fix: stop embedded NATS test servers sleeping 25ms on startup (#804)

spinifex/testutil/nats.go

@@ -25,7 +25,7 @@ func StartTestNATS(t testing.TB) (*server.Server, *nats.Conn) {
 	ns, err := server.NewServer(opts)
 	require.NoError(t, err)
 	go ns.Start()
-	require.True(t, ns.ReadyForConnections(5*time.Second))
+	waitReadyForConnections(t, ns)
 	t.Cleanup(func() { ns.Shutdown() })
 
 	nc, err := nats.Connect(ns.ClientURL())
@@ -34,6 +34,20 @@ func StartTestNATS(t testing.TB) (*server.Server, *nats.Conn) {
 	return ns, nc
 }
 
+// waitReadyForConnections spins until the server accepts connections. Calling
+// ReadyForConnections with a longer timeout makes it sleep 25ms per attempt,
+// which every embedded server in the suite would otherwise pay.
+func waitReadyForConnections(t testing.TB, ns *server.Server) {
+	t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	for !ns.ReadyForConnections(time.Millisecond) {
+		if time.Now().After(deadline) {
+			t.Fatal("embedded NATS server not ready for connections within 5s")
+		}
+		time.Sleep(200 * time.Microsecond)
+	}
+}
+
 // StartTestJetStream starts an embedded NATS server with JetStream enabled
 // and returns the server, a connected client, and a jetstream package handle.
 // All resources are cleaned up via t.Cleanup.
@@ -50,7 +64,7 @@ func StartTestJetStream(t *testing.T) (*server.Server, *nats.Conn, jetstream.Jet
 	ns, err := server.NewServer(opts)
 	require.NoError(t, err)
 	go ns.Start()
-	require.True(t, ns.ReadyForConnections(5*time.Second))
+	waitReadyForConnections(t, ns)
 	t.Cleanup(func() { ns.Shutdown() })
 
 	nc, err := nats.Connect(ns.ClientURL())