Fix gradient function and add test

[andreasnoack]

Fix #5320

[andreasnoack]

This one should also work for empty vectors except if they of type None. I think it is unlikely that someone will call the function with a Vector{None}.

[gitfoxi]

So, before there was not one single test for gradient. Just glancing at
the code if n > 0 short circuits the rest of the function which is broken
anyway. I'm not suggesting to go all corporate, but if I were the product
manager for JuliaLang I would freeze all new features until there was some
minimal test coverage for every existing one and then require coverage for
anything going to master going forward.

On Tue, Jan 7, 2014 at 7:35 AM, Andreas Noack Jensen <
[email protected]> wrote:

This one should also work for empty vectors except if they of type None.
I think it is unlikely that someone will call the function with a
Vector{None}.

—
Reply to this email directly or view it on GitHubhttps://github.com//pull/5321#issuecomment-31747362
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Michael

[JeffBezanson]

I'm pretty sure we already do require test coverage for all new features. The gradient function is probably very old.

[andreasnoack]

Git suggests that it dates back from 2012-04-21 so I think it is one of the older functions in linalg.