Oh dear God, I have decided to try and learn me some React now. I am starting with this tutorial – http://teropa.info/blog/2015/09/10/full-stack-redux-tutorial.html – which is itself a year and half old, so who knows if I’ll manage it. At any rate, it’s worth writing down some basic concepts.


NPM/Yarn uses the packages.json file to understand CLI commands. For example, the CLI command (henceforth, simply, “command”) npm run expects to see a “packages" key in the JSON file, like so:

"scripts": {
 "test": "mocha --compilers js:babel-core/register --recursive"

Sublime Text

You might be using Sublime. At this point, I am too, though I am more of an Emacs kind of guy. I could use Emacs 24.4’s electric-pair-mode for auto-parenthesis completion but I don’t know what package/mode can help with JSX files. In Sublime, you will need to download some packages to handle this – ReactJS, at least, perhaps others. I think you also need to install an NPM package.


This of course can get very large, but I like noting down things that I learn “bottom-up” – when odd error messages show me non-intuitive architectural behavior.

  1. When generating lists of components in React, via an iterator like map, each element of the produced list must have an attribute named precisely key. (See the ReactJS documentation on Keys.)