Al Scott is an Emacs user and JavaScript developer who’s interested in using the TDD method. He likes to use Mocha to run JavaScript scripts for testing. Unfortunately, there’s no easy way to do that from Emacs so Scott decided to write a custom package, tied to the Emacs compile command, that would implement a Mocha test runner. His post walks us through the steps needed to write such a package.
Scott starts by noting that Emacs comes with a lot of built-in facilities to ease Elisp development and that by adding a couple of packages like flycheck and company-mode you have a pretty complete IDE for Elisp. The purpose of his Mocha-runner is to bring some of the same capabilities to JavaScript development.
The rest of the post shows the step by step development of writing the package. He even mentions the steps needed to add the package to the MELPA package repository. Even if you’re not a JavaScript developer or interested in TDD, there’s a lot of useful information in the post and I recommend it to any Elisp developer.