net/http/httptest: add NewRequestWithContext

[kevinburke]

Recently the net/http package added NewRequestWithContext, which allows callers to pass in a context.Context without a second method call and/or copying the http.Request.

The proposal is to add the same API to httptest, so users don't need to think about it or wonder why httptest does not expose the same API as net/http for creating requests.

Updates #23544.

[ianlancetaylor]

CC @neild @bradfitz

[neild]

Seems reasonable to me.

[kevinburke]

Does this need to go to the proposal committee or should I just submit a CL?

[gopherbot]

Change https://go.dev/cl/548355 mentions this issue: net/http/httptest: add NewRequestWithContext

[neild]

This does need to be approved by the proposal committee, since it's adding a new exported function.

I think this change is reasonable, and support it.

[rsc]

Based on the discussion above, this proposal seems like a likely accept.
— rsc for the proposal review group

The proposal is to add

func NewRequestWithContext(ctx context.Context, method, target string, body io.Reader) *http.Request

that behaves like httptest.NewRequest except it also adds a context.

[rsc]

No change in consensus, so accepted. 🎉
This issue now tracks the work of implementing the proposal.
— rsc for the proposal review group

The proposal is to add

func NewRequestWithContext(ctx context.Context, method, target string, body io.Reader) *http.Request

that behaves like httptest.NewRequest except it also adds a context.

[odeke-em]

This got implemented by @kevinburke in CL https://go-review.googlesource.com/c/go/+/548355 but it used "Updates #NNN" instead of "Fixes #NNN" so Github didn't auto-close the issue, hence I am closing it right now. Thank you Kevin!