fetch support delay

[mikicho]

• I had to patch the AbortSignal.timeout to get the delay for throwing the 'timeout' error without actually waiting for it.
• I'm wondering if it's worth it... signal is very general, and my current solution is for a very specific use case (AbortSignal.timeout function only), I'm not certain if it belongs in Nock.
• Currently, I reject the promise on the timeout event, which means the signal isn't really aborted. Is there an easy way to update the kAborted to true and kReason? We may override the signal with an aborted signal, but I'm afraid it would be fragile:

clientRequest.on('timeout', () => {
  init.signal = AbortSignal.abort(new DOMException('The operation was aborted due to timeout', 'TimeoutError'))
  reject(init.signal.reason)
})

@gr2m @Uzlopak WDYT?

[gr2m]

I tried to wrap my head around it but I don't have the mental capacity to think this through right now 🤕 I'd be okay with removing functionality from nock if that removes a blocker to ship beta, and then open a discussion on how to bring it back. The folks depending on it will then show up and share their use cases, and might even collaborate on a solution.

[Uzlopak]

I dont understand why it needs Abortcontroller? Does the normal delay also use a Abortcontroller? I would have expected a await new Promise(resolve => setTimeout(resolve, delay))

[mikicho]

After some thought, I think the delay connection doesn't make much sense with Fetch API, which doesn't provide this level of granularity.

Users should use time fakers instead if they don't want to wait.

Another option we may consider... Nahh probably a bad idea

Another option we may consider is to expose a new global property that enables users to define their time faker, which later we can use in the interception logic:

// setup
nock.setFakeTimer(sinon.useFakeTimers())

it(..., () => {
   nock(..).get(...).delay(2000).reply()
})

In Nock's interception logic, we can do the following:

nock.getFakeTimer().tick(interceptor.delay + 100);

WDYT?

[gr2m]

I would prefer not to make fake timers an API we support with nock. They are a recipe for headaches. I would rather remove the nock API for delays altogether.