p2p: add channel buffers to avoid goroutine leaks in tests (ethereum#24929)

Author: Chain-Fox

p2p/discover/v4_udp_test.go

@@ -313,7 +313,7 @@ func TestUDPv4_findnodeMultiReply(t *testing.T) {
 	test.table.db.UpdateLastPingReceived(rid, test.remoteaddr.IP, time.Now())
 
 	// queue a pending findnode request
-	resultc, errc := make(chan []*node), make(chan error)
+	resultc, errc := make(chan []*node, 1), make(chan error, 1)
 	go func() {
 		rid := encodePubkey(&test.remotekey.PublicKey).id()
 		ns, err := test.udp.findnode(rid, test.remoteaddr, testTarget)

p2p/dnsdisc/client_test.go

@@ -265,7 +265,7 @@ func TestIteratorEmptyTree(t *testing.T) {
 	resolver.add(tree1.ToTXT("n"))
 
 	// Start the iterator.
-	node := make(chan *enode.Node)
+	node := make(chan *enode.Node, 1)
 	it, err := c.NewIterator(url)
 	if err != nil {
 		t.Fatal(err)

p2p/simulations/examples/ping-pong.go

@@ -139,7 +139,7 @@ const (
 func (p *pingPongService) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
 	log := p.log.New("peer.id", peer.ID())
 
-	errC := make(chan error)
+	errC := make(chan error, 1)
 	go func() {
 		for range time.Tick(10 * time.Second) {
 			log.Info("sending ping")

p2p/simulations/http_test.go

@@ -596,7 +596,7 @@ func TestHTTPSnapshot(t *testing.T) {
 	network, s := testHTTPServer(t)
 	defer s.Close()
 
-	var eventsDone = make(chan struct{})
+	var eventsDone = make(chan struct{}, 1)
 	count := 1
 	eventsDoneChan := make(chan *Event)
 	eventSub := network.Events().Subscribe(eventsDoneChan)