fix: fix bug when re-listening the server

src/index.ts

@@ -1,7 +1,7 @@
 import assert from 'node:assert'
 import { once } from 'node:events'
 import http from 'node:http'
-import { type AddressInfo } from 'node:net'
+import { type AddressInfo, type Socket } from 'node:net'
 
 import { createServerAdapter } from '@whatwg-node/server'
 import pDefer from 'p-defer'
@@ -56,7 +56,7 @@ export function createServer(options: ServerOptions) {
 		options.keyPair = Agent.keyPair()
 	}
 
-	const deferredListen = pDefer<ListenResult>()
+	let deferredListen = pDefer<ListenResult>()
 	const context = new Context({
 		...options,
 		keyPair: options.keyPair,
@@ -86,8 +86,8 @@ export function createServer(options: ServerOptions) {
 	})
 
 	// Track connections for proper cleanup
-	const connections = new Set<any>()
-	const onConnection = (socket: any) => {
+	const connections = new Set<Socket>()
+	const onConnection = (socket: Socket) => {
 		connections.add(socket)
 		socket.once('close', () => {
 			connections.delete(socket)
@@ -124,6 +124,8 @@ export function createServer(options: ServerOptions) {
 				once(localHttpServer, 'close'),
 				once(secretStreamServer, 'close'),
 			])
+			// Reset deferred listen for potential restart with different ports
+			deferredListen = pDefer<ListenResult>()
 		},
 	}
 }

test/server-restart.test.ts

@@ -0,0 +1,141 @@
+import fs from 'node:fs/promises'
+import os from 'node:os'
+import path from 'node:path'
+
+import { Agent as SecretStreamAgent } from 'secret-stream-http'
+import { describe, it, expect } from 'vitest'
+
+import { createServer } from '../src/index.js'
+import { DEMOTILES_Z2, OSM_BRIGHT_Z6 } from './helpers.js'
+
+describe('Server Restart', () => {
+	it('should use new ports when restarted with different ports', async (t) => {
+		const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'map-server-test-'))
+		const tmpCustomMapPath = path.join(tmpDir, 'custom-map.smp')
+		await fs.copyFile(OSM_BRIGHT_Z6, tmpCustomMapPath)
+
+		t.onTestFinished(async () => {
+			await fs.rm(tmpDir, { recursive: true, force: true }).catch(() => {})
+		})
+
+		const keyPair = SecretStreamAgent.keyPair()
+		const receiverKeyPair = SecretStreamAgent.keyPair(Buffer.alloc(32, 1))
+		const receiverDeviceId = Buffer.from(receiverKeyPair.publicKey).toString(
+			'hex',
+		)
+
+		const server = createServer({
+			defaultOnlineStyleUrl: 'https://demotiles.maplibre.org/style.json',
+			customMapPath: tmpCustomMapPath,
+			fallbackMapPath: DEMOTILES_Z2,
+			keyPair,
+		})
+
+		// First listen - use specific ports
+		const firstResult = await server.listen({
+			localPort: 0,
+			remotePort: 0,
+		})
+		const firstLocalPort = firstResult.localPort
+		const firstRemotePort = firstResult.remotePort
+
+		// Create a map share to capture the remote port being used
+		const firstShareResponse = await fetch(
+			`http://127.0.0.1:${firstLocalPort}/mapShares`,
+			{
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({
+					mapId: 'custom',
+					receiverDeviceId,
+				}),
+			},
+		)
+		expect(firstShareResponse.status).toBe(201)
+		const firstShare = await firstShareResponse.json()
+
+		// The mapShareUrls should contain the first remote port
+		expect(firstShare.mapShareUrls).toBeDefined()
+		expect(firstShare.mapShareUrls.length).toBeGreaterThan(0)
+		const firstUrl = new URL(firstShare.mapShareUrls[0])
+		expect(firstUrl.port).toBe(String(firstRemotePort))
+
+		// Close the server
+		await server.close()
+
+		// Listen again - ports will be different (since we use 0)
+		const secondResult = await server.listen({
+			localPort: 0,
+			remotePort: 0,
+		})
+		const secondLocalPort = secondResult.localPort
+		const secondRemotePort = secondResult.remotePort
+
+		// Ports should be different (very likely with port 0)
+		// At minimum, the listen result should reflect the new ports
+		expect(secondResult.localPort).not.toBe(firstLocalPort)
+
+		// Create another map share - this should use the NEW remote port
+		const secondShareResponse = await fetch(
+			`http://127.0.0.1:${secondLocalPort}/mapShares`,
+			{
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({
+					mapId: 'custom',
+					receiverDeviceId,
+				}),
+			},
+		)
+		expect(secondShareResponse.status).toBe(201)
+		const secondShare = await secondShareResponse.json()
+
+		// The mapShareUrls should contain the SECOND remote port, not the first
+		expect(secondShare.mapShareUrls).toBeDefined()
+		expect(secondShare.mapShareUrls.length).toBeGreaterThan(0)
+		const secondUrl = new URL(secondShare.mapShareUrls[0])
+
+		// This is the key assertion - the URL should have the new port
+		expect(secondUrl.port).toBe(String(secondRemotePort))
+		expect(secondUrl.port).not.toBe(String(firstRemotePort))
+
+		// Clean up
+		await server.close()
+	})
+
+	it('should work correctly after multiple restart cycles', async (t) => {
+		const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'map-server-test-'))
+		const tmpCustomMapPath = path.join(tmpDir, 'custom-map.smp')
+		await fs.copyFile(OSM_BRIGHT_Z6, tmpCustomMapPath)
+
+		t.onTestFinished(async () => {
+			await fs.rm(tmpDir, { recursive: true, force: true }).catch(() => {})
+		})
+
+		const server = createServer({
+			defaultOnlineStyleUrl: 'https://demotiles.maplibre.org/style.json',
+			customMapPath: tmpCustomMapPath,
+			fallbackMapPath: DEMOTILES_Z2,
+		})
+
+		const ports: number[] = []
+
+		// Restart 3 times
+		for (let i = 0; i < 3; i++) {
+			const result = await server.listen({ localPort: 0, remotePort: 0 })
+			ports.push(result.localPort)
+
+			// Verify server is working
+			const response = await fetch(
+				`http://127.0.0.1:${result.localPort}/maps/custom/style.json`,
+			)
+			expect(response.status).toBe(200)
+
+			await server.close()
+		}
+
+		// All ports should be different (extremely likely with port 0)
+		const uniquePorts = new Set(ports)
+		expect(uniquePorts.size).toBe(3)
+	}, 20_000) // On node 18 restarting can be slow.
+})