fix: move watcher to assembler and send IPC messages for file changes

package.json

@@ -53,7 +53,7 @@
     "cross-env": "^10.1.0",
     "del-cli": "^7.0.0",
     "eslint": "^9.37.0",
-    "hot-hook": "^0.4.1-next.0",
+    "hot-hook": "^0.4.1-next.2",
     "p-event": "^7.0.0",
     "prettier": "^3.6.2",
     "release-it": "^19.0.5",

src/dev_server.ts

@@ -55,15 +55,6 @@ import {
  * await devServer.start(ts)
  */
 export class DevServer {
-  /**
-   * Pre-allocated info object for hot-hook change events to avoid repeated object creation
-   */
-  static readonly #HOT_HOOK_CHANGE_INFO = {
-    source: 'hot-hook' as const,
-    fullReload: false,
-    hotReloaded: false,
-  }
-
   /**
    * Pre-allocated info object for hot-hook full reload events
    */
@@ -119,6 +110,11 @@ export class DevServer {
    */
   #httpServer?: ResultPromise
 
+  /**
+   * Flag to track if the HTTP server child process is alive
+   */
+  #isHttpServerAlive = false
+
   /**
    * Keyboard shortcuts manager instance
    */
@@ -348,6 +344,81 @@ export class DevServer {
     }
   }
 
+  /**
+   * Creates our file system watcher
+   */
+  #createWatcher(options?: { poll?: boolean }) {
+    const watcher = watch({
+      usePolling: options?.poll ?? false,
+      cwd: this.cwdPath,
+      ignoreInitial: true,
+      ignored: (file, stats) => {
+        if (!stats) return false
+        if (file.includes('inertia') && !file.includes('node_modules')) return false
+        if (stats.isFile()) return !this.#fileSystem.shouldWatchFile(file)
+
+        return !this.#fileSystem.shouldWatchDirectory(file)
+      },
+    })
+
+    watcher.on('error', (error: any) => {
+      this.ui.logger.warning('file system watcher failure')
+      this.ui.logger.fatal(error as any)
+
+      this.#onError?.(error)
+      this.#watcher?.close()
+    })
+
+    watcher.on('ready', () => {
+      this.ui.logger.info('watching file system for changes...')
+    })
+
+    return watcher
+  }
+
+  /**
+   * Handles file change events in HMR mode by forwarding to hot-hook
+   * or restarting the server if dead.
+   */
+  #handleHmrWatcherEvent(options: {
+    filePath: string
+    action: 'add' | 'change' | 'unlink'
+    displayLabel: 'add' | 'update' | 'delete'
+  }) {
+    const relativePath = string.toUnixSlash(options.filePath)
+    const absolutePath = join(this.cwdPath, relativePath)
+
+    if (this.#isHttpServerAlive === false) {
+      this.#clearScreen()
+      this.ui.logger.log(`${this.ui.colors.green(options.displayLabel)} ${relativePath}`)
+      this.#restartHTTPServer()
+      return
+    }
+
+    /**
+     * For add/unlink, we call the hooks directly since hot-hook ignores files
+     * not in its dependency tree. This ensures index files are regenerated
+     * for new/removed files.
+     */
+    if (options.action === 'add') {
+      this.#hooks.runner('fileAdded').run(relativePath, absolutePath, this)
+    } else if (options.action === 'unlink') {
+      this.#hooks.runner('fileRemoved').run(relativePath, absolutePath, this)
+    }
+
+    /**
+     * Forward all events to hot-hook so it can:
+     * - Update its dependency tree (for unlink)
+     * - Handle HMR for change events on imported files
+     * - Then we wait for hot-hook to notify us back via IPC message
+     */
+    this.#httpServer?.send({
+      type: 'hot-hook:file-changed',
+      path: absolutePath,
+      action: options.action,
+    })
+  }
+
   /**
    * Handles file change events and triggers appropriate server actions
    *
@@ -627,7 +698,7 @@ export class DevServer {
     await this.#hooks.runner('devServerStarting').run(this)
     debug('starting http server using "%s" file, options %O', this.scriptFile, this.options)
 
