Testing component with createTestingPinia results in TypeError: Cannot read properties of undefined (reading '_s')

[awacode21]

Hi guys, when following exactly these instructions: https://pinia.vuejs.org/cookbook/testing.html#unit-testing-components

i always get the following:

TypeError: Cannot read properties of undefined (reading '_s')
    at Module.useStore (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/pinia/dist/pinia.prod.cjs:527:20)
    at setup (/Users/awacode/code/customers/enbw/EKP-Frontend/src/components/TheServiceSheet/TheServiceSheet.vue:20:53)
    at callWithErrorHandling (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:119:22)
    at setupStatefulComponent (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:5789:29)
    at setupComponent (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:5770:11)
    at mountComponent (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4303:13)
    at processComponent (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4288:17)
    at patch (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:3933:21)
    at ReactiveEffect.componentUpdateFn [as fn] (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4381:21)
    at ReactiveEffect.run (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/reactivity/dist/reactivity.cjs.prod.js:178:25)
    at instance.update (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4460:56)
    at setupRenderEffect (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4465:9)
    at mountComponent (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4317:9)
    at processComponent (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4288:17)
    at patch (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:3933:21)
    at render (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:4943:13)
    at mount (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-core/dist/runtime-core.cjs.prod.js:3434:25)
    at Object.app.mount (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/runtime-dom/dist/runtime-dom.cjs.prod.js:1501:23)
    at Module.mount (file:///Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:8264:18)
    at /Users/awacode/code/customers/enbw/EKP-Frontend/tests/unit/ServiceSheet.spec.ts:41:37
    at async runTest (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/chunk-runtime-error.2723946b.mjs:540:7)
    at async runSuite (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/chunk-runtime-error.2723946b.mjs:635:15)
    at async runSuite (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/chunk-runtime-error.2723946b.mjs:635:15)
    at async runFiles (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/chunk-runtime-error.2723946b.mjs:765:5)
    at async startTestsNode (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/chunk-runtime-error.2723946b.mjs:783:3)
    at async /Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/entry.mjs:83:9
    at async Module.withEnv (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/chunk-runtime-error.2723946b.mjs:293:5)
    at async run (/Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/dist/entry.mjs:76:5)
    at async file:///Users/awacode/code/customers/enbw/EKP-Frontend/node_modules/vitest/node_modules/tinypool/dist/esm/worker.js:109:20

i don't get this when i use setActivePinia instead:

const pinia = createTestingPinia({ stubActions: false });
setActivePinia(pinia);
const serviceSheetStore = useServiceSheetStore();

any idea why i get this error when following the instructions for testing a component?

[posva]

that setActivePinia() is indeed necessary as shown in the examples at https://pinia.vuejs.org/cookbook/testing.html#unit-testing-a-store. Without an active pinia, stores cannot be used if there isn't an active pinia

[awacode21]

Shouldn't this then also be part of the example for "Unit testing components"?

[posva]

It could be added as a note: it’s necessary if you need to call the useStore() before mounting (which internally calls the method)
Well worth a PR! 🙂