Give a module's own credential its dial, subjects and durable consumer in mesh-sdk, so a part no longer hand-writes them (issue 1242)

go/process/account_test.go

@@ -257,3 +257,39 @@ func (h *heldSubscriber) deliver() {
 	h.mu.Unlock()
 	handle(&nats.Msg{Subject: subject})
 }
+
+// 1242: the module's own credential gives the names it reaches on the bus (its events' subjects, its own
+// stream's, its durable consumer's) and the options it dials with.
+func TestModuleAccountNamesAndDialOptions(t *testing.T) {
+	a := Account{URL: "nats://x:4222", Node: "n1", Module: "mesh-delivery-teller", User: "n1.mesh-delivery-teller", Password: "pw"}
+	for _, c := range []struct{ name, got, want string }{
+		{"event subject", a.EventSubject("put"), "mesh.mod.mesh-delivery-teller.event.put"},
+		{"own stream subject", a.StreamSubject("forge.x.pull"), "mesh.stream.mesh-delivery-teller.event.forge.x.pull"},
+		{"durable consumer", a.EventConsumerName(), "n1_mesh-delivery-teller"},
+	} {
+		if c.got != c.want {
+			t.Errorf("%s: got %q, want %q", c.name, c.got, c.want)
+		}
+	}
+	if _, err := ReadBrokerAccount(func(string) string { return " " }); err == nil || !strings.Contains(err.Error(), BrokerFileEnv) {
+		t.Errorf("no broker file set: %v", err)
+	}
+	var o nats.Options
+	for _, opt := range a.DialOptions() {
+		if err := opt(&o); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if o.Name != "n1.mesh-delivery-teller" || o.User != "n1.mesh-delivery-teller" ||
+		o.MaxReconnect != -1 || !o.RetryOnFailedConnect || o.Secure {
+		t.Errorf("dial options: %+v", o)
+	}
+	a.Fingerprint = "sha256:ab"
+	o = nats.Options{}
+	for _, opt := range a.DialOptions() {
+		_ = opt(&o)
+	}
+	if !o.Secure || o.TLSConfig == nil {
+		t.Errorf("a fingerprint did not pin the connection")
+	}
+}