features

per-file switchable code pre-transformations

Usage no npm install needed!

<script type="module">
  import features from 'https://cdn.skypack.dev/features';
</script>

README

Switchable, modular, stackable features for your code. Turn on any transformations you'd like to use.

Usage example:

[jann@Jann-PC tmp]$ cat test.xjs
// :X-FEATURE: destructure

var a, b, c;
var val = [{x: 5, y: 6}, 7];
[{x: a, y: b}, c] = val;
console.log('how it should be: a=5='+a+', b=6='+b+', c=7='+c);
[jann@Jann-PC tmp]$ node
> require('features')
{}
> require('./test')
how it should be: a=5=5, b=6=6, c=7=7
{}

So, basically, for people who want to use such features:

  • install feature-<name> modules for the features you want
  • use .xjs as file extension
  • in your main script, do this on top: require('features')
  • in your scripts, put lines like this one ON TOP (no lines, even no empty ones, may be on top of them): // :X-FEATURE: destructure

Note that your main script can't use such features - you might want to use a shim script.

Also note that although this module should just work, the destructure feature doesn't do some important things as of 15.01.2012 (most importantly, caching results).

For people who want to make features:

  • make a new npm package named feature-<name>
  • in its main file, add a function transformCodeString(code) to the exports

See https://github.com/thejh/node-feature-destructure/ for an example.