- Extend - http://underscorejs.org/#extend
- Once - http://underscorejs.org/#once
- Delay - http://underscorejs.org/#delay
- Memoize - http://underscorejs.org/#memoize
Without a solid knowledge of these topics you will have a very hard time implementing these methods.
- What these underscore methods do!
- setTimeout / setInterval
- Closures http://javascriptissexy.com/understand-javascript-closures-with-ease/
- Call/Apply http://javascriptissexy.com/javascript-apply-call-and-bind-methods-are-essential-for-javascript-professionals/
- Fork and Clone the repo and then run npm install to make sure you pull in Mocha, Chai and Sinon.
- First, start with some research, make sure you know exactly what these five functions do before you try to implement them on your own.
- Try to make the tests pass
This is one of the most if not the most difficult JS challenge. Be prepared to do a large amout of research if you want to be successful.