This lesson will utilize the Istanbul tool to instrument our code for code coverage recording and reporting. We'll use this to make sure that as our library gets new features, we keep track of our coverage and can find places to improve it.
If you are getting: error: No coverage information was collected, exit without writing coverage information when running istanbul, try to install istanbul@1.0.0-alpha.2 instead, as was suggested here: https://github.com/gotwarlost/istanbul/issues/262