From a21d8654ac258289fcc44e9dfbb84e90fee63111 Mon Sep 17 00:00:00 2001
From: kazuya kawaguchi <kawakazu80@gmail.com>
Date: Sun, 20 Apr 2025 12:14:48 +0900
Subject: [PATCH] fix(unpluing-vue-i18n): Support for `transform.handler` in
 vite:json plugin

---
 .../unplugin-vue-i18n/src/core/resource.ts    | 31 ++++++++++++++++---
 .../unplugin-vue-i18n/src/utils/plugin.ts     | 28 +++++++++++++++++
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/packages/unplugin-vue-i18n/src/core/resource.ts b/packages/unplugin-vue-i18n/src/core/resource.ts
index cc22b236..695bd5e7 100644
--- a/packages/unplugin-vue-i18n/src/core/resource.ts
+++ b/packages/unplugin-vue-i18n/src/core/resource.ts
@@ -14,7 +14,16 @@ import { createHash } from 'node:crypto'
 import fs from 'node:fs'
 import { dirname, parse as parsePath, resolve } from 'node:path'
 import { parse } from 'vue/compiler-sfc'
-import { checkVuePlugin, error, getVitePlugin, raiseError, resolveNamespace, warn } from '../utils'
+import {
+  checkVuePlugin,
+  error,
+  getVitePlugin,
+  getVitePluginTransform,
+  overrideVitePluginTransform,
+  raiseError,
+  resolveNamespace,
+  warn
+} from '../utils'
 import { getVueCompiler, parseVueRequest } from '../vue'
 
 import type { CodeGenOptions } from '@intlify/bundle-utils'
@@ -168,12 +177,23 @@ export function resourcePlugin(opts: ResolvedOptions, meta: UnpluginContextMeta)
         ctx.sourceMap = config.command === 'build' ? !!config.build.sourcemap : false
         debug(`configResolved: isProduction = ${ctx.prod}, sourceMap = ${ctx.sourceMap}`)
 
+        /**
+         * NOTE:
+         * For the native rolldown plugin, we need to change to another solution from the current workaround.
+         * Currently, the rolldown team and vite team are discussing this issue.
+         * https://github.com/vitejs/rolldown-vite/issues/120
+         */
+
         // json transform handling
         const jsonPlugin = getVitePlugin(config, 'vite:json')
         if (jsonPlugin) {
-          // backup @rollup/plugin-json
-          const orgTransform = jsonPlugin.transform
-          jsonPlugin.transform = async function (code: string, id: string) {
+          // saving `vite:json` plugin instance
+          const [orgTransform, transformWay] = getVitePluginTransform(jsonPlugin)
+          if (!orgTransform) {
+            throw new Error('vite:json plugin not found!')
+          }
+
+          async function overrideViteJsonPlugin(code: string, id: string) {
             if (!/\.json$/.test(id) || filter(id)) {
               return
             }
@@ -195,6 +215,9 @@ export function resourcePlugin(opts: ResolvedOptions, meta: UnpluginContextMeta)
             // @ts-expect-error
             return orgTransform!.apply(this, [code, id])
           }
+
+          // override `vite:json` plugin transform function
+          overrideVitePluginTransform(jsonPlugin, overrideViteJsonPlugin, transformWay!)
         }
       }
     },
diff --git a/packages/unplugin-vue-i18n/src/utils/plugin.ts b/packages/unplugin-vue-i18n/src/utils/plugin.ts
index d8004c30..74937801 100644
--- a/packages/unplugin-vue-i18n/src/utils/plugin.ts
+++ b/packages/unplugin-vue-i18n/src/utils/plugin.ts
@@ -15,6 +15,34 @@ export function getVitePlugin(config: UserConfig, name: string): RollupPlugin |
   return config.plugins.find(p => p.name === name) as RollupPlugin
 }
 
+export function getVitePluginTransform(
+  plugin: RollupPlugin
+): [RollupPlugin['transform'], 'handler' | 'transform' | undefined] {
+  if (plugin.transform) {
+    return 'handler' in plugin.transform
+      ? [plugin.transform.handler, 'handler']
+      : [plugin.transform, 'transform']
+  } else {
+    return [undefined, undefined]
+  }
+}
+
+// TODO: `override` type, we need more strict type
+export function overrideVitePluginTransform(
+  plugin: RollupPlugin,
+  override: Function,
+  to: 'handler' | 'transform'
+): void {
+  if (plugin.transform == undefined) {
+    throw new Error('plugin.transform is undefined')
+  }
+  if (to === 'handler' && 'handler' in plugin.transform) {
+    plugin.transform.handler = override as typeof plugin.transform.handler
+  } else {
+    plugin.transform = override as typeof plugin.transform
+  }
+}
+
 export function checkVuePlugin(vuePlugin: RollupPlugin | null): boolean {
   if (vuePlugin == null || !vuePlugin.api) {
     error(