Re: credential helper tests

> Since we've had a few credential helpers posted to the list recently, I
> really want to try them all out. This can be a little bit tricky for
> automated testing, though, for two reasons:
>
>   - they run on lots of platforms with lots of dependencies
>
>   - they interact with parts of the systems that are opaque to git. So
>     we can't make a test that reliably simulates "and then the user
>     types 'foo' into a dialog box" across all platforms.
>
> Instead, I came up with a separate test script that is intended to be
> run interactively with the user. It runs the helpers through a battery
> of tests, and tells the user what to expect and what to input to any
> dialogs or prompts.
>
> I've run it already on the helpers I've written. I plan on running it
> with the helpers that have been posted, as well. But I also wanted to
> make it public so that authors could use it as a development aid.
>
> It's not integrated with git's tests at all. In theory it could be part
> of t/, but disabled unless the user asks for it. However, I'm not sure
> that makes much sense. It's intended to test helpers that aren't
> necessarily even shipped with git, and wouldn't necessarily even need
> git to run.