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Author: Hixie

lib/ui/hooks.dart

@@ -254,6 +254,8 @@ void _invoke(void callback()?, Zone zone) {
 }
 
 /// Invokes [callback] inside the given [zone] passing it [arg].
+///
+/// The 1 in the name refers to the number of arguments expected by the callback.
 void _invoke1<A>(void callback(A a)?, Zone zone, A arg) {
   if (callback == null)
     return;
@@ -268,6 +270,8 @@ void _invoke1<A>(void callback(A a)?, Zone zone, A arg) {
 }
 
 /// Invokes [callback] inside the given [zone] passing it [arg1] and [arg2].
+///
+/// The 2 in the name refers to the number of arguments expected by the callback.
 void _invoke2<A1, A2>(void callback(A1 a1, A2 a2)?, Zone zone, A1 arg1, A2 arg2) {
   if (callback == null)
     return;
@@ -284,6 +288,8 @@ void _invoke2<A1, A2>(void callback(A1 a1, A2 a2)?, Zone zone, A1 arg1, A2 arg2)
 }
 
 /// Invokes [callback] inside the given [zone] passing it [arg1], [arg2], and [arg3].
+///
+/// The 3 in the name refers to the number of arguments expected by the callback.
 void _invoke3<A1, A2, A3>(void callback(A1 a1, A2 a2, A3 a3)?, Zone zone, A1 arg1, A2 arg2, A3 arg3) {
   if (callback == null)
     return;

testing/dart/channel_buffers_test.dart

@@ -36,7 +36,7 @@ void main() {
     });
   });
 
-  test('deprecated drain is sync', () async {
+  test('drain is sync', () async {
     const String channel = 'foo';
     final ByteData data = _makeByteData('message');
     final ui.ChannelBuffers buffers = ui.ChannelBuffers();
@@ -78,7 +78,7 @@ void main() {
     expect(didCall, equals(false));
   });
 
-  test('empty', () async {
+  test('drain when empty', () async {
     const String channel = 'foo';
     final ui.ChannelBuffers buffers = ui.ChannelBuffers();
     bool didCall = false;
@@ -240,4 +240,51 @@ void main() {
       '-9',
     ]);
   });
+
+  test('ChannelBuffers.clearListener', () async {
+    final List<String> log = <String>[];
+    final ui.ChannelBuffers buffers = ui.ChannelBuffers();
+    final ByteData one = _makeByteData('one');
+    final ByteData two = _makeByteData('two');
+    final ByteData three = _makeByteData('three');
+    final ByteData four = _makeByteData('four');
+    buffers.handleMessage(_makeByteData('resize\ra\r10'));
+    buffers.push('a', one, (ByteData data) { });
+    buffers.push('a', two, (ByteData data) { });
+    buffers.push('a', three, (ByteData data) { });
+    log.add('-1');
+    buffers.setListener('a', (ByteData data, ui.PlatformMessageResponseCallback callback) {
+      log.add('a1: ${utf8.decode(data.buffer.asUint8List())}');
+    });
+    await null; // handles one
+    log.add('-2');
+    buffers.clearListener('a');
+    await null;
+    log.add('-3');
+    buffers.setListener('a', (ByteData data, ui.PlatformMessageResponseCallback callback) {
+      log.add('a2: ${utf8.decode(data.buffer.asUint8List())}');
+    });
+    log.add('-4');
+    await null;
+    buffers.push('a', four, (ByteData data) { });
+    log.add('-5');
+    await null;
+    log.add('-6');
+    await null;
+    log.add('-7');
+    await null;
+    expect(log, <String>[
+      '-1',
+      'a1: one',
+      '-2',
+      '-3',
+      '-4',
+      'a2: two',
+      '-5',
+      'a2: three',
+      '-6',
+      'a2: four',
+      '-7',
+    ]);
+  });
 }