A script to compile .js and .jsx to es6 with Babel using babel-core, that actually works!
npm install babel-compilerm -rf out/ to makeThe result is a babel cli client which does things the way we want:
* Automatically generate source maps with correct file references
* Cleans output directory
* Allows us to load configuration from an NPM module instead of copying around a .babelrc
npm install babel-compile --save-dev
npm install babel-preset-es2015 --save-dev
Next, you're going to want to add it to your file's scripts
section.Assuming that you store your code in
src/ and your tests in test/ and you
want them to respectively end up in lib/ and .test/, you could add the
following to your package.json:`json
...
"scripts": {
"compile": "babel-compile -p es2015 src:lib test:.test",
"pretest": "npm run compile",
"prepublish": "npm run compile"
}
...`Whenever you run
or npm publish, you will also have your code compiled
automatically. If you want to test your code, you can run npm run compile to get
a compiled copy.Tests
Mocha has a built in hook for comping code with babel as its imported. We
don't use this hook anymore as it could work around bugs correctly in tests
that aren't worked around in a deployed set of code. An example of problem
code is the Array.prototype shim methods like .include.When importing code from a babel-compiled library in your tests, ensure that
you
`
require('../lib/file');
to include the compiled copy for the program.As well, your package.json file's test script should use, as an example,
instead of test/_test.jsSource Maps (why do I have awful stack traces)
If you're using Node 0.12, you're likely noticing that your stack traces are terrible.
This is because the Node 0.12 environment doesn't support source maps natively.
If you'd like to have useful stacktraces, you can do this:
npm install source-map-support
and then, in your non-library js-code, add
require('source-map-support').install();