Explicitly remove AnalysisContext from ContextCodec.

pkg/analysis_server/test/index/split_store_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 test.index.split.store;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/src/index/split_store.dart';
@@ skipping 52 matching lines @@
   }
   fail('Expected to find Location'
       '(element=$element, offset=$offset, length=$length)');
 }
 
 
 @ReflectiveTestCase()
 class _ContextCodecTest {
   ContextCodec codec = new ContextCodec();
 
-  void test_all() {
+  void test_encode_decode() {
     AnalysisContext contextA = new _MockAnalysisContext('contextA');
     AnalysisContext contextB = new _MockAnalysisContext('contextB');
     int idA = codec.encode(contextA);
     int idB = codec.encode(contextB);
+    expect(idA, codec.encode(contextA));
+    expect(idB, codec.encode(contextB));
     expect(codec.decode(idA), contextA);
     expect(codec.decode(idB), contextB);
   }
+
+  void test_remove() {
+    // encode
+    {
+      AnalysisContext context = new _MockAnalysisContext('context');
+      // encode
+      int id = codec.encode(context);
+      expect(id, 0);
+      expect(codec.decode(id), context);
+      // remove
+      codec.remove(context);
+      expect(codec.decode(id), isNull);
+    }
+    // encode again
+    {
+      AnalysisContext context = new _MockAnalysisContext('context');
+      // encode
+      int id = codec.encode(context);
+      expect(id, 1);
+      expect(codec.decode(id), context);
+    }
+  }
 }
 
 
 @ReflectiveTestCase()
 class _ElementCodecTest {
   ElementCodec codec;
   AnalysisContext context = new _MockAnalysisContext('context');
   StringCodec stringCodec = new StringCodec();
 
   void setUp() {
@@ skipping 1241 matching lines @@
 class _StringCodecTest {
   StringCodec codec = new StringCodec();
 
   void test_all() {
     int idA = codec.encode('aaa');
     int idB = codec.encode('bbb');
     expect(codec.decode(idA), 'aaa');
     expect(codec.decode(idB), 'bbb');
   }
 }