Option to read response body even if context is canceled?

[abraithwaite]

Hey Folks!

Maybe this is already supported and I just can't figure out how to do it but we'd like to read the response body even in the case that the request context is canceled.

Use case is as such:

We're building a query API which will often be running long queries.
We want to provide for the ability to cancel queries that are currently running synchronously.
We can do that by adding a cancelation to the context of the request. This works already.
However, when we cancel the context we get a nil response and the context canceled error.

We'd like to be able to deserialize the response body even in the event of request cancelation, and not just receive the cancelation error. The response body will have the queryID that was canceled which is useful in reporting status back to the UI.

It appears that this is not possible digging into the core_do.go code, but maybe I just haven't figured out how to do this properly.

requests/core_do.go

Lines 16 to 20 in 02ba493

	func do(cl *http.Client, req *http.Request, validators []ResponseHandler, h ResponseHandler) (doResponse, error) {
	res, err := cl.Do(req)
	if err != nil {
	return doConnect, err
	}

1. Is it possible? Would someone help point me in the right direction (docs, examples) to support this?
2. If not, is there interest in supporting it?

[earthboundkid]

If the context is cancelled, the body will either be truncated or nil, no?

[abraithwaite]

Oh dear, the issue is below this library. 😅 Sorry about that! Could have sworn I'd done this before with the standard library but just wrote a test to verify I myself was hallucinating.

Nevermind me then! Thanks for the amazing library!

FWIW for those coming here later, it's possible on the server side to catch the request cancelation and write a different response. Apparently that's not the case on the client side. I'll search the go issues to see if there's any interest in this.

[acehinnnqru]

I think the Go std lib had added an api WithoutCancel in the context package which could shadow the previous effects of WithCancel of your Context.