Add mocha tests

[manuasir]

Hi, it'd be great this script could have mocha tests.

[chrishutchinson]

I'm happy to pitch in here @manuasir? To make the testing easier, I also propose we separate out the functions from your index.js file into separate files.

I'd also propose we use Jest as the testing framework over Mocha, as it has a better mocking feature set, and brings the assertion library too (whereas with Mocha you usually have to add Chai too). If you'd prefer Mocha that's not a problem, but I suspect your tests will be cleaner in Jest!

If you're happy I will go ahead with this 👍

[manuasir]

Sure @chrishutchinson ! Thanks.

[manuasir]

This issue is still available.