fix: fix bug when re-listening the server (#16)

* fix: small type fix

* test: add failing test for server restart with changed ports

The deferredListen promise is not reset when close() is called, causing
getRemotePort() to return stale port values after server restart.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: reset deferredListen promise on server close

Ensures that when the server is restarted with listen() after close(),
the getRemotePort function returns the new port values instead of the
stale values from the previous listen() call.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: increase test timeout on node 18

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: gmaclennan

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.
+})