coder · jakehwll · Jun 22, 2026 · Jun 22, 2026
diff --git a/site/e2e/helpers.ts b/site/e2e/helpers.ts
@@ -1,5 +1,6 @@
 import { type ChildProcess, exec, spawn } from "node:child_process";
 import { randomUUID } from "node:crypto";
+import type { Server } from "node:http";
 import net from "node:net";
 import path from "node:path";
 import { Duplex } from "node:stream";
@@ -865,17 +866,39 @@ export class Awaiter {
 	}
 }
 
-export const createServer = async (
-	port: number,
-): Promise<ReturnType<typeof express>> => {
+type MockServer = {
+	app: ReturnType<typeof express>;
+	/**
+	 * close stops the server and force-closes any lingering keep-alive
+	 * connections so the port is released promptly. Callers must invoke
+	 * this in their teardown (e.g. test.afterAll, try/finally) to avoid
+	 * leaking the listener into the next test run, which historically
+	 * caused EADDRINUSE flakes in this suite.
+	 */
+	close: () => Promise<void>;
+};
+
+export const createServer = async (port: number): Promise<MockServer> => {
 	await waitForPort(port); // Wait until the port is available
 
-	const e = express();
+	const app = express();
 	// We need to specify the local IP address as the web server
 	// tends to fail with IPv6 related error:
 	// listen EADDRINUSE: address already in use :::50516
-	await new Promise<void>((r) => e.listen(port, "0.0.0.0", r));
-	return e;
+	const server = await new Promise<Server>((resolve) => {
+		const s = app.listen(port, "0.0.0.0", () => resolve(s));
+	});
+
+	return {
+		app,
+		close: () =>
+			new Promise<void>((resolve, reject) => {
+				// closeAllConnections (Node >= 18.2 / 16.17) forces lingering
+				// keep-alives to terminate so server.close() is bounded.
+				server.closeAllConnections?.();
+				server.close((err) => (err ? reject(err) : resolve()));
+			}),
+	};
 };
 
 async function waitForPort(

diff --git a/site/e2e/tests/externalAuth.spec.ts b/site/e2e/tests/externalAuth.spec.ts
@@ -14,8 +14,11 @@ import { beforeCoderTest, resetExternalAuthKey } from "../hooks";
 
 test.describe
 	.skip("externalAuth", () => {
+		let closeWebServer: (() => Promise<void>) | undefined;
+
 		test.beforeAll(async ({ baseURL }) => {
-			const srv = await createServer(gitAuth.webPort);
+			const { app: srv, close } = await createServer(gitAuth.webPort);
+			closeWebServer = close;
 
 			// The GitHub validate endpoint returns the currently authenticated user!
 			srv.use(gitAuth.validatePath, (_req, res) => {
@@ -34,6 +37,10 @@ test.describe
 			});
 		});
 
+		test.afterAll(async () => {
+			await closeWebServer?.();
+		});
+
 		test.beforeEach(async ({ context, page }) => {
 			beforeCoderTest(page);
 			await login(page);
@@ -51,43 +58,49 @@ test.describe
 			};
 
 			// Start a server to mock the GitHub API.
-			const srv = await createServer(gitAuth.devicePort);
-			srv.use(gitAuth.validatePath, (_req, res) => {
-				res.write(JSON.stringify(ghUser));
-				res.end();
-			});
-			srv.use(gitAuth.codePath, (_req, res) => {
-				res.write(JSON.stringify(device));
-				res.end();
-			});
-			srv.use(gitAuth.installationsPath, (_req, res) => {
-				res.write(JSON.stringify(ghInstall));
-				res.end();
-			});
+			const { app: srv, close: closeServer } = await createServer(
+				gitAuth.devicePort,
+			);
+			try {
+				srv.use(gitAuth.validatePath, (_req, res) => {
+					res.write(JSON.stringify(ghUser));
+					res.end();
+				});
+				srv.use(gitAuth.codePath, (_req, res) => {
+					res.write(JSON.stringify(device));
+					res.end();
+				});
+				srv.use(gitAuth.installationsPath, (_req, res) => {
+					res.write(JSON.stringify(ghInstall));
+					res.end();
+				});
 
-			const token = {
-				access_token: "",
-				error: "authorization_pending",
-				error_description: "",
-			};
-			// First we send a result from the API that the token hasn't been
-			// authorized yet to ensure the UI reacts properly.
-			const sentPending = new Awaiter();
-			srv.use(gitAuth.tokenPath, (_req, res) => {
-				res.write(JSON.stringify(token));
-				res.end();
-				sentPending.done();
-			});
+				const token = {
+					access_token: "",
+					error: "authorization_pending",
+					error_description: "",
+				};
+				// First we send a result from the API that the token hasn't been
+				// authorized yet to ensure the UI reacts properly.
+				const sentPending = new Awaiter();
+				srv.use(gitAuth.tokenPath, (_req, res) => {
+					res.write(JSON.stringify(token));
+					res.end();
+					sentPending.done();
+				});
 
-			await page.goto(`/external-auth/${gitAuth.deviceProvider}`, {
-				waitUntil: "domcontentloaded",
-			});
-			await page.getByText(device.user_code).isVisible();
-			await sentPending.wait();
-			// Update the token to be valid and ensure the UI updates!
-			token.error = "";
-			token.access_token = "hello-world";
-			await page.waitForSelector("text=1 organization authorized");
+				await page.goto(`/external-auth/${gitAuth.deviceProvider}`, {
+					waitUntil: "domcontentloaded",
+				});
+				await page.getByText(device.user_code).isVisible();
+				await sentPending.wait();
+				// Update the token to be valid and ensure the UI updates!
+				token.error = "";
+				token.access_token = "hello-world";
+				await page.waitForSelector("text=1 organization authorized");
+			} finally {
+				await closeServer();
+			}
 		});
 
 		test("external auth web", async ({ page }) => {