Function makeFetchHarness

apps/cloud/src/analytics/ema-rollout.test.ts:50–75

(
  respond: (request: CapturedRequest) => Response | Promise<Response>,
)

 * from it models a transport failure, and an aborted signal models the timeout.
 */
const makeFetchHarness = (
  respond: (request: CapturedRequest) => Response | Promise<Response>,
): FetchHarness => {
  const requests: CapturedRequest[] = [];
  const detached: Promise<unknown>[] = [];
  return {
    requests: () => requests,
    settle: async () => {
      await Promise.all(detached);
    },
    waitUntil: (work) => {
      detached.push(work);
    },
    fetch: async (input, init) => {
      const raw = typeof init?.body === "string" ? init.body : "{}";
      const captured: CapturedRequest = {
        url: String(input),
        // oxlint-disable-next-line executor/no-json-parse -- boundary: test fixture reads back the exact JSON body the gate serialized for PostHog
        body: JSON.parse(raw) as Record<string, unknown>,
        signal: init?.signal instanceof AbortSignal ? init.signal : null,
      };
      requests.push(captured);
      return respond(captured);
    },
  };
};

const jsonResponse = (body: unknown, status = 200): Response =>
  new Response(JSON.stringify(body), {