testing: Avoid using context.Background

[gauravgahlot]

Fixes: #1878

[gauravgahlot]

I have intentionally split the changes into commits based on the parent directory. This will make it easier for me to do any changes suggested during the review.

@dfawley Could you please add no release notes label and also take a look at the changes?

[easwars]

We don't want to change context.Background() with context.TODO(). What we want instead is what @dfawley mentioned in #1878 (comment).

Each test file (one per package) should define a defaultTestTimeout. And each test must create a local context with the appropriate timeout.

const defaultTestTimeout = 10 * time.Second

func TestXxx(t *testing.T) {
  ctx, cancel := context.WithTimeout(defaultTestTimeout)
  defer cancel()

  // Do stuff and pass `ctx` to functions which accept one.
}

And for places where we block on some event not happening, we should define a much shorter timeout (something of the order of 10ms), create a new context with that short deadline, and use that.

Hope this helps.

Thanks.

[gauravgahlot]

Thanks for the explanation @easwars. I clearly misinterpreted @dfawley's comment.

I have made changes to the last commit. Please take a look and let me know if I'm doing it right this time.
If so, I will update the rest of the commits.

Thanks again. :)

[easwars]

I checked the last commit. The changes look mostly OK. I left some minor comments. Thank you so very much for doing this.

[easwars]

Thank you so very much.

[easwars]

Can't we use the ctx created in line 1272 here? And do a defer cancel()

[gauravgahlot]

That's right. I will do a fix and rebase. Thanks. :)

[gauravgahlot]

Thank you so very much.

I'm super glad I could contribute. Please let me what I can pick next. 🚀

[easwars]

@gauravgahlot : Could you please take care of the test failure here: https://github.com/grpc/grpc-go/pull/3949/checks?check_run_id=1340435962. Thanks.

[gauravgahlot]

@easwars I have fixed the issue and it should be good to go now. 🚀