test: add tests for signals client

Signed-off-by: Heikki Hellgren <heikki.hellgren@op.fi>

plugins/signals-react/src/api/SignalsApi.ts

@@ -23,10 +23,7 @@ export const signalsApiRef = createApiRef<SignalsApi>({
 
 /** @public */
 export type SignalsApi = {
-  subscribe(
-    onMessage: (message: JsonObject, topic?: string) => void,
-    topic: string,
-  ): string;
+  subscribe(topic: string, onMessage: (message: JsonObject) => void): string;
 
   unsubscribe(subscription: string): void;
 };

plugins/signals-react/src/hooks/useSignalsApi.ts

@@ -27,7 +27,7 @@ export const useSignalsApi = (
   const [subscription, setSubscription] = useState<null | string>(null);
   useEffect(() => {
     if (!subscription) {
-      const sub = signals.subscribe(onMessage, topic);
+      const sub = signals.subscribe(topic, onMessage);
       setSubscription(sub);
     }
   }, [subscription, signals, onMessage, topic]);