Fix mock server in ai runtime tests

Co-authored-by: Kent C. Dodds <me+github@kentcdodds.com>

Author: cursoragent

worker/ai-runtime.test.ts

@@ -1,4 +1,6 @@
 /// <reference types="bun" />
+import { createServer } from 'node:http'
+import { type AddressInfo } from 'node:net'
 import { expect, test, vi } from 'vitest'
 
 async function loadCreateAiRuntime(cacheKey = crypto.randomUUID()) {
@@ -8,25 +10,42 @@ async function loadCreateAiRuntime(cacheKey = crypto.randomUUID()) {
 }
 
 async function createMockServer() {
-	const server = Bun.serve({
-		port: 0,
-		fetch(request) {
-			const url = new URL(request.url)
-			if (url.pathname !== '/chat') {
-				return new Response('Not Found', { status: 404 })
-			}
-			return Response.json({
+	const server = createServer((request, response) => {
+		const url = new URL(request.url ?? '', 'http://127.0.0.1')
+		if (url.pathname !== '/chat') {
+			response.statusCode = 404
+			response.end('Not Found')
+			return
+		}
+
+		response.statusCode = 200
+		response.setHeader('Content-Type', 'application/json')
+		response.end(
+			JSON.stringify({
 				kind: 'text',
 				text: 'hello from mock runtime',
 				chunks: ['hello ', 'from ', 'mock runtime'],
-			})
-		},
+			}),
+		)
 	})
 
+	await new Promise<void>((resolve) => {
+		server.listen(0, '127.0.0.1', resolve)
+	})
+	const address = server.address() as AddressInfo
+
 	return {
-		baseUrl: `http://127.0.0.1:${server.port}`,
+		baseUrl: `http://127.0.0.1:${address.port}`,
 		[Symbol.asyncDispose]: async () => {
-			await server.stop()
+			await new Promise<void>((resolve, reject) => {
+				server.close((error) => {
+					if (error) {
+						reject(error)
+						return
+					}
+					resolve()
+				})
+			})
 		},
 	}
 }