Application has automated tests built with Jest. Run all tests:
npm test
I haven't ever coded a calculator, which usually is one of the most common exercises for programmers. To fix this, I did a challenge to try and write a calculator in Javascript in 1 day. Here's what came out at the end of the day.
Writing regular expressions took some time. In my opinion, logic I implemented was straightforward.
On second day added unit tests and wrote another feature, calculator supports non whole numbers and hopefully will get new UI soon.
Added keyboard support.