feat: add getAvailablePort helper function

test/unit/helpers.test.ts

@@ -1,5 +1,5 @@
 import { promises as fs } from "fs"
-import { tmpdir, useEnv } from "../../test/utils/helpers"
+import { getAvailablePort, tmpdir, useEnv } from "../../test/utils/helpers"
 
 /**
  * This file is for testing test helpers (not core code).
@@ -39,3 +39,16 @@ describe("useEnv", () => {
     expect(process.env[envKey]).toEqual("test environment variable")
   })
 })
+
+describe("getAvailablePort", () => {
+  it("should return a valid port", async () => {
+    const port = await getAvailablePort()
+    expect(port).toBeGreaterThan(0)
+    expect(port).toBeLessThanOrEqual(65535)
+  })
+  it("should return different ports for different calls", async () => {
+    const portOne = await getAvailablePort()
+    const portTwo = await getAvailablePort()
+    expect(portOne).not.toEqual(portTwo)
+  })
+})

test/unit/node/proxy.test.ts

@@ -6,6 +6,7 @@ import { HttpCode } from "../../../src/common/http"
 import { proxy } from "../../../src/node/proxy"
 import * as httpserver from "../../utils/httpserver"
 import * as integration from "../../utils/integration"
+import { getAvailablePort } from "../../utils/helpers"
 
 describe("proxy", () => {
   const nhooyrDevServer = new httpserver.HttpServer()
@@ -166,14 +167,16 @@ describe("proxy", () => {
 // src/node/proxy.ts, you should probably add it to
 // this test suite.
 describe("proxy (standalone)", () => {
-  const PORT = 9003
-  const PROXY_PORT = 8003
-  const URL = `http://localhost:${PORT}`
-  const PROXY_URL = `http://localhost:${PROXY_PORT}`
+  let URL = ""
+  let PROXY_URL = ""
   let testServer: http.Server
   let proxyTarget: http.Server
 
   beforeEach(async () => {
+    const PORT = await getAvailablePort()
+    const PROXY_PORT = await getAvailablePort()
+    URL = `http://localhost:${PORT}`
+    PROXY_URL = `http://localhost:${PROXY_PORT}`
     // Define server and a proxy server
     testServer = http.createServer((req, res) => {
       proxy.web(req, res, {