feat: Part options support $n

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

@@ -1209,7 +1209,7 @@ export interface ComposerNumberFormatting<
       | Key
       | ResourceKeys
       | NumberOptions<Key | ResourceKeys, Locales>
-  ): string
+  ): string | Intl.NumberFormatPart[]
   /**
    * Number Formatting
    *
@@ -1231,7 +1231,7 @@ export interface ComposerNumberFormatting<
       | ResourceKeys
       | NumberOptions<Key | ResourceKeys, Locales>,
     locale: Locales
-  ): string
+  ): string | Intl.NumberFormatPart[]
 }
 
 /**
@@ -2287,14 +2287,17 @@ export function createComposer(options: any = {}): any {
   }
 
   // n
-  function n(...args: unknown[]): string {
-    return wrapWithDeps<{}, string>(
-      context => Reflect.apply(number, null, [context, ...args]) as string,
+  function n(...args: unknown[]): string | Intl.NumberFormatPart[] {
+    return wrapWithDeps<{}, string | Intl.NumberFormatPart[]>(
+      context =>
+        Reflect.apply(number, null, [context, ...args]) as
+          | string
+          | Intl.NumberFormatPart[],
       () => parseNumberArgs(...args),
       'number format',
       root => Reflect.apply(root.n, root, [...args]),
       () => MISSING_RESOLVE_VALUE,
-      val => isString(val)
+      val => isString(val) || isArray(val)
     )
   }
 

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

@@ -353,15 +353,15 @@ test('strict composer with direct options', () => {
     strictDirectComposer.d(new Date(), 'custom' as any)
   ).toEqualTypeOf<string>()
   expectTypeOf(strictDirectComposer.n(1)).toEqualTypeOf<string>()
-  expectTypeOf(
-    strictDirectComposer.n(1, 'currency', 'zh')
-  ).toEqualTypeOf<string>()
+  expectTypeOf(strictDirectComposer.n(1, 'currency', 'zh')).toEqualTypeOf<
+    string | Intl.NumberFormatPart[]
+  >()
   expectTypeOf(
     strictDirectComposer.n(1, { key: 'currency', locale: 'en' })
-  ).toEqualTypeOf<string>()
-  expectTypeOf(
-    strictDirectComposer.n(1, 'custom' as any)
-  ).toEqualTypeOf<string>()
+  ).toEqualTypeOf<string | Intl.NumberFormatPart[]>()
+  expectTypeOf(strictDirectComposer.n(1, 'custom' as any)).toEqualTypeOf<
+    string | Intl.NumberFormatPart[]
+  >()
 
   // const noOptionsComposer = createComposer({ missingWarn: true })
   const noOptionsComposer = createComposer({ locale: 'en' })

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

@@ -5,41 +5,41 @@
 
 // utils
 import * as shared from '@intlify/shared'
+import { pluralRules as _pluralRules } from './helper'
 vi.mock('@intlify/shared', async () => {
   const actual = await vi.importActual<object>('@intlify/shared')
   return {
     ...actual,
     warn: vi.fn()
   }
 })
-import { pluralRules as _pluralRules } from './helper'
 
 import {
+  compile,
+  fallbackWithLocaleChain,
+  Locale,
+  MessageContext,
+  MessageFunction,
+  Path,
+  PathValue,
+  registerLocaleFallbacker,
+  registerMessageCompiler,
+  registerMessageResolver,
+  resolveValue
+} from '@intlify/core-base'
+import { createVNode, nextTick, Text, watch, watchEffect } from 'vue'
+import {
+  ComposerOptions,
   createComposer,
   MissingHandler,
-  ComposerOptions,
   VueMessageType
 } from '../src/composer'
 import {
-  TranslateVNodeSymbol,
+  DatetimePartsSymbol,
   NumberPartsSymbol,
-  DatetimePartsSymbol
+  TranslateVNodeSymbol
 } from '../src/symbols'
 import { getWarnMessage, I18nWarnCodes } from '../src/warnings'
-import { watch, watchEffect, nextTick, Text, createVNode } from 'vue'
-import {
-  Locale,
-  compile,
-  registerMessageCompiler,
-  resolveValue,
-  registerMessageResolver,
-  fallbackWithLocaleChain,
-  registerLocaleFallbacker,
-  MessageContext,
-  Path,
-  PathValue,
-  MessageFunction
-} from '@intlify/core-base'
 
 beforeEach(() => {
   registerMessageCompiler(compile)
@@ -1202,6 +1202,79 @@ describe('n', () => {
     })
     expect(n(0.99, { key: 'percent' })).toEqual('')
   })
+
+  test('part formatting with n', () => {
+    const { n } = createComposer({
+      locale: 'en-US',
+      fallbackLocale: ['ja-JP'],
+      numberFormats: {
+        'en-US': {
+          currency: {
+            style: 'currency',
+            currency: 'USD',
+            currencyDisplay: 'symbol'
+          },
+          decimal: {
+            style: 'decimal',
+            useGrouping: true
+          }
+        },
+        'ja-JP': {
+          currency: {
+            style: 'currency',
+            currency: 'JPY' /*, currencyDisplay: 'symbol'*/
+          },
+          numeric: {
+            style: 'decimal',
+            useGrouping: false
+          },
+          percent: {
+            style: 'percent',
+            useGrouping: true
+          }
+        }
+      }
+    })
+    expect(n(0.99, { key: 'currency', part: true })).toEqual([
+      { type: 'currency', value: '$' },
+      { type: 'integer', value: '0' },
+      { type: 'decimal', value: '.' },
+      { type: 'fraction', value: '99' }
+    ])
+    expect(
+      n(10100, {
+        key: 'currency',
+        locale: 'ja-JP',
+        part: true
+      })
+    ).toEqual([
+      { type: 'currency', value: '￥' },
+      { type: 'integer', value: '10' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '100' }
+    ])
+    expect(n(12145281000, { key: 'percent', part: true })).toEqual([
+      { type: 'integer', value: '1' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '214' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '528' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '100' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '000' },
+      { type: 'percentSign', value: '%' }
+    ])
+    expect(n(12145281111, { key: 'decimal', part: true })).toEqual([
+      { type: 'integer', value: '12' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '145' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '281' },
+      { type: 'group', value: ',' },
+      { type: 'integer', value: '111' }
+    ])
+  })
 })
 
 describe('tm', () => {

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

@@ -865,7 +865,10 @@ declare module 'vue' {
      *
      * @returns formatted value
      */
-    $n(value: number, options: NumberOptions): string
+    $n<OptionsType extends NumberOptions>(
+      value: number,
+      options: OptionsType
+    ): OptionsType['type'] extends true ? Intl.NumberFormatPart[] : string
     /**
      * Locale messages getter
      *