breaking: drop fully preserve modifier codes on v-t directive

docs/guide/migration/breaking.md

@@ -314,7 +314,6 @@ console.log(VueI18n.availability)
 
 > [!CAUTION]
 > `preserveDirectiveContent` option implementation code is be going to fully remove in v10.
-> As an alternative.
 
 The `v-t` directive for Vue 3 now preserves the default content. Therefore, this option and its properties have been removed from the VueI18n instance.
 
@@ -420,6 +419,9 @@ const messages = {
 
 ### Remove `preserve` modifier
 
+> [!CAUTION]
+> `preserve` modifier implementation code is be going to fully remove in v10.
+
 Similar to *[Remove `preserveDirectiveContent` option](#remove-preservedirectivecontent-option)*, the `v-t` directive for Vue 3 now preserves the default content. Therefore, `preserve` modifier and it’s have been removed from `v-t` directive.
 
 Vue I18n v8.x:

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

@@ -1,13 +1,6 @@
 import { watch } from 'vue'
-import { I18nWarnCodes, getWarnMessage } from './warnings'
 import { createI18nError, I18nErrorCodes } from './errors'
-import {
- isString,
- isPlainObject,
- isNumber,
- warn,
- inBrowser
-} from '@intlify/shared'
+import { isString, isPlainObject, isNumber, inBrowser } from '@intlify/shared'
 
 import type {
  DirectiveBinding,
@@ -89,16 +82,13 @@ export type TranslationDirective<T = HTMLElement> = ObjectDirective<T>
 
 export function vTDirective(i18n: I18n): TranslationDirective<HTMLElement> {
  const _process = (binding: DirectiveBinding): [string, Composer] => {
- const { instance, modifiers, value } = binding
+ const { instance, value } = binding
  /* istanbul ignore if */
  if (!instance || !instance.$) {
  throw createI18nError(I18nErrorCodes.UNEXPECTED_ERROR)
  }
 
  const composer = getComposer(i18n, instance.$)
- if (__DEV__ && modifiers.preserve) {
- warn(getWarnMessage(I18nWarnCodes.NOT_SUPPORTED_PRESERVE))
- }
 
  const parsedValue = parseValue(value)
  return [

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

@@ -6,19 +6,17 @@ const inc = incrementer(code)
 
 export const I18nWarnCodes = {
  FALLBACK_TO_ROOT: code, // 8
- NOT_SUPPORTED_PRESERVE: inc(), // 9
- NOT_SUPPORTED_GET_CHOICE_INDEX: inc(), // 10
- COMPONENT_NAME_LEGACY_COMPATIBLE: inc(), // 11
- NOT_FOUND_PARENT_SCOPE: inc(), // 12
- IGNORE_OBJ_FLATTEN: inc(), // 13
- NOTICE_DROP_TRANSLATE_EXIST_COMPATIBLE_FLAG: inc() // 14
+ NOT_SUPPORTED_GET_CHOICE_INDEX: inc(), // 9
+ COMPONENT_NAME_LEGACY_COMPATIBLE: inc(), // 10
+ NOT_FOUND_PARENT_SCOPE: inc(), // 11
+ IGNORE_OBJ_FLATTEN: inc(), // 12
+ NOTICE_DROP_TRANSLATE_EXIST_COMPATIBLE_FLAG: inc() // 13
 } as const
 
 type I18nWarnCodes = (typeof I18nWarnCodes)[keyof typeof I18nWarnCodes]
 
 export const warnMessages: { [code: number]: string } = {
  [I18nWarnCodes.FALLBACK_TO_ROOT]: `Fall back to {type} '{key}' with root locale.`,
- [I18nWarnCodes.NOT_SUPPORTED_PRESERVE]: `Not supported 'preserve'.`,
  [I18nWarnCodes.NOT_SUPPORTED_GET_CHOICE_INDEX]: `Not supported 'getChoiceIndex'.`,
  [I18nWarnCodes.COMPONENT_NAME_LEGACY_COMPATIBLE]: `Component name legacy compatible: '{name}' -> 'i18n'`,
  [I18nWarnCodes.NOT_FOUND_PARENT_SCOPE]: `Not found parent scope. use the global scope.`,

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

@@ -141,36 +141,6 @@ test('plural', async () => {
  expect(wrapper.html()).toEqual('<p>2 bananas</p>')
 })
 
-test('preserve modifier', async () => {
- const mockWarn = vi.spyOn(shared, 'warn')
- mockWarn.mockImplementation(() => {})
-
- const i18n = createI18n({
- locale: 'en',
- messages: {
- en: {
- hello: 'hello!'
- }
- }
- })
-
- const App = defineComponent({
- setup() {
- // <p v-t.preserve="'hello'"></p>
- const t = resolveDirective('t')
- return () => {
- return withDirectives(h('p'), [[t!, 'hello', '', { preserve: true }]])
- }
- }
- })
- await mount(App, i18n)
-
- expect(mockWarn).toHaveBeenCalledTimes(1)
- expect(mockWarn.mock.calls[0][0]).toEqual(
- getWarnMessage(I18nWarnCodes.NOT_SUPPORTED_PRESERVE)
- )
-})
-
 test('legacy mode', async () => {
  const i18n = createI18n({
  legacy: true,