Get memento objects from tasks, remember in cache and pass back to tasks.

pkg/analyzer/test/src/task/model_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.model_test;
 
 import 'package:analyzer/src/generated/engine.dart' hide AnalysisTask;
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/task/model.dart';
 import 'package:analyzer/task/model.dart';
@@ skipping 40 matching lines @@
   test_getRequiredSource() {
     AnalysisTarget target = new TestSource();
     AnalysisTask task = new TestAnalysisTask(null, target);
     expect(task.getRequiredSource(), target);
   }
 }
 
 @reflectiveTest
 class ContributionPointImplTest extends EngineTestCase {
   test_contributors_empty() {
-    CompositeResultDescriptorImpl point = new CompositeResultDescriptorImpl('point');
+    CompositeResultDescriptorImpl point =
+        new CompositeResultDescriptorImpl('point');
     List<ResultDescriptor> contributors = point.contributors;
     expect(contributors, isEmpty);
   }
 
   test_contributors_nonEmpty() {
     ResultDescriptorImpl result1 = new ResultDescriptorImpl('result1', null);
     ResultDescriptorImpl result2 = new ResultDescriptorImpl('result2', null);
-    CompositeResultDescriptorImpl point = new CompositeResultDescriptorImpl('point');
+    CompositeResultDescriptorImpl point =
+        new CompositeResultDescriptorImpl('point');
     point.recordContributor(result1);
     point.recordContributor(result2);
     List<ResultDescriptor> contributors = point.contributors;
     expect(contributors, isNotNull);
     expect(contributors, hasLength(2));
     if (!(contributors[0] == result1 && contributors[1] == result2) ||
         (contributors[0] == result2 && contributors[1] == result1)) {
       fail("Invalid contributors: $contributors");
     }
   }
 
   test_create() {
     expect(new CompositeResultDescriptorImpl('name'), isNotNull);
   }
 
   test_name() {
     String name = 'point';
-    CompositeResultDescriptorImpl point = new CompositeResultDescriptorImpl(name);
+    CompositeResultDescriptorImpl point =
+        new CompositeResultDescriptorImpl(name);
     expect(point.name, name);
   }
 }
 
 @reflectiveTest
 class ResultDescriptorImplTest extends EngineTestCase {
   test_create_withContribution() {
-    CompositeResultDescriptorImpl point = new CompositeResultDescriptorImpl('point');
+    CompositeResultDescriptorImpl point =
+        new CompositeResultDescriptorImpl('point');
     ResultDescriptorImpl result =
         new ResultDescriptorImpl('result', null, contributesTo: point);
     expect(result, isNotNull);
     List<ResultDescriptor> contributors = point.contributors;
     expect(contributors, unorderedEquals([result]));
   }
 
   test_create_withoutContribution() {
     expect(new ResultDescriptorImpl('name', null), isNotNull);
   }
@@ skipping 31 matching lines @@
   test_createTask() {
     BuildTask buildTask =
         (context, target) => new TestAnalysisTask(context, target);
     CreateTaskInputs createTaskInputs = (target) {};
     List<ResultDescriptor> results = <ResultDescriptor>[];
     TaskDescriptorImpl descriptor =
         new TaskDescriptorImpl('name', buildTask, createTaskInputs, results);
     AnalysisContext context = null;
     AnalysisTarget target = new TestSource();
     Map<String, dynamic> inputs = {};
-    AnalysisTask createTask = descriptor.createTask(context, target, inputs);
+    String inputMemento = 'main() {}';
+    AnalysisTask createTask =
+        descriptor.createTask(context, target, inputs, inputMemento);
     expect(createTask, isNotNull);
     expect(createTask.context, context);
     expect(createTask.inputs, inputs);
+    expect(createTask.inputMemento, inputMemento);
     expect(createTask.target, target);
   }
 }