swarm/network/simulation: fix multiple services issue

swarm/network/simulation/node_test.go

@@ -160,6 +160,41 @@ func TestAddNodeWithService(t *testing.T) {
 	}
 }
 
+func TestAddNodeMultipleServices(t *testing.T) {
+	sim := New(map[string]ServiceFunc{
+		"noop1": noopServiceFunc,
+		"noop2": noopService2Func,
+	})
+	defer sim.Close()
+
+	id, err := sim.AddNode()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	n := sim.Net.GetNode(id).Node.(*adapters.SimNode)
+	if n.Service("noop1") == nil {
+		t.Error("service noop1 not found on node")
+	}
+	if n.Service("noop2") == nil {
+		t.Error("service noop2 not found on node")
+	}
+}
+
+func TestAddNodeDuplicateServiceError(t *testing.T) {
+	sim := New(map[string]ServiceFunc{
+		"noop1": noopServiceFunc,
+		"noop2": noopServiceFunc,
+	})
+	defer sim.Close()
+
+	wantErr := "duplicate service: *simulation.noopService"
+	_, err := sim.AddNode()
+	if err.Error() != wantErr {
+		t.Errorf("got error %q, want %q", err, wantErr)
+	}
+}
+
 func TestAddNodes(t *testing.T) {
 	sim := New(noopServiceFuncMap)
 	defer sim.Close()

swarm/network/simulation/simulation.go

@@ -80,6 +80,9 @@ func New(services map[string]ServiceFunc) (s *Simulation) {
 
 	adapterServices := make(map[string]adapters.ServiceFunc, len(services))
 	for name, serviceFunc := range services {
+		// Scope this variables correctly
+		// as they will be in the adapterServices[name] function accessed later.
+		name, serviceFunc := name, serviceFunc
 		s.serviceNames = append(s.serviceNames, name)
 		adapterServices[name] = func(ctx *adapters.ServiceContext) (node.Service, error) {
 			b := new(sync.Map)

swarm/network/simulation/simulation_test.go

@@ -205,3 +205,34 @@ func (t *noopService) Start(server *p2p.Server) error {
 func (t *noopService) Stop() error {
 	return nil
 }
+
+// a helper function for most basic noop service
+// of a different type then noopService to test
+// multiple services on one node.
+func noopService2Func(ctx *adapters.ServiceContext, b *sync.Map) (node.Service, func(), error) {
+	return newNoopService2(), nil, nil
+}
+
+// noopService2 is the service that does not do anything
+// but implements node.Service interface.
+type noopService2 struct{}
+
+func newNoopService2() node.Service {
+	return &noopService2{}
+}
+
+func (t *noopService2) Protocols() []p2p.Protocol {
+	return []p2p.Protocol{}
+}
+
+func (t *noopService2) APIs() []rpc.API {
+	return []rpc.API{}
+}
+
+func (t *noopService2) Start(server *p2p.Server) error {
+	return nil
+}
+
+func (t *noopService2) Stop() error {
+	return nil
+}