go/pubsub: handle nil static cfg (#2297)

Author: fredr

runtimes/go/pubsub/topic.go

@@ -36,6 +36,7 @@ func newTopic[T any](mgr *Manager, name string, cfg TopicConfig) *Topic[T] {
 	if mgr.static.Testing {
 		return &Topic[T]{
 			appCfg:         cfg,
+			staticCfg:      mgr.static.PubsubTopics[name],
 			mgr:            mgr,
 			runtimeCfg:     &config.PubsubTopic{EncoreName: name},
 			topic:          test.NewTopic[T](mgr.ts, name),
@@ -165,16 +166,19 @@ func (t *Topic[T]) Publish(ctx context.Context, msg T) (id string, err error) {
 	curr := t.mgr.rt.Current()
 	var startEventID trace2.EventID
 	if curr.Req != nil && curr.Trace != nil {
+		desc := &model.PubSubTopicDesc{
+			Topic: t.runtimeCfg.EncoreName,
+		}
+		if t.staticCfg != nil {
+			desc.ScrubPaths = t.staticCfg.ScrubPaths
+		}
 		startEventID = curr.Trace.PubsubPublishStart(trace2.PubsubPublishStartParams{
 			EventParams: trace2.EventParams{
 				TraceID: curr.Req.TraceID,
 				SpanID:  curr.Req.SpanID,
 				Goid:    curr.Goctr,
 			},
-			Desc: &model.PubSubTopicDesc{
-				Topic:      t.runtimeCfg.EncoreName,
-				ScrubPaths: t.staticCfg.ScrubPaths,
-			},
+			Desc:    desc,
 			Message: data,
 			Stack:   stack.Build(1),
 		})