[Solved] Consider this effect:saveItem$ = createEffect(() => this.actions$.pipe( ofType('SAVE_ITEM'), exhaustMap(action => this.api.save(action.payload).pipe( map(() => ({ type:... | Angular

Angular - State Management

Consider this effect:

saveItem$ = createEffect(() => this.actions$.pipe(
  ofType('SAVE_ITEM'),
  exhaustMap(action => this.api.save(action.payload).pipe(
    map(() => ({ type: 'SAVE_SUCCESS' })),
    catchError(() => of({ type: 'SAVE_FAILURE' }))
  ))
))

What happens if multiple 'SAVE_ITEM' actions are dispatched quickly?

AOnly the first save runs; others are ignored until it completes

BAll saves run concurrently

COnly the last save runs, previous ones are canceled

DNo saves run due to error

Step-by-Step Solution

Solution:

Step 1: Understand exhaustMap behavior
exhaustMap ignores new source emissions while the previous inner observable is active.
Step 2: Apply to multiple 'SAVE_ITEM' actions
Only the first save call runs; subsequent actions during that time are ignored until it completes.
Final Answer:
Only the first save runs; others are ignored until it completes -> Option A
Quick Check:
exhaustMap ignores new emissions during active inner observable [OK]

Quick Trick: exhaustMap ignores new actions until current completes [OK]

Common Mistakes:

Confusing exhaustMap with switchMap or mergeMap
Expecting all saves to run concurrently

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More Angular Quizzes

Consider this effect:

Step 1: Understand exhaustMap behavior

Step 2: Apply to multiple 'SAVE_ITEM' actions

Final Answer:

Quick Check:

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