feat(nuxi): cli wrapper for self restart (#18641)

docs/3.api/4.advanced/1.hooks.md

@@ -38,7 +38,7 @@ Hook                     | Arguments                  | Description
 `kit:compatibility`      | `compatibility, issues`    | Allows extending compatibility checks.
 `ready`                  | `nuxt`                     | Called after Nuxt initialization, when the Nuxt instance is ready to work.
 `close`                  | `nuxt`                     | Called when Nuxt instance is gracefully closing.
-`restart`                | -                          | Called to restart the current Nuxt instance. **This hook is currently only available on the [Edge Channel](/docs/guide/going-further/edge-channel/).** <!-- stabilityedge -->
+`restart`                | `{ hard?: boolean }`       | To be called to restart the current Nuxt instance. **This hook is currently only available on the [Edge Channel](/docs/guide/going-further/edge-channel/).** <!-- stabilityedge -->
 `modules:before`         | -                          | Called during Nuxt initialization, before installing user modules.
 `modules:done`           | -                          | Called during Nuxt initialization, after installing user modules.
 `app:resolve`            | `app`                      | Called after resolving the `app` instance.

packages/nuxi/bin/nuxi.mjs

@@ -1,3 +1,2 @@
 #!/usr/bin/env node
-process._startTime = Date.now()
-import('../dist/cli.mjs').then(r => (r.default || r).main())
+import('../dist/cli-wrapper.mjs')

packages/nuxi/build.config.ts

@@ -10,6 +10,8 @@ export default defineBuildConfig({
   },
   entries: [
     'src/cli',
+    'src/cli-run',
+    'src/cli-wrapper',
     'src/index'
   ],
   externals: [

packages/nuxi/src/cli-run.ts

@@ -0,0 +1,4 @@
+// @ts-ignore
+process._startTime = Date.now()
+// @ts-ignore
+import('./cli').then(r => (r.default || r).main())

packages/nuxi/src/cli-wrapper.ts

@@ -0,0 +1,40 @@
+/**
+ * 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'
+
+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') {
+  await startSubprocess([], args)
+} else {
+  await import(cliEntry)
+}

packages/nuxi/src/commands/dev.ts

@@ -14,6 +14,7 @@ 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({
@@ -89,6 +90,14 @@ 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))
 
         if (!isRestart) {

packages/nuxi/src/constants.ts

@@ -0,0 +1,11 @@
+/**
+ * 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 +1,2 @@
 export * from './run'
+export * from './constants'

packages/schema/src/types/hooks.ts

@@ -77,7 +77,12 @@ export interface NuxtHooks {
    * Called to restart the current Nuxt instance.
    * @returns Promise
    */
-  'restart': () => HookResult
+  'restart': (options?: {
+    /**
+     * Try to restart the whole process if supported
+     */
+    hard?: boolean
+  }) => HookResult
 
   /**
    * Called during Nuxt initialization, before installing user modules.