fix: exntending for Composer and VueI18n (#1237)

* fix: exntending for Composer and VueI18n

* fix: lint warnings

packages/vue-i18n-core/src/i18n.ts

@@ -240,6 +240,14 @@ export interface I18n<
   dispose(): void
 }
 
+/**
+ * @internal
+ */
+type ExtendHooks = {
+  __composerExtend?: (composer: Composer) => void
+  __vueI18nExtend?: (vueI18n: VueI18n) => void
+}
+
 /**
  * I18n interface for internal usage
  *
@@ -272,6 +280,8 @@ export interface I18nInternal<
     instance: Instance
   ): void
   __deleteInstance(component: ComponentInternalInstance): void
+  __composerExtend?: Required<ExtendHooks>['__composerExtend']
+  __vueI18nExtend?: Required<ExtendHooks>['__vueI18nExtend']
 }
 
 /**
@@ -541,6 +551,15 @@ export function createI18n(options: any = {}, VueI18nLegacy?: any): any {
         app.__VUE_I18N_SYMBOL__ = symbol
         app.provide(app.__VUE_I18N_SYMBOL__, i18n as unknown as I18n)
 
+        // set composer & vuei18n extend hook options from plugin options
+        if (isPlainObject(options[0])) {
+          const opts = options[0] as ExtendHooks
+          ;(i18n as unknown as I18nInternal).__composerExtend =
+            opts.__composerExtend
+          ;(i18n as unknown as I18nInternal).__vueI18nExtend =
+            opts.__vueI18nExtend
+        }
+
         // global method and properties injection for Composition API
         if (!__legacyMode && __globalInjection) {
           injectGlobalFields(app, i18n.global as Composer)
@@ -838,6 +857,9 @@ export function useI18n<
     }
 
     composer = createComposer(composerOptions, _legacyVueI18n) as Composer
+    if (i18nInternal.__composerExtend) {
+      i18nInternal.__composerExtend(composer)
+    }
     setupLifeCycle(i18nInternal, instance, composer)
 
     i18nInternal.__setInstance(instance, composer)

packages/vue-i18n-core/src/mixins/next.ts

@@ -97,6 +97,11 @@ export function defineMixin(
         this.$i18n.n(...args)
       this.$tm = (key: Path): LocaleMessageValue<VueMessageType> | {} =>
         this.$i18n.tm(key)
+
+      // extend vue-i18n legacy APIs
+      if (i18n.__vueI18nExtend) {
+        i18n.__vueI18nExtend(this.$i18n)
+      }
     },
 
     mounted(): void {

packages/vue-i18n-core/test/helper.ts

@@ -15,14 +15,17 @@ import {
 import { compile } from '@vue/compiler-dom'
 import * as runtimeDom from 'vue'
 import { I18n } from '../src/i18n'
-import { isBoolean, assign } from '@intlify/shared'
+import { isBoolean, isPlainObject, assign } from '@intlify/shared'
+
+import type { I18nPluginOptions } from '../src/plugin/types'
 
 export interface MountOptions {
   propsData: Record<string, any> // eslint-disable-line @typescript-eslint/no-explicit-any
   provide: Record<string | symbol, any> // eslint-disable-line @typescript-eslint/no-explicit-any
   components: ComponentOptions['components']
   slots: Record<string, string>
   installI18n: boolean
+  pluginOptions?: I18nPluginOptions
 }
 
 interface Wrapper {
@@ -85,6 +88,20 @@ export function mount(
   const installI18n = isBoolean(options.installI18n)
     ? options.installI18n
     : true
+
+  const pluginOptions: I18nPluginOptions = isPlainObject(options.pluginOptions)
+    ? options.pluginOptions
+    : {
+        globalInstall: true,
+        useI18nComponentName: false
+      }
+  if (pluginOptions.globalInstall == null) {
+    pluginOptions.globalInstall = true
+  }
+  if (pluginOptions.useI18nComponentName == null) {
+    pluginOptions.useI18nComponentName = false
+  }
+
   return new Promise((resolve, reject) => {
     // NOTE: only supports props as an object
     const propsData = reactive(
@@ -156,7 +173,7 @@ export function mount(
       }
     }
 
-    installI18n && app.use(i18n)
+    installI18n && app.use(i18n, pluginOptions)
 
     const rootEl = document.createElement('div')
     document.body.appendChild(rootEl)

packages/vue-i18n-core/test/i18n.test.ts

@@ -4,6 +4,7 @@
 
 import {
   h,
+  ref,
   defineComponent,
   defineCustomElement,
   nextTick,
@@ -32,6 +33,7 @@ import {
 } from '@intlify/devtools-if'
 
 import type { I18n } from '../src/i18n'
+import type { VueI18n } from '../src/legacy'
 import type { App } from 'vue'
 
 const container = document.createElement('div')
@@ -1360,3 +1362,58 @@ describe('release global scope', () => {
     expect(error).not.toEqual(errorMessages[I18nErrorCodes.UNEXPECTED_ERROR])
   })
 })
+
+describe('Composer & VueI18n extend hooking', () => {
+  test('composition', async () => {
+    const composerExtendSpy = jest
+      .fn()
+      .mockImplementation((composer: Composer) => {
+        ;(composer as any).foo = ref('hello world')
+      })
+    const vueI18nExtendSpy = jest.fn()
+    const i18n = createI18n({
+      legacy: false
+    })
+
+    const App = defineComponent({
+      setup() {
+        // @ts-ignore
+        const { foo } = useI18n({
+          useScope: 'local'
+        })
+        return { foo }
+      },
+      template: '<p>{{ foo }}</p>'
+    })
+    const { html } = await mount(App, i18n, {
+      pluginOptions: {
+        __composerExtend: composerExtendSpy,
+        __vueI18nExtend: vueI18nExtendSpy
+      } as any
+    })
+    expect(composerExtendSpy).toHaveBeenCalled()
+    expect(html()).toBe('<p>hello world</p>')
+    expect(vueI18nExtendSpy).not.toHaveBeenCalled()
+  })
+
+  test('legacy', async () => {
+    const composerExtendSpy = jest.fn()
+    const vueI18nExtendSpy = jest
+      .fn()
+      .mockImplementation((vueI18n: VueI18n) => {
+        ;(vueI18n as any).foo = 'hello world'
+      })
+    const i18n = createI18n({ legacy: true })
+
+    const App = defineComponent({ template: '<p>{{ $i18n.foo }}</p>' })
+    const { html } = await mount(App, i18n, {
+      pluginOptions: {
+        __composerExtend: composerExtendSpy,
+        __vueI18nExtend: vueI18nExtendSpy
+      } as any
+    })
+    expect(composerExtendSpy).not.toHaveBeenCalled()
+    expect(vueI18nExtendSpy).toHaveBeenCalled()
+    expect(html()).toBe('<p>hello world</p>')
+  })
+})