Re: [PATCH/RFC/GSOC] make git-pull a builtin

[Paul Tan <pyokagan@gmail.com>]

Hi,

Thanks for the review, though I would like to work on the proposal now
before the deadline passes :)

On Thu, Mar 19, 2015 at 1:52 AM, Matthieu Moy
<Matthieu.Moy@grenoble-inp.fr> wrote:
> Paul Tan <pyokagan@gmail.com> writes:
>
>> Ideally, I think the solution is to
>> improve the test suite and make it as comprehensive as possible, but
>> writing a comprehensive test suite may be too time consuming.
>
> time-consuming, but also very beneficial since the code would end up
> being better tested. For sure, a rewrite is a good way to break stuff,
> but anything untested can also be broken by mistake rather easily at any
> time.
>
> I'd suggest doing a bit of manual mutation testing: take your C code,
> comment-out a few lines of code, see if the tests still pass, and if
> they do, add a failing test that passes again once you uncomment the
> code.

Maybe code coverage tools could help here so we only need to focus on
the code paths that are untested by the test suite. At the minimum,
all of the non-trivial code paths in both the shell script and the
converted builtin must be covered by tests. This should help to
eliminate most sources of breakages. Anything further than that would
require an experienced understanding of all the possible important
inputs to be tested, which I personally feel would make the project
quite tedious.

I see git already has gcov support. For shell scripts, maybe kcov[1]
could be used. With some slight code changes, I managed to generate a
report for the git-pull tests[2] which should at least provide a good
starting point for how the tests can be improved.

[1] http://simonkagstrom.github.io/kcov/
[2] <http://www.googledrive.com/host/0B4O2AiYulllpfmJlTW4xT050OVVicnNWWS02dm52aTJ2TFIwQ2QwdWh0VHotSkU4eUNNWjg>

Regards,
Paul