refactor(nuxi): hard restart with communication channel (#19423)

packages/nuxi/src/cli-run.ts

@@ -1,4 +1,5 @@
 // @ts-ignore
 process._startTime = Date.now()
+
 // @ts-ignore
 import('./cli').then(r => (r.default || r).main())

packages/nuxi/src/cli-wrapper.ts

@@ -2,39 +2,38 @@
  * This file is used to wrap the CLI entrypoint in a restartable process.
  */
 import { fileURLToPath } from 'node:url'
-import { execa } from 'execa'
-import { EXIT_CODE_RESTART } from './constants'
+import { fork } from 'node:child_process'
+import type { ChildProcess } from 'node:child_process'
 
 const cliEntry = fileURLToPath(new URL('../dist/cli-run.mjs', import.meta.url))
 
-async function startSubprocess (preArgs: string[], postArgs: string[]) {
-  const child = await execa(
-    'node',
-    [
-      ...preArgs,
-      cliEntry,
-      ...postArgs
-    ],
-    {
-      reject: false,
-      stdio: 'inherit',
-      env: {
-        ...process.env,
-        NUXI_CLI_WRAPPER: 'true'
-      }
-    }
-  )
-  if (child.exitCode === EXIT_CODE_RESTART) {
-    await startSubprocess(preArgs, postArgs)
-  } else {
-    process.exit(child.exitCode)
-  }
-}
-
-const args = process.argv.slice(2)
-// only enable wrapper in dev command
-if (args[0] === 'dev') {
-  startSubprocess([], args)
+// Only enable wrapper for nuxt dev command
+if (process.argv[2] === 'dev') {
+  process.env.__CLI_ARGV__ = JSON.stringify(process.argv)
+  startSubprocess()
 } else {
   import(cliEntry)
 }
+
+function startSubprocess () {
+  let childProc: ChildProcess
+
+  process.on('exit', () => {
+    if (childProc) {
+      childProc.kill()
+    }
+  })
+
+  start()
+
+  function start () {
+    childProc = fork(cliEntry)
+    childProc.on('close', (code) => { if (code) { process.exit(code) } })
+    childProc.on('message', (message) => {
+      if ((message as { type: string })?.type === 'nuxt:restart') {
+        childProc.kill()
+        startSubprocess()
+      }
+    })
+  }
+}

packages/nuxi/src/cli.ts

@@ -9,7 +9,7 @@ import { showHelp } from './utils/help'
 import { showBanner } from './utils/banner'
 
 async function _main () {
-  const _argv = process.argv.slice(2)
+  const _argv = (process.env.__CLI_ARGV__ ? JSON.parse(process.env.__CLI_ARGV__) : process.argv).slice(2)
   const args = mri(_argv, {
     boolean: [
       'no-clear'

packages/nuxi/src/commands/dev.ts

@@ -14,7 +14,6 @@ import { loadKit } from '../utils/kit'
 import { importModule } from '../utils/cjs'
 import { overrideEnv } from '../utils/env'
 import { writeNuxtManifest, loadNuxtManifest, cleanupNuxtDirs } from '../utils/nuxt'
-import { EXIT_CODE_RESTART } from '../constants'
 import { defineNuxtCommand } from './index'
 
 export default defineNuxtCommand({
@@ -90,15 +89,18 @@ export default defineNuxtCommand({
         }
 
         currentNuxt = await loadNuxt({ rootDir, dev: true, ready: false })
-        // Hard restart
-        if (process.env.NUXI_CLI_WRAPPER) {
-          currentNuxt.hooks.hook('restart', (options) => {
-            if (options?.hard) {
-              process.exit(EXIT_CODE_RESTART)
-            }
-          })
-        }
-        currentNuxt.hooks.hookOnce('restart', () => load(true))
+
+        currentNuxt.hooks.hookOnce('restart', async (options) => {
+          if (options?.hard && process.send) {
+            await listener.close().catch(() => {})
+            await currentNuxt.close().catch(() => {})
+            await watcher.close().catch(() => {})
+            await distWatcher.close().catch(() => {})
+            process.send({ type: 'nuxt:restart' })
+          } else {
+            await load(true)
+          }
+        })
 
         if (!isRestart) {
           showURL()
@@ -121,7 +123,7 @@ export default defineNuxtCommand({
         await currentNuxt.ready()
 
         await currentNuxt.hooks.callHook('listen', listener.server, listener)
-        const address = listener.server.address() as AddressInfo
+        const address = (listener.server.address() || {}) as AddressInfo
         currentNuxt.options.devServer.url = listener.url
         currentNuxt.options.devServer.port = address.port
         currentNuxt.options.devServer.host = address.address

packages/nuxi/src/constants.ts

@@ -1,11 +0,0 @@
-/**
- * Special exit code to restart the process
- *
- * Usage:
- * ```ts
- * if (process.env.NUXI_CLI_WRAPPER) {
- *   process.exit(EXIT_CODE_RESTART)
- * }
- * ```
- */
-export const EXIT_CODE_RESTART = 85

packages/nuxi/src/index.ts

@@ -1,2 +1 @@
 export * from './run'
-export * from './constants'