Vue Comonpent test using cypress, getActivePinia was called with no active Pinia

[steelONIONknight]

Here are my code snippets:

Test.vue

<template>
  <button v-show="store.common == 'hi'" @click="func">
    hello world
  </button>
</template>

<script setup>
import {mainStore} from './index.js'
import {check} from './check.js'

function func() {
  check();
}

</script>

check.js

import {mainStore} from './index.js'

// need define this store here in project.
// In check.js, many functions use a same store. 
// If i don't use mainStore() at the top of a module, the Test.vue can't be rendered.
let store = mainStore();

function check() {
// store may be updated, for example from backend.
  store.common = 'hello';
}

export {check};

index.js

import {defineStore} from "pinia"

export const mainStore = defineStore('main', {
  state: () => {
    return {
      common: 'hi', 
    }
  },
  getters: {}, 
  actions: {}, 
})

My test file, temp.cy.js

import {mount} from 'cypress/vue'
import { createApp } from 'vue'
import Test from './Test.vue'
import {createPinia, setActivePinia} from "pinia"

describe('for example', () => {
  const app = createApp({});
  beforeEach(() => {
    const pinia = createPinia();
    app.use(pinia);
    setActivePinia(pinia);
  });
  
  it('render', () => {
    mount(Test);
  });
})

When I ran this test, I'll get a error: getActivePinia was called with no active Pinia.

I tried to change code of check.js to this:

import {mainStore} from './index.js'

// need define this store here in project.
let store = null;

function getStore() {
  if (store === null) {
    store = mainStore();
  }
}

function check() {
  getStore();
  store.common = 'hello';
}

export {check};

or

import {mainStore} from './index.js'
import {onBeforeMount} from 'vue'

// need define this store here in project.
let store = null;

onBeforeMount(() => {
  store = mainStore();
});

function check() {
  store.common = 'hello';
}

export {check};

and then component cannot be rendered, get error: Cannot read properties of undefined (reading common)
How can I fix this problem? what's wrong with my code?

[posva]

You cannot call the useStore() method anywhere, See https://pinia.vuejs.org/core-concepts/outside-component-usage.html