ADD: Testing documentation

[VladimirMikulic]

Testing is described in a new TESTING.md file.
I've also added grunt test to the test NPM script.

Resolves #506

@cesswairimu could you take a look at this? Thanks.

[jywarren]

This is really lovely. Wonderful work! cc @sashadev-sky @rexagod 🎉 💯

[jywarren]

Oh sorry @cesswairimu i just got excited!

cc @crisner @sagarpreet-chadha this is such a good documentation section on testing. take a look! 👀

[VladimirMikulic]

Thank you very much @jywarren!

[crisner]

This is great! Love the documentation. Amazing work @VladimirMikulic!

[VladimirMikulic]

Thanks @crisner.

[cesswairimu]

Amazing 🚀

[VladimirMikulic]

I appreciate it @cesswairimu.

[sashadev-sky]

Just checked this out thank you so much!! @VladimirMikulic

$ mocha <filename>.js doesn't work for me even after installing it globally. It doesn't recognize L (leaflet) as a context and after I managed to get that working by passing in some extra options it doesn't recognize chai from the specHelper.js file. Any clue what I'm missing?

[VladimirMikulic]

@sashadev-sky my mistake. I've noticed that we don't manually require modules in our tests.
In order for this to work, we should require chai in the test files, the same goes for L and other modules(browser's window object also).

That's one way of doing it. The other one is to wrap the code of the test file in one describe.only() block and then run npm test which will run only that test file.

How should I update this? Thanks.

[sashadev-sky]

@VladimirMikulic no problem! not a big deal. I'm not sure we can use require outside of the Gruntfile could be wrong? If we can't fix it the 1st way we can just update the readme to say the 2nd one! Thank you!

[VladimirMikulic]

@sashadev-sky we can use require outside of Gruntfile.