fix(dev): hotfix by force closing nitro sockets

packages/nuxt-cli/package.json

@@ -12,6 +12,7 @@
   "exports": {
     ".": "./dist/index.mjs",
     "./cli": "./bin/nuxi.mjs",
+    "./runtime/dev-close-sockets": "./runtime/dev-close-sockets.mjs",
     "./runtime/dev-request-context": "./runtime/dev-request-context.mjs"
   },
   "types": "./dist/index.d.ts",

packages/nuxt-cli/runtime/dev-close-sockets.mjs

@@ -0,0 +1,22 @@
+import { subscribe, unsubscribe } from 'node:diagnostics_channel'
+
+/**
+ * Destroy sockets left open in the Nitro dev worker on shutdown, including
+ * upgraded ones that `server.closeAllConnections()` skips.
+ *
+ * TODO: remove once https://github.com/nitrojs/nitro/pull/4671 is released.
+ */
+export default function (nitroApp) {
+  const sockets = new Set()
+  const track = ({ socket }) => {
+    sockets.add(socket)
+    socket.once('close', () => sockets.delete(socket))
+  }
+  subscribe('net.server.socket', track)
+  nitroApp.hooks.hook('close', () => {
+    unsubscribe('net.server.socket', track)
+    for (const socket of sockets) {
+      socket.destroy()
+    }
+  })
+}

packages/nuxt-cli/src/dev/utils.ts

@@ -72,6 +72,16 @@ function registerRequestContextPlugin(nitro: NitroConfigForHook, cwd: string): v
   }
 }
 
+function registerCloseSocketsPlugin(nitro: NitroConfigForHook): void {
+  try {
+    nitro.plugins ||= []
+    nitro.plugins.push(fileURLToPath(import.meta.resolve('@nuxt/cli/runtime/dev-close-sockets')))
+  }
+  catch (error) {
+    debug('Could not resolve the close sockets plugin:', error)
+  }
+}
+
 /**
  * The `consola` the app itself logs through, which is the one
  * `@nuxt/nitro-server` wraps `console` with: its own, not the CLI's. Reporting
@@ -889,17 +899,16 @@ export class NuxtDevServer extends EventEmitter<DevServerEventMap> {
           clearScreen: this.options.clear,
           ...this.options.overrides.vite,
         },
-        ...captureUIEvents
-          ? {
-              hooks: {
-                ...this.options.overrides.hooks,
-                'nitro:config': (nitro) => {
-                  registerRequestContextPlugin(nitro, this.options.cwd)
-                  return this.options.overrides.hooks?.['nitro:config']?.(nitro)
-                },
-              } satisfies NuxtConfig['hooks'],
+        hooks: {
+          ...this.options.overrides.hooks,
+          'nitro:config': (nitro) => {
+            registerCloseSocketsPlugin(nitro)
+            if (captureUIEvents) {
+              registerRequestContextPlugin(nitro, this.options.cwd)
             }
-          : {},
+            return this.options.overrides.hooks?.['nitro:config']?.(nitro)
+          },
+        } satisfies NuxtConfig['hooks'],
       },
     }
 

packages/nuxt-cli/test/e2e/dev-websocket-shutdown.spec.ts

@@ -0,0 +1,55 @@
+import { spawn } from 'node:child_process'
+import { once } from 'node:events'
+import { mkdir, writeFile } from 'node:fs/promises'
+import { join } from 'node:path'
+import process from 'node:process'
+import { fileURLToPath } from 'node:url'
+import { getPort } from 'get-port-please'
+import { describe, expect, it } from 'vitest'
+import { createDevFixture } from '../utils'
+
+const nuxi = fileURLToPath(new URL('../../bin/nuxi.mjs', import.meta.url))
+const fixtureDir = await createDevFixture('dev-websocket-shutdown')
+await writeFile(join(fixtureDir, 'nuxt.config.ts'), 'export default defineNuxtConfig({ nitro: { experimental: { websocket: true } } })\n')
+await mkdir(join(fixtureDir, 'server/routes'), { recursive: true })
+await writeFile(join(fixtureDir, 'server/routes/_ws.ts'), 'export default defineWebSocketHandler({ message(peer, message) { peer.send(message.text()) } })\n')
+
+describe('dev server shutdown', () => {
+  it('should exit promptly with an open websocket connection', { timeout: 120_000 }, async () => {
+    const host = '127.0.0.1'
+    const port = await getPort({ host, port: 3060 })
+    // nitropack skips its graceful worker shutdown under test and CI
+    const env = Object.fromEntries(Object.entries(process.env).filter(([key]) => !['CI', 'TEST', 'VITEST', 'NODE_ENV', 'GITHUB_ACTIONS'].includes(key)))
+    const child = spawn(process.execPath, [nuxi, 'dev', '--no-fork', '--host', host, '--port', String(port)], {
+      cwd: fixtureDir,
+      env: { ...env, NO_COLOR: '1' },
+      stdio: ['ignore', 'pipe', 'pipe'],
+    })
+    let output = ''
+    const append = (data: string) => {
+      output += data
+    }
+    child.stdout.on('data', append)
+    child.stderr.on('data', append)
+
+    try {
+      await expect.poll(() => output, { timeout: 90_000, interval: 250 }).toContain('Ready in')
+
+      const ws = new WebSocket(`ws://${host}:${port}/_ws`)
+      const echo = await new Promise<string>((resolve, reject) => {
+        ws.addEventListener('open', () => ws.send('ping'))
+        ws.addEventListener('message', event => resolve(String(event.data)))
+        ws.addEventListener('error', reject)
+      })
+      expect(echo).toBe('ping')
+
+      const start = performance.now()
+      child.kill('SIGINT')
+      await once(child, 'exit')
+      expect(performance.now() - start).toBeLessThan(5000)
+    }
+    finally {
+      child.kill('SIGKILL')
+    }
+  })
+})