fix(dev): restore isolated environment host defaults

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

@@ -152,7 +152,8 @@ function createSecureServer(certificate: ResolvedCertificate, handler: RequestLi
 }
 
 export async function listen(handler: RequestListener, options: ListenOptions = {}): Promise<Listener> {
-  const hostname = validateHostname(options.hostname, options.public) ?? (options.public ? '' : 'localhost')
+  const isolatedEnvironment = options.hostname === undefined && !options.public && detectIsolatedEnvironment()
+  const hostname = validateHostname(options.hostname, options.public) ?? (options.public || isolatedEnvironment ? '' : 'localhost')
 
   const requestedPort = options.port === undefined || options.port === '' ? undefined : Number(options.port)
   const port = options.handover && requestedPort

packages/nuxt-cli/test/unit/listen.spec.ts

@@ -1,14 +1,20 @@
 import type { Listener } from '../../src/dev/listen'
 
+import { connect } from 'node:net'
 import { networkInterfaces } from 'node:os'
 
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
 import { copyURL, formatDisplayURL, getNetworkAddresses, isReusePortSupported, listen, openBrowser, resolveOpenCommand, validateHostname } from '../../src/dev/listen'
 
 const writeText = vi.hoisted(() => vi.fn())
+const isolatedEnvironment = vi.hoisted(() => ({ current: undefined as string | undefined }))
 
 vi.mock('tinyclip', () => ({ writeText }))
+vi.mock('../../src/dev/environment', () => ({
+  detectIsolatedEnvironment: () => isolatedEnvironment.current,
+  isWsl: (platform: NodeJS.Platform, env: NodeJS.ProcessEnv) => platform === 'linux' && !!env.WSL_DISTRO_NAME,
+}))
 
 const spawn = vi.hoisted(() => vi.fn((_command: string, _args: string[]) => ({
   once: () => {},
@@ -146,6 +152,7 @@ describe('listen', () => {
 
   afterEach(async () => {
     restoreEnvironment()
+    isolatedEnvironment.current = undefined
     await Promise.all(listeners.splice(0).map(listener => listener.close()))
   })
 
@@ -155,6 +162,24 @@ describe('listen', () => {
     return listener
   }
 
+  it('should accept connections on both loopback addresses in an isolated environment', async () => {
+    isolatedEnvironment.current = 'the container'
+    const listener = await start({ port: 0 })
+    const request = (host: string) => new Promise<string>((resolve, reject) => {
+      const socket = connect({ host, port: listener.address.port }, () => socket.write('GET / HTTP/1.0\r\n\r\n'))
+      let response = ''
+      socket.setEncoding('utf8')
+      socket.on('data', chunk => response += chunk)
+      socket.on('end', () => resolve(response))
+      socket.on('error', reject)
+    })
+
+    const responses = await Promise.all([request('127.0.0.1'), request('::1')])
+
+    expect(responses.every(response => response.endsWith('\r\n\r\nok'))).toBe(true)
+    expect(listener.url).toBe(`http://localhost:${listener.address.port}/`)
+  })
+
   it('should fall back to another port by default', async () => {
     const first = await start({ port: 0 })
     const second = await start({ port: first.address.port })

packages/nuxt-cli/test/unit/terminal-output.spec.ts

@@ -101,14 +101,12 @@ describe('dev server terminal output', () => {
       `)
     })
 
-    it('should say how to reach a loopback server from outside a container', async () => {
+    it('should expose the server inside a container', async () => {
       isolatedEnvironment.current = 'the container'
       const renderer = await render(() => start())
 
-      expect(screen(renderer)).toMatchInlineSnapshot(`
-        "  ➜ Local:    http://localhost:<port>/
-          ➜ Network:  use --host to reach this server from outside the container"
-      `)
+      expect(screen(renderer)).toContain('➜ Local:    http://localhost:<port>/')
+      expect(screen(renderer)).not.toContain('use --host')
     })
 
     it('should colour each url type differently', async () => {