MockAgent delayed response with AbortSignal

[atlowChemi]

Bug Description

MockAgent with delayed responses handle the reply even for aborted controllers, possibly causing an uncaughtException error when an AbortSignal aborted the request.

I noticed this when trying to add the decompress interceptor, which has an assertion of assert(!this.#onErrorCalled) in onResponseStart, which in this case is being called after the controller was aborted.

Reproducible By

const { MockAgent, interceptors: { decompress } } = require('undici');
const agent = new MockAgent().compose(decompress());

const mockPool = agent.get('https://postman-echo.com');
mockPool.intercept({ path: '/delay/30', method: 'GET' }).reply(200, { success: true }, { headers: { 'content-type': 'application/json' } }).delay(30).times(2);

// This works:
const noSignal = await agent.request({ origin: 'https://postman-echo.com', path: '/delay/30', method: 'GET' });

// This raises an uncaughtException
const withSignal = await agent.request({ origin: 'https://postman-echo.com', path: '/delay/30', method: 'GET', signal: AbortSignal.timeout(10) });

Expected Behavior

Perhaps the pool's intercept should also receive a signal, to allow aborting such requests, or maybe mockDispatch's handleReply should handle aborted requests

[mcollina]

Thanks for reporting! Would you like to send a Pull Request to address this issue? Remember to add unit tests.

[atlowChemi]

Hi @mcollina, at the moment I am swamped and can't make the time for this at the moment.
I can get back to this in a couple of weeks if still relevant

[AryanBagade]

If @atlowChemi doesn’t mind, I’d love to create a PR for it. Please let me know!