implement ByteStreamClientChannel close

pkg/analysis_server/test/channel_test.dart

Index: pkg/analysis_server/test/channel_test.dart
diff --git a/pkg/analysis_server/test/channel_test.dart b/pkg/analysis_server/test/channel_test.dart
index 3c31b8502b5cb90b31bb9519cca32998a559c5ec..95e9cc655a8b73d08fdf9dc1043aebba47523ca7 100644
--- a/pkg/analysis_server/test/channel_test.dart
+++ b/pkg/analysis_server/test/channel_test.dart
@@ -28,6 +28,7 @@ main() {
   });
   group('ByteStreamClientChannel',  () {
     setUp(ByteStreamClientChannelTest.setUp);
+    test('close', ByteStreamClientChannelTest.close);
     test('listen_notification', ByteStreamClientChannelTest.listen_notification);
     test('listen_response', ByteStreamClientChannelTest.listen_response);
     test('sendRequest', ByteStreamClientChannelTest.sendRequest);
@@ -184,11 +185,16 @@ class ByteStreamClientChannelTest {
 
   /**
    * Sink that may be used to deliver data to the channel, as though it's
-   * coming from the client.
+   * coming from the server.
    */
   static IOSink inputSink;
 
   /**
+   * Sink through which the channel delivers data to the server.
+   */
+  static IOSink outputSink;
+
+  /**
    * Stream of lines sent back to the client by the channel.
    */
   static Stream<String> outputLineStream;
@@ -199,10 +205,27 @@ class ByteStreamClientChannelTest {
     var outputStream = new StreamController<List<int>>();
     outputLineStream = outputStream.stream.transform((new Utf8Codec()).decoder
         ).transform(new LineSplitter());
-    var outputSink = new IOSink(outputStream);
+    outputSink = new IOSink(outputStream);
     channel = new ByteStreamClientChannel(inputStream.stream, outputSink);
   }
 
+  static Future close() {
+    bool doneCalled = false;
+    bool closeCalled = false;
+    // add listener so that outputSink will trigger done/close futures
+    outputLineStream.listen((_) { /* no-op */ });
+    outputSink.done.then((_) {
+      doneCalled = true;
+    });
+    channel.close().then((_) {
+      closeCalled = true;
+    });
+    return pumpEventQueue().then((_) {
+      expect(doneCalled, isTrue);
+      expect(closeCalled, isTrue);
+    });
+  }
+
   static Future listen_notification() {
     List<Notification> notifications = [];
     channel.notificationStream.forEach((n) => notifications.add(n));