From f6f4714cf752bb3239da820b2710fde3af59f953 Mon Sep 17 00:00:00 2001
From: Daniel Roe <daniel@roe.dev>
Date: Tue, 6 Oct 2026 11:06:21 +0000
Subject: [PATCH] fix(dev): disable dev channels when `BroadcastChannel` is
 unavailable

---
 packages/nuxt-cli/src/dev/broadcast.ts        | 16 +++++++++++++
 packages/nuxt-cli/src/dev/error-channel.ts    | 14 ++++-------
 packages/nuxt-cli/src/dev/log-channel.ts      | 10 +++-----
 packages/nuxt-cli/src/dev/span-channel.ts     | 10 +++-----
 packages/nuxt-cli/test/unit/broadcast.spec.ts | 24 +++++++++++++++++++
 5 files changed, 51 insertions(+), 23 deletions(-)
 create mode 100644 packages/nuxt-cli/src/dev/broadcast.ts
 create mode 100644 packages/nuxt-cli/test/unit/broadcast.spec.ts

diff --git a/packages/nuxt-cli/src/dev/broadcast.ts b/packages/nuxt-cli/src/dev/broadcast.ts
new file mode 100644
index 000000000..3559b1b44
--- /dev/null
+++ b/packages/nuxt-cli/src/dev/broadcast.ts
@@ -0,0 +1,16 @@
+import { BroadcastChannel } from 'node:worker_threads'
+
+import { debug } from '../utils/logger'
+
+/** Listen on the channel called `name`, or return nothing where the runtime cannot open one. */
+export function openBroadcast<T>(name: string, onMessage: (data: T) => void): BroadcastChannel | undefined {
+  try {
+    const channel = new BroadcastChannel(name)
+    channel.unref()
+    channel.onmessage = (event: { data: T }) => onMessage(event.data)
+    return channel
+  }
+  catch (error) {
+    debug(`Could not open the \`${name}\` channel:`, error)
+  }
+}
diff --git a/packages/nuxt-cli/src/dev/error-channel.ts b/packages/nuxt-cli/src/dev/error-channel.ts
index f953bb817..d53fba8f6 100644
--- a/packages/nuxt-cli/src/dev/error-channel.ts
+++ b/packages/nuxt-cli/src/dev/error-channel.ts
@@ -6,11 +6,10 @@ import type { ProgressSnapshot } from '../utils/progress-snapshot'
 
 import process from 'node:process'
 
-import { BroadcastChannel } from 'node:worker_threads'
-
 import { isAbsolute, join, relative } from 'pathe'
 
 import { debug } from '../utils/logger'
+import { openBroadcast } from './broadcast'
 import { isLoopbackAddress } from './host-check'
 import { DEV_INTERNAL_PREFIX } from './progress'
 
@@ -332,11 +331,7 @@ export interface ErrorBridgeHandlers {
  * until the returned function is called.
  */
 export function openErrorBridge(handlers: ErrorBridgeHandlers = {}, options: ErrorChannelOptions = {}): () => void {
-  const broadcast = new BroadcastChannel(ERROR_BROADCAST_CHANNEL)
-  broadcast.unref()
-  broadcast.postMessage(SYNC_MESSAGE)
-  broadcast.onmessage = (event: { data: unknown }) => {
-    const message = event.data
+  const broadcast = openBroadcast(ERROR_BROADCAST_CHANNEL, (message: unknown) => {
     if (!isDevErrorMessage(message)) {
       return
     }
@@ -368,8 +363,9 @@ export function openErrorBridge(handlers: ErrorBridgeHandlers = {}, options: Err
         }
       }
     }).catch(error => debug('Could not handle a forwarded error report:', error))
-  }
-  return () => broadcast.close()
+  })
+  broadcast?.postMessage(SYNC_MESSAGE)
+  return () => broadcast?.close()
 }
 
 export async function closeErrorChannel(): Promise<void> {
diff --git a/packages/nuxt-cli/src/dev/log-channel.ts b/packages/nuxt-cli/src/dev/log-channel.ts
index 5f19553ac..e46bb6ab0 100644
--- a/packages/nuxt-cli/src/dev/log-channel.ts
+++ b/packages/nuxt-cli/src/dev/log-channel.ts
@@ -1,4 +1,4 @@
-import { BroadcastChannel } from 'node:worker_threads'
+import { openBroadcast } from './broadcast'
 
 export interface ServerLogEvent {
   level: number
@@ -26,10 +26,6 @@ export const DEV_LOG_CHANNEL = 'nuxt:dev:log'
 
 /** Receive the app's logs until the returned function is called. */
 export function openDevLogChannel(sink: (log: ServerLogEvent) => void): () => void {
-  const channel = new BroadcastChannel(DEV_LOG_CHANNEL)
-  channel.unref()
-  channel.onmessage = (event: { data: ServerLogEvent }) => {
-    sink(event.data)
-  }
-  return () => channel.close()
+  const channel = openBroadcast(DEV_LOG_CHANNEL, sink)
+  return () => channel?.close()
 }
diff --git a/packages/nuxt-cli/src/dev/span-channel.ts b/packages/nuxt-cli/src/dev/span-channel.ts
index 0f0ae7721..9faed9537 100644
--- a/packages/nuxt-cli/src/dev/span-channel.ts
+++ b/packages/nuxt-cli/src/dev/span-channel.ts
@@ -1,4 +1,4 @@
-import { BroadcastChannel } from 'node:worker_threads'
+import { openBroadcast } from './broadcast'
 
 /** A timed piece of work the app did while serving a request. */
 export interface DevRequestSpan {
@@ -29,10 +29,6 @@ const DEV_SPAN_CHANNEL = 'nuxt:dev:span'
 
 /** Receive the app's spans until the returned function is called. */
 export function openDevSpanChannel(sink: (span: DevRequestSpan) => void): () => void {
-  const channel = new BroadcastChannel(DEV_SPAN_CHANNEL)
-  channel.unref()
-  channel.onmessage = (event: { data: DevRequestSpan }) => {
-    sink(event.data)
-  }
-  return () => channel.close()
+  const channel = openBroadcast(DEV_SPAN_CHANNEL, sink)
+  return () => channel?.close()
 }
diff --git a/packages/nuxt-cli/test/unit/broadcast.spec.ts b/packages/nuxt-cli/test/unit/broadcast.spec.ts
new file mode 100644
index 000000000..4e9d2c088
--- /dev/null
+++ b/packages/nuxt-cli/test/unit/broadcast.spec.ts
@@ -0,0 +1,24 @@
+import { describe, expect, it, vi } from 'vitest'
+
+import { openErrorBridge } from '../../src/dev/error-channel'
+import { openDevLogChannel } from '../../src/dev/log-channel'
+import { openDevSpanChannel } from '../../src/dev/span-channel'
+
+vi.mock('node:worker_threads', async importOriginal => ({
+  ...await importOriginal<typeof import('node:worker_threads')>(),
+  BroadcastChannel: class {
+    constructor() {
+      throw new TypeError('Cannot read properties of undefined (reading \'on\')')
+    }
+  },
+}))
+
+describe('dev channels', () => {
+  it.each([
+    ['log', () => openDevLogChannel(() => {})],
+    ['span', () => openDevSpanChannel(() => {})],
+    ['error', () => openErrorBridge()],
+  ])('should open and close the %s channel when `BroadcastChannel` cannot be constructed', (_, open) => {
+    expect(() => open()()).not.toThrow()
+  })
+})