Turn on Harmony mode -- how do I do that in order to run ReactJS v0.13?

Question

I am following this comment where I am told to turn on harmony mode in order to use destructing assignments for ReactJS v0.13.

I have googled around and cannot find a good answer on how to turn this on.

If turning on Harmony mode is a bad idea, what is the highest version for ReactJS I must use instead?

UPDATE development workflow will either use grunt or gulp.

Answer 1

There isn't a single answer to your question as it depends on your development build workflow.

If you were using node-jsx npm package for example:

require('node-jsx').install({harmony: true});

If you used the command line compiler:

JSX filename -harmony

There is a solution for webpack, grunt, etc.

WebPack for example uses a loader flag:

// webpack.config.js
module.exports = {
  entry: './main.js',
  output: {
    filename: 'bundle.js'       
  },
  module: {
    loaders: [
      { test: /\.jsx$/, loader: 'jsx-loader?harmony' }
    ]
  },
  resolve: {
    // you can now require('file') instead of require('file.jsx')
    extensions: ['', '.js', '.json', '.jsx'] 
  }
};

There's an option for gulp that works like this:

var gulp = require('gulp');
var react = require('gulp-react');

gulp.task('default', function () {
    return gulp.src('template.jsx')
        .pipe(react({harmony: true}))  // enable harmony features
        .pipe(gulp.dest('dist'));
});