test: add example test for nuxt-injected value

resolves #539

Co-authored-by: Oskar Olsson <oskar.olsson@backmarket.com>

examples/app-vitest-full/components/InjectedValueComponent.vue

@@ -0,0 +1,11 @@
+<template>
+  <div>
+    {{ value }}
+  </div>
+</template>
+
+<script setup lang="ts">
+import { CUSTOM_VUE_PLUGIN_SYMBOL } from '../plugins/inject-value'
+
+const value = inject(CUSTOM_VUE_PLUGIN_SYMBOL)
+</script>

examples/app-vitest-full/plugins/inject-value.ts

@@ -0,0 +1,13 @@
+export const CUSTOM_VUE_PLUGIN_SYMBOL = Symbol('CUSTOM_VUE_PLUGIN_INJECTED')
+
+export const VUE_INJECTED_VALUE = 'injected vue plugin value'
+
+export default defineNuxtPlugin((nuxtApp) => {
+  const vuePlugin = {
+    install(app: any) {
+      app.provide(CUSTOM_VUE_PLUGIN_SYMBOL, VUE_INJECTED_VALUE)
+    },
+  }
+
+  nuxtApp.vueApp.use(vuePlugin)
+})

examples/app-vitest-full/tests/nuxt/injected-value-component.spec.ts

@@ -0,0 +1,12 @@
+import { describe, expect, it } from 'vitest'
+import { mountSuspended } from '@nuxt/test-utils/runtime'
+
+import { VUE_INJECTED_VALUE } from '~/plugins/inject-value'
+import InjectedValueComponent from '~/components/InjectedValueComponent.vue'
+
+describe('InjectedValueComponent', () => {
+  it('can use injected values from a plugin', async () => {
+    const component = await mountSuspended(InjectedValueComponent)
+    expect(component.text()).toContain(VUE_INJECTED_VALUE)
+  })
+})