Fix mDNS connection tests on macOS

Author: JoTurk

peerconnection_go_test.go

@@ -16,6 +16,7 @@ import (
 	"math/big"
 	"net"
 	"regexp"
+	"runtime"
 	"slices"
 	"strings"
 	"sync"
@@ -810,6 +811,19 @@ func TestPopulateLocalCandidates(t *testing.T) {
 	})
 }
 
+func configureMulticastDNS(s *SettingEngine) {
+	s.SetICEMulticastDNSMode(ice.MulticastDNSModeQueryAndGather)
+	if runtime.GOOS != "darwin" {
+		return
+	}
+
+	s.SetNetworkTypes([]NetworkType{NetworkTypeUDP4})
+	s.SetIncludeLoopbackCandidate(true)
+	s.SetIPFilter(func(ip net.IP) bool {
+		return ip.IsLoopback() && ip.To4() != nil
+	})
+}
+
 // Assert that two agents that only generate mDNS candidates can connect.
 func TestMulticastDNSCandidates(t *testing.T) {
 	lim := test.TimeOut(time.Second * 30)
@@ -819,20 +833,20 @@ func TestMulticastDNSCandidates(t *testing.T) {
 	defer report()
 
 	s := SettingEngine{}
-	s.SetICEMulticastDNSMode(ice.MulticastDNSModeQueryAndGather)
+	configureMulticastDNS(&s)
 
 	pcOffer, pcAnswer, err := NewAPI(WithSettingEngine(s)).newPair(Configuration{})
-	assert.NoError(t, err)
-
-	assert.NoError(t, signalPair(pcOffer, pcAnswer))
+	require.NoError(t, err)
+	defer closePairNow(t, pcOffer, pcAnswer)
 
 	onDataChannel, onDataChannelCancel := context.WithCancel(context.Background())
+	defer onDataChannelCancel()
 	pcAnswer.OnDataChannel(func(*DataChannel) {
 		onDataChannelCancel()
 	})
-	<-onDataChannel.Done()
 
-	closePairNow(t, pcOffer, pcAnswer)
+	require.NoError(t, signalPair(pcOffer, pcAnswer))
+	<-onDataChannel.Done()
 }
 
 func TestMulticastDNSHostNameConnection(t *testing.T) {
@@ -849,11 +863,11 @@ func TestMulticastDNSHostNameConnection(t *testing.T) {
 	}
 
 	offerSettingEngine := SettingEngine{}
-	offerSettingEngine.SetICEMulticastDNSMode(ice.MulticastDNSModeQueryAndGather)
+	configureMulticastDNS(&offerSettingEngine)
 	offerSettingEngine.SetMulticastDNSHostName(offerHostName)
 
 	answerSettingEngine := SettingEngine{}
-	answerSettingEngine.SetICEMulticastDNSMode(ice.MulticastDNSModeQueryAndGather)
+	configureMulticastDNS(&answerSettingEngine)
 	answerSettingEngine.SetMulticastDNSHostName(answerHostName)
 
 	pcOffer, err := NewAPI(WithSettingEngine(offerSettingEngine)).NewPeerConnection(Configuration{})