pacify the race detector in TestGossipsubFanoutExpiry

gossipsub_test.go

@@ -297,18 +297,25 @@ func TestGossipsubFanoutExpiry(t *testing.T) {
 		}
 	}
 
+	psubs[0].eval <- func() {
 		if len(psubs[0].rt.(*GossipSubRouter).fanout) == 0 {
 			t.Fatal("owner has no fanout")
 		}
+	}
 
 	// wait for TTL to expire fanout peers in owner
 	time.Sleep(time.Second * 2)
 
+	psubs[0].eval <- func() {
 		if len(psubs[0].rt.(*GossipSubRouter).fanout) > 0 {
 			t.Fatal("fanout hasn't expired")
 		}
 	}
 
+	// wait for it to run in the event loop
+	time.Sleep(10 * time.Millisecond)
+}
+
 func TestGossipsubGossip(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()