# How do i write an NgRx 8 Effect that triggers an action from a promise

I am struggling to grasp NgRx Effects.

Using the latest release, version 8, i have written the following effect which combines the observable with a promise and am struggling to grasp how to write it correctly.

Is this guaranteed to catch all possible errors?

authLogin$= createEffect(() => this.actions$.pipe(
switchMap(async(action) => {
try {
return AuthActions.authSuccess(userState);
}
catch (error) {

I am also not clear on whether or not i should be using the last bit of this configuration: { resubscribeOnError: false } Does this mean subsequent execution will create an entirely new observable?