From ba31e9ed2631c3b319fb6ab2d4a302700bfcff0d Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Thu, 10 Nov 2022 22:54:16 +0800
Subject: [PATCH] feat(pages): routes HMR

---
 packages/nuxt/src/pages/module.ts         | 12 +++++++++++-
 packages/nuxt/src/pages/runtime/router.ts | 15 ++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/packages/nuxt/src/pages/module.ts b/packages/nuxt/src/pages/module.ts
index d9ec94af32c0..ea84da6effc2 100644
--- a/packages/nuxt/src/pages/module.ts
+++ b/packages/nuxt/src/pages/module.ts
@@ -167,7 +167,17 @@ export default defineNuxtModule({
         const pages = await resolvePagesRoutes()
         await nuxt.callHook('pages:extend', pages)
         const { routes, imports } = normalizeRoutes(pages)
-        return [...imports, `export default ${routes}`].join('\n')
+        return [
+          ...imports,
+          `export default ${routes}`,
+          'export function onUpdate(fn) { onUpdate._fn = fn }',
+          'if (import.meta.hot) {',
+          '  import.meta.hot.accept((mod) => {',
+          '    onUpdate._fn?.(mod.default)',
+          '    mod.onUpdate._fn = onUpdate._fn',
+          '  })',
+          '}'
+        ].join('\n')
       }
     })
 
diff --git a/packages/nuxt/src/pages/runtime/router.ts b/packages/nuxt/src/pages/runtime/router.ts
index 662b8073bf4c..61829e5c26bd 100644
--- a/packages/nuxt/src/pages/runtime/router.ts
+++ b/packages/nuxt/src/pages/runtime/router.ts
@@ -67,10 +67,23 @@ export default defineNuxtPlugin(async (nuxtApp) => {
   const router = createRouter({
     ...routerOptions,
     history,
-    routes
+    routes: []
   })
+  let clearRoutes = router.addRoute({ path: '', children: routes })
   nuxtApp.vueApp.use(router)
 
+  // Routes HMR
+  if (import.meta.hot) {
+    // @ts-expect-error
+    import('#build/routes').then(({ onUpdate }) => {
+      onUpdate((newRoutes: any) => {
+        const routes = routerOptions.routes?.(newRoutes) ?? newRoutes
+        clearRoutes()
+        clearRoutes = router.addRoute({ path: '', children: routes })
+      })
+    })
+  }
+
   const previousRoute = shallowRef(router.currentRoute.value)
   router.afterEach((_to, from) => {
     previousRoute.value = from