Add and use AnalysisCache.sources getter.

pkg/analyzer/test/src/context/cache_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.driver_test;
 
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/generated/engine.dart'
     show
         AnalysisContext,
@@ skipping 165 matching lines @@
   }
 
   void test_size() {
     int size = 4;
     for (int i = 0; i < size; i++) {
       AnalysisTarget target = new TestSource("/test$i.dart");
       cache.put(new CacheEntry(target));
     }
     expect(cache.size(), size);
   }
+
+  void test_sources() {
+    AnalysisTarget source1 = new TestSource('1.dart');
+    AnalysisTarget source2 = new TestSource('2.dart');
+    AnalysisTarget target1 = new _TestAnalysisTarget();
+    // no entries
+    expect(cache.sources, isEmpty);
+    // add source1
+    cache.put(new CacheEntry(source1));
+    expect(cache.sources, unorderedEquals([source1]));
+    // add target1
+    cache.put(new CacheEntry(target1));
+    expect(cache.sources, unorderedEquals([source1]));
+    // add source2
+    cache.put(new CacheEntry(source2));
+    expect(cache.sources, unorderedEquals([source1, source2]));
+    // remove source1
+    cache.remove(source1);
+    expect(cache.sources, unorderedEquals([source2]));
+    // remove source2
+    cache.remove(source2);
+    expect(cache.sources, isEmpty);
+  }
 }
 
 @reflectiveTest
 class CacheEntryTest extends AbstractCacheTest {
   test_explicitlyAdded() {
     AnalysisTarget target = new TestSource();
     CacheEntry entry = new CacheEntry(target);
     expect(entry.explicitlyAdded, false);
     entry.explicitlyAdded = true;
     expect(entry.explicitlyAdded, true);
@@ skipping 639 matching lines @@
     UniversalCachePartition partition = new UniversalCachePartition(null);
     TestSource source = new TestSource();
     expect(partition.isResponsibleFor(source), isTrue);
   }
 }
 
 class _InternalAnalysisContextMock extends TypedMock
     implements InternalAnalysisContext {
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
+
+class _TestAnalysisTarget implements AnalysisTarget {

[Brian Wilkerson, 2015/05/21 13:52:31]

Don't we already have this class somewhere?

+  @override
+  Source get source => null;
+}