-    return new Promise<void>(async (resolve) => {
+    return new Promise<void>((resolve) => {
       /**
        * Creating child process
        */
@@ -638,6 +709,7 @@ export class DevServer {
         reject: true,
         scriptArgs: this.options.scriptArgs,
       })
+      this.#isHttpServerAlive = true
 
       this.#httpServer.on('message', async (message) => {
         if (this.#isAdonisJSReadyMessage(message)) {
@@ -651,20 +723,7 @@ export class DevServer {
         } else if (this.#mode === 'hmr' && this.#isHotHookMessage(message)) {
           debug('received hot-hook message %O', message)
 
-          if (message.type === 'hot-hook:file-changed') {
-            const absolutePath = message.path ? string.toUnixSlash(message.path) : ''
-            const relativePath = relative(this.cwdPath, absolutePath)
-
-            if (message.action === 'add') {
-              this.#hooks.runner('fileAdded').run(relativePath, absolutePath, this)
-            } else if (message.action === 'change') {
-              this.#hooks
-                .runner('fileChanged')
-                .run(relativePath, absolutePath, DevServer.#HOT_HOOK_CHANGE_INFO, this)
-            } else if (message.action === 'unlink') {
-              this.#hooks.runner('fileRemoved').run(relativePath, absolutePath, this)
-            }
-          } else if (message.type === 'hot-hook:full-reload') {
+          if (message.type === 'hot-hook:full-reload') {
             const absolutePath = message.path ? string.toUnixSlash(message.path) : ''
             const relativePath = relative(this.cwdPath, absolutePath)
 
@@ -684,13 +743,15 @@ export class DevServer {
 
       this.#httpServer
         .then((result) => {
+          this.#isHttpServerAlive = false
           if (!this.#watcher) {
             this.#onClose?.(result.exitCode!)
           } else {
             this.ui.logger.info('Underlying HTTP server closed. Still watching for changes')
           }
         })
         .catch((error) => {
+          this.#isHttpServerAlive = false
           if (!this.#watcher) {
             this.#onError?.(error)
           } else {
@@ -783,19 +844,25 @@ export class DevServer {
       this.options.nodeArgs.push('--import=hot-hook/register')
       this.options.env = {
         ...this.options.env,
-        HOT_HOOK_INCLUDE: this.#fileSystem.includes.join(','),
-        HOT_HOOK_IGNORE: this.#fileSystem.excludes
-          .filter((exclude) => !exclude.includes('inertia'))
-          .join(','),
-        HOT_HOOK_RESTART: (this.options.metaFiles ?? [])
-          .filter(({ reloadServer }) => !!reloadServer)
-          .map(({ pattern }) => pattern)
-          .join(','),
+        HOT_HOOK_WATCH: 'false',
       }
     }
 
     this.ui.logger.info('starting HTTP server...')
     await this.#startHTTPServer(this.#stickyPort)
+
+    if (this.#mode !== 'hmr') return
+
+    this.#watcher = this.#createWatcher()
+    this.#watcher.on('add', (filePath) => {
+      this.#handleHmrWatcherEvent({ filePath, action: 'add', displayLabel: 'add' })
+    })
+    this.#watcher.on('change', (filePath) => {
+      this.#handleHmrWatcherEvent({ filePath, action: 'change', displayLabel: 'update' })
+    })
+    this.#watcher.on('unlink', (filePath) => {
+      this.#handleHmrWatcherEvent({ filePath, action: 'unlink', displayLabel: 'delete' })
+    })
   }
 
   /**
@@ -822,47 +889,7 @@ export class DevServer {
     this.ui.logger.info('starting HTTP server...')
     await this.#startHTTPServer(this.#stickyPort)
 
