auto-babel

auto-babel is a project that aims to bring autoprefixer-like functionality to babel.

Word of warning

Use with caution: the tests run (es-feature-tests) aren't indicate of perfect spec compliance.

Using auto-babel

auto-babel outputs a list of transformers to blacklist based on feature support. For example, if all the browsers and environments you target support let and const, you don't need to run the es6.blockScoping transpiler.

API

var autoBabel = require('auto-babel');

var blacklistedTransformers = autoBabel('last 2 versions', '> 0.12.7');
babel.transform(code, { blacklist: blacklistedTransformers });

CLI

 ./cli.js -e 'last 2 Chrome versions' -n '> 0.12.7'
 
  [ 'es6.blockScoping',
    'es6.constants',
    'es6.spec.blockScoping',
    'es6.spec.symbols',
    'es6.spec.templateLiterals',
    'es6.templateLiterals',
    'regenerator' ]

Running the tests

Environment setup

Install the grunt command line tool

npm install grunt-cli -g

Install project dependencies

npm install

node/iojs tests

Run the tests

make run-node

Files are output to "build/results" in json format

Browser tests

The browser tests are run using sauce labs so all tests can be run from a single computer.

1 - Add sauce labs credentials.

    export SAUCE_USERNAME=$USERNAME
    export SAUCE_ACCESS_KEY=$KEY

2 - Set up sauce connect tunnel

    node_modules/sauce-tunnel/vendor/linux/bin/sc -D featuretests.io

3 - Run the tests

    make run-browser

Process results

node processResults.js creates/updates the data.json file used at runtime.