add test reproduce goroutine leaks on datachannel mux

datachannel_test.go

@@ -10,6 +10,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/pion/ice/v3"
 	"github.com/pion/transport/v3/test"
 	"github.com/stretchr/testify/assert"
 )
@@ -360,6 +361,17 @@ func TestDataChannel_Close(t *testing.T) {
 		assert.NoError(t, dc.Close())
 		closePairNow(t, offerPC, answerPC)
 	})
+
+	t.Run("Close after PeerConnection With Mux Closed", func(t *testing.T) {
+		offerPC, answerPC, err := newPairWithMux()
+		assert.NoError(t, err)
+
+		dc, err := offerPC.CreateDataChannel(expectedLabel, nil)
+		assert.NoError(t, err)
+
+		closePairNow(t, offerPC, answerPC)
+		assert.NoError(t, dc.Close())
+	})
 }
 
 func TestDataChannelParameters(t *testing.T) {
@@ -518,3 +530,30 @@ func TestDataChannelParameters(t *testing.T) {
 		closeReliabilityParamTest(t, offerPC, answerPC, done)
 	})
 }
+
+func newPairWithMux() (*PeerConnection, *PeerConnection, error) {
+	settingEngine := SettingEngine{}
+
+	// Configure our SettingEngine to use our UDPMux. By default a PeerConnection has
+	// no global state. The API+SettingEngine allows the user to share state between them.
+	// In this case we are sharing our listening port across many.
+	// Listen on UDP Port 8443, will be used for all WebRTC traffic
+	mux, err := ice.NewMultiUDPMuxFromPort(8443)
+	if err != nil {
+		panic(err)
+	}
+
+	settingEngine.SetICEUDPMux(mux)
+	api := NewAPI(WithSettingEngine(settingEngine))
+	pca, err := api.NewPeerConnection(Configuration{})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	pcb, err := NewPeerConnection(Configuration{})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return pca, pcb, nil
+}