
         new BuildDirectiveElementsTask(context, emptySource);
@@ skipping 2214 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);
   }
 }