Re: [PATCH 2/3] rebase: Add tests for console output

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 1, 2017, 23:40 UTC
Message-ID: <xmqq7f0v46q3.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <alpine.DEB.2.21.1.1706011329350.3610@virtualbox>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 9 quoted lines

> Also, about the commit IDs. As long as the tests are consistent (i.e. they
> use test_commit rather than plain `git commit`, or at least call
> `test_tick` beforehand), the commit IDs should actually be identical
> between runs and not depend on the time of day or the date.
>
> The only exception to that rule is when some previous test cases call
> `test_commit` but are guarded behind some prereq and may not be executed
> at all. In that case, the precise commit IDs depend on the particular set
> of active prereqs.

Good observation. The tests written such a way may make later introduction of new hash function troublesome, though (we already have tons of them, and it is already a hassle just imagining that we will have to migrate them X-<).

And what you gave below is an excellent suggestion to even solve that future headaches.

Show 27 quoted lines

> But as far as I can tell, t3420 does not have any test cases guarded by
> prereqs.
>
> Taking an additional step back, I wonder whether we have to hard-code the
> commit IDs (or XXX) to begin with. Why not generate the `expect` files
> with the information at hand? We can simply ask `git rev-parse --short`.
>
> For the stash's commit ID, there is no record in the ref space, of course
> (because it was created with `git stash create`). But I think in this
> case, it is legitimate to simply grep the output.
>
> That way, the test would be precise and resilient.
>
> So for example instead of adding the t/t3420/expected-success-am verbatim,
> you could generate the output via
>
> 	cat >expect <<-EOF
> 	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\\$" output)
> 	HEAD is now at $(git rev-parse --short HEAD~2) third commit
> 	First, rewinding head to replay your work on top of it...
> 	Applying: second commit
> 	Applying: third commit
> 	Applied autostash.
> 	EOF
>
> Ciao,
> Johannes