fix: messages type generation not watching locale files (#3224)

build.config.ts

@@ -2,5 +2,13 @@ import { defineBuildConfig } from 'unbuild'
 
 export default defineBuildConfig({
   entries: ['src/module'],
-  externals: ['node:fs', 'node:url', 'webpack', '@babel/parser', 'unplugin-vue-router', 'unplugin-vue-router/options']
+  externals: [
+    'node:fs',
+    'node:url',
+    'webpack',
+    '@babel/parser',
+    'unplugin-vue-router',
+    'unplugin-vue-router/options',
+    'chokidar'
+  ]
 })

package.json

@@ -120,6 +120,7 @@
     "@unhead/vue": "^1.8.8",
     "bumpp": "^9.4.1",
     "changelogithub": "^0.13.7",
+    "chokidar": "^4.0.1",
     "consola": "^3",
     "eslint": "^9.5.0",
     "eslint-config-prettier": "^9.1.0",

src/prepare/type-generation.ts

@@ -1,5 +1,6 @@
-import { relative, resolve } from 'pathe'
-import { addServerHandler, addTypeTemplate, updateTemplates, useNitro } from '@nuxt/kit'
+import { normalize, relative, resolve } from 'pathe'
+import { addServerHandler, addTypeTemplate, isIgnored, updateTemplates, useNitro } from '@nuxt/kit'
+import { watch as chokidarWatch } from 'chokidar'
 
 import type { Nuxt } from '@nuxt/schema'
 import type { I18nOptions } from 'vue-i18n'
@@ -112,6 +113,22 @@ export {}`
     }
   })
 
+  // setup watcher when using restructureDir - folders outside srcDir are not watched
+  if (nuxt.options.future?.compatibilityVersion === 4 || options.restructureDir === false) {
+    const watcher = chokidarWatch(
+      localeInfo.flatMap(x => x.files.map(f => resolve(nuxt.options.srcDir, f.path))),
+      {
+        awaitWriteFinish: true,
+        ignoreInitial: true,
+        ignored: [isIgnored, 'node_modules']
+      }
+    )
+
+    // eslint-disable-next-line @typescript-eslint/no-misused-promises, @typescript-eslint/no-unsafe-argument
+    watcher.on('all', (event, path) => nuxt.callHook('builder:watch', event, normalize(path)))
+    nuxt.hook('close', () => watcher?.close())
+  }
+
   // watch locale files for changes and update template
   // TODO: consider conditionally checking absolute paths for Nuxt 4
   const localePaths = localeInfo.flatMap(x => x.files.map(f => relative(nuxt.options.srcDir, f.path)))