consul: adding StopWatch test

consul/state_store_test.go

@@ -127,6 +127,37 @@ func TestGetNodes(t *testing.T) {
 	}
 }
 
+func TestGetNodes_Watch_StopWatch(t *testing.T) {
+	store, err := testStateStore()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer store.Close()
+
+	notify1 := make(chan struct{}, 1)
+	notify2 := make(chan struct{}, 1)
+
+	store.Watch(store.QueryTables("Nodes"), notify1)
+	store.Watch(store.QueryTables("Nodes"), notify2)
+	store.StopWatch(store.QueryTables("Nodes"), notify2)
+
+	if err := store.EnsureNode(40, structs.Node{"foo", "127.0.0.1"}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	select {
+	case <-notify1:
+	default:
+		t.Fatalf("should be notified")
+	}
+
+	select {
+	case <-notify2:
+		t.Fatalf("should not be notified")
+	default:
+	}
+}
+
 func BenchmarkGetNodes(b *testing.B) {
 	store, err := testStateStore()
 	if err != nil {