-    /**
-     * Create watcher
-     */
-    this.#watcher = watch({
-      usePolling: options?.poll ?? false,
-      cwd: this.cwdPath,
-      ignoreInitial: true,
-      ignored: (file, stats) => {
-        if (!stats) {
-          return false
-        }
-
-        if (file.includes('inertia') && !file.includes('node_modules')) {
-          return false
-        }
-
-        if (stats.isFile()) {
-          return !this.#fileSystem.shouldWatchFile(file)
-        }
-        return !this.#fileSystem.shouldWatchDirectory(file)
-      },
-    })
-
-    /**
-     * Notify the watcher is ready
-     */
-    this.#watcher.on('ready', () => {
-      this.ui.logger.info('watching file system for changes...')
-    })
-
-    /**
-     * Cleanup when watcher dies
-     */
-    this.#watcher.on('error', (error: any) => {
-      this.ui.logger.warning('file system watcher failure')
-      this.ui.logger.fatal(error as any)
-
-      this.#onError?.(error)
-      this.#watcher?.close()
-    })
-
+    this.#watcher = this.#createWatcher({ poll: options?.poll })
     this.#watcher.on('add', (filePath) => {
       const relativePath = string.toUnixSlash(filePath)
       const absolutePath = join(this.cwdPath, relativePath)

tests/dev_server.spec.ts

@@ -539,6 +539,73 @@ test.group('DevServer', () => {
     assert.lengthOf(indexGenerationLogs, 3)
   }).timeout(10 * 1000)
 
+  test('restart server on file change when child process has crashed in hmr mode', async ({
+    fs,
+    assert,
+    cleanup,
+  }) => {
+    /**
+     * Create a server that crashes immediately after sending ready message
+     */
+    await fs.createJson('tsconfig.json', { include: ['**/*'], exclude: [] })
+    await fs.create(
+      'bin/server.ts',
+      `
+        process.send({ isAdonisJS: true, environment: 'web', port: process.env.PORT, host: 'localhost' })
+        setTimeout(() => { throw new Error('crash') }, 100)
+      `
+    )
+    await fs.create('app/controllers/home_controller.ts', 'export default class {}')
+    await fs.create('.env', 'PORT=3350')
+
+    const devServer = new DevServer(fs.baseUrl, {
+      hmr: true,
+      nodeArgs: [],
+      scriptArgs: [],
+      clearScreen: false,
+    })
+
+    devServer.ui = cliui()
+    devServer.ui.switchMode('raw')
+
+    await devServer.start()
+    cleanup(() => devServer.close())
+
+    /**
+     * Wait for the server to crash
+     */
+    await sleep(500)
+
+    /**
+     * Modify a file, should trigger a restart since the child is dead
+     */
+    await fs.create('app/controllers/home_controller.ts', 'export default class { foo() {} }')
+
+    await sleep(1000)
+
+    const logMessages = devServer.ui.logger.getLogs().map(({ message }) => message)
+    console.log(logMessages)
+
+    assert.snapshot(logMessages).matchInline(`
+      [
+        "[ blue(info) ] starting server in hmr mode...",
+        "[ blue(info) ] loading hooks...",
+        "[ blue(info) ] generating indexes...",
+        "[ blue(info) ] starting HTTP server...",
+        "Server address: cyan(http://localhost:3350)
+      Mode: cyan(hmr)
+      Press dim(h) to show help",
+        "[ blue(info) ] watching file system for changes...",
+        "[ blue(info) ] Underlying HTTP server died. Still watching for changes",
+        "green(update) app/controllers/home_controller.ts",
+        "Server address: cyan(http://localhost:3350)
+      Mode: cyan(hmr)
+      Press dim(h) to show help",
+        "[ blue(info) ] Underlying HTTP server died. Still watching for changes",
+      ]
+    `)
+  }).timeout(10 * 1000)
+
   test('define hooks as inline functions', async ({ fs, assert, cleanup }) => {
     let hooksStack: string[] = []