Gracefully close connecting channels

datachannel.go

@@ -322,6 +322,9 @@ func (d *DataChannel) handleOpen(dc *datachannel.DataChannel, isRemote, isAlread
 	d.mu.Lock()
 	if d.isGracefulClosed {
 		d.mu.Unlock()
+		dc.Close() // nolint:errcheck,gosec
+		d.onClose()
+
 		return
 	}
 	d.dataChannel = dc
@@ -346,16 +349,21 @@ func (d *DataChannel) handleOpen(dc *datachannel.DataChannel, isRemote, isAlread
 	}
 
 	d.mu.Lock()
-	defer d.mu.Unlock()
 
 	if d.isGracefulClosed {
+		d.mu.Unlock() // we unlock before we call d.onClose to avoid side effects
+		dc.Close()    // nolint:errcheck,gosec
+		d.onClose()
+
 		return
 	}
 
 	if !d.api.settingEngine.detach.DataChannels {
 		d.readLoopActive = make(chan struct{})
 		go d.readLoop()
 	}
+
+	d.mu.Unlock()
 }
 
 // OnError sets an event handler which is invoked when

datachannel_test.go

@@ -455,6 +455,81 @@ func TestDataChannelParameters(t *testing.T) {
 		closeReliabilityParamTest(t, offerPC, answerPC, done)
 	})
 
+	// Test if onClose is fired for self and remote after Close is called
+	t.Run("close open channels", func(t *testing.T) {
+		options := &DataChannelInit{}
+
+		offerPC, answerPC, dc, done := setUpDataChannelParametersTest(t, options)
+
+		answerPC.OnDataChannel(func(dataChannel *DataChannel) {
+			// Make sure this is the data channel we were looking for. (Not the one
+			// created in signalPair).
+			if dataChannel.Label() != expectedLabel {
+				return
+			}
+
+			dataChannel.OnOpen(func() {
+				assert.NoError(t, dataChannel.Close())
+			})
+
+			dataChannel.OnClose(func() {
+				done <- true
+			})
+		})
+
+		dc.OnClose(func() {
+			done <- true
+		})
+
+		assert.NoError(t, signalPair(offerPC, answerPC))
+
+		// Offer and Answer OnClose
+		<-done
+		<-done
+
+		assert.NoError(t, offerPC.Close())
+		assert.NoError(t, answerPC.Close())
+	})
+
+	// Test if OnClose is fired for self and remote after Close is called on non-established channel
+	// https://github.com/pion/webrtc/issues/2659
+	t.Run("Close connecting channels", func(t *testing.T) {
+		options := &DataChannelInit{}
+
+		offerPC, answerPC, dc, done := setUpDataChannelParametersTest(t, options)
+
+		answerPC.OnDataChannel(func(dataChannel *DataChannel) {
+			// Make sure this is the data channel we were looking for. (Not the one
+			// created in signalPair).
+			if dataChannel.Label() != expectedLabel {
+				return
+			}
+
+			dataChannel.OnOpen(func() {
+				t.Fatal("OnOpen must not be fired after we call Close")
+			})
+
+			dataChannel.OnClose(func() {
+				done <- true
+			})
+
+			assert.NoError(t, dataChannel.Close())
+		})
+
+		dc.OnClose(func() {
+			done <- true
+		})
+
+		assert.NoError(t, signalPair(offerPC, answerPC))
+
+		// Offer and Answer OnClose
+		<-done
+		<-done
+
+		assert.NoError(t, offerPC.Close())
+		assert.NoError(t, answerPC.Close())
+	})
+
 	t.Run("Negotiated exchange", func(t *testing.T) {
 		const expectedMessage = "Hello World"