Vue JS Vue JS State Management 3

Question 1

How do you subscribe to state changes in Pinia to run a side effect after every mutation?

Accepted Answer

store.$subscribe()

Answer

$subscribe() registers a callback that fires after every state change in the store, providing the mutation and the new state.

Question 2

What is the Composition API style of defining a Pinia store?

Accepted Answer

Using defineStore() with a setup function that returns reactive state and methods

Answer

The setup store syntax passes a setup function to defineStore() where you use ref(), computed(), and plain functions, then return everything to expose.

Question 3

How can Pinia store actions be tested in isolation without mounting a Vue component?

Accepted Answer

Create a Pinia instance with createPinia(), install it with setActivePinia(), then call the store composable directly

Answer

setActivePinia(createPinia()) sets up a fresh Pinia context so you can instantiate and test stores directly in Jest/Vitest without a Vue app.

Question 4

What Vuex plugin feature allows you to intercept every mutation to implement logging or persistence?

Accepted Answer

plugins array in createStore() with a subscribe-based function

Answer

Vuex plugins are functions added to the plugins array in createStore() that receive the store and call store.subscribe() to react to every mutation.

Question 5

In Pinia, how do you reset a store's state to its initial values?

Accepted Answer

store.$reset()

Answer

$reset() is a built-in Pinia method available on Options-API stores that reverts all state properties back to their initial values.

Vue JS Practice Test

Vue JS Practice Test

Vue JS Vue JS State Management 3