Tear down what a test opens in t.after so a failing assertion ends the run

test/teardown.ts

@@ -0,0 +1,21 @@
+import type { CloseOptions } from '../src/session-options.ts';
+import type { Server, Socket } from 'node:net';
+import type { TestContext } from 'node:test';
+
+type Closable = { close: (options: CloseOptions) => Promise<unknown> };
+
+/** Aborted: a cleanup that drained would hang the run in exactly the case it exists for. */
+export function closeAfter(t: TestContext, closable: Closable): void {
+	t.after(() => closable.close({ signal: AbortSignal.abort() }));
+}
+
+/** A listener with a socket still on it never closes, so the sockets go first. */
+export function endListenerAfter(t: TestContext, listener: Server, sockets: Socket[]): void {
+	t.after(async () => {
+		for (const sock of sockets) {
+			sock.destroy();
+		}
+
+		await new Promise<void>(resolve => { listener.close(() => { resolve(); }); });
+	});
+}