Nsryjdtyk

I have an epic that catch each dispatch of getting status (just item from state, like state.process:{ status: fail, success, inWork}, not an request status like 200, 500 etc).
When status == success (by getting status from state) i need to dispatch another action like SET_STATUS_SUCCESS

const getStatus = (action, state) =>

    action.pipe(

        ofType(GET_STATUS),

        withLatestFrom(state),

        mergeMap(([action, state]) => {

            const { status } = state.api.process; //here is what i need, there is no problem with status.

            if (status === "success") {

              return mapTo(SET_STATUS_SUCCESS) //got nothing and error.

}

        })

    );

Now i receive error:

Uncaught TypeError: You provided 'function (source) { return
source.lift(new MapToOperator(value)); }' where a stream was expected.
You can provide an Observable, Promise, Array, or Iterable.
at subscribeTo (subscribeTo.js:41)

What should i do? I tried just return setStatusSuccess action but it doesn't work too.

You need to return an observable from the function you pass to mergeMap. Try this:

const getStatus = (action, state) =>

  action.pipe(

    ofType(GET_STATUS),

    withLatestFrom(state),

    mergeMap(([action, state]) => {

      const { status } = state.api.process;



      if (status === 'success') {

        return of({ type: SET_STATUS_SUCCESS });

      } else {

        return EMPTY;

      }

    }),

  );

of and EMPTY are imported from rxjs.