Re: [PATCH v2 1/2] test-lib: add a function to compare an expection with stdout from a command

> On Sat, Apr 16, 2016 at 11:07:02PM -0400, Eric Sunshine wrote:
>> > test_stdout accepts an expection and a command to execute.  It will execute
>> > the command and then compare the stdout from that command to an expectation.
>> > If the expectation is not met, a mock diff output is written to stderr.
>>
>> I wonder if this deserves more flexibility by accepting a comparison
>> operator, such as = and !=, similar to test_line_count()? Although, I
>> suppose such functionality could be added later if deemed useful.
>
> [...] Though I do actually find that:
>
>   test_stdout false git rev-parse --whatever
>
> isn't great, because there's no syntactic separator between the expected
> output and the actual command to run. So I dunno, maybe it would be
> better as:
>
>   test_stdout false = git rev-parse --whatever
>
> [...] We could also do:
>
>   test_stdout git rev-parse --whatever <<-\EOF
>   false
>   EOF
>
> which is more robust for multi-line output, but I think part of the
> point is to keep these as simple one-liners. You're not buying all that
> much over:
>
>   cat >expect <<-\EOF &&
>   false
>   EOF
>   git rev-parse --whatever >actual &&
>   test_cmp expect actual
>
> Though I do admit I've considered such a helper for some tests where
> that pattern is repeated ad nauseam.