bun.sh/test/js/bun/http/serve-direct-readable-stream.test.ts

import { sleep } from "bun";
import { expect, test } from "bun:test";

test("HTTPResponseSink displays correct message", async () => {
  let leakedCtrl: any;
  using server = Bun.serve({
    port: 0,
    async fetch(req) {
      return new Response(
        new ReadableStream({
          type: "direct",
          async pull(ctrl) {
            await ctrl.write("a");
            await sleep(10);
            await ctrl.write("b");
            ctrl.flush();
            leakedCtrl = ctrl;
          },
        } as any),
      );
    },
  });
  let response = await fetch(server.url);
  expect(await response.text()).toBe("ab");
  expect(() => leakedCtrl.write("c")).toThrow(
    'This HTTPResponseSink has already been closed. A "direct" ReadableStream terminates its underlying socket once `async pull()` returns.',
  );
  expect(() => leakedCtrl.write.call({}, "c")).toThrow("Expected HTTPResponseSink");
});