How to set React to production mode when using Gulp

Question

I need to run React in production mode, which presumably entails defining the following somewhere in the enviornment:

process.env.NODE_ENV = \'production\';
         


        

Answer 1

Similar to the other answers, but hopefully gives someone a starting point:

var vendorList = ['react', 'react-dom'];

gulp.task('vendor-dev', function() {
    browserify()
        .require(vendorList)
        .bundle()
        .on('error', handleErrors)
        .pipe(source('vendor.js'))
        .pipe(gulp.dest('./build/dev/js'));
});

gulp.task('vendor-production', function() {
    process.env.NODE_ENV = 'production';
    browserify()
        .require(vendorList)
        .bundle()
        .on('error', handleErrors)
        .pipe(source('vendor.js'))
        .pipe(buffer())
        .pipe(uglify({ mangle: false }))
        .pipe(gulp.dest('./build/production/js'));
});

The main difference is I am explicitly setting the NODE_ENV prior to bundling the vendor libraries. Gulp tasks aren't guaranteed to run in order.

Am I running in production mode?

If you remove the uglify line (and prior buffer) you will notice that both the dev and production builds are near identical in size - and match in line count.

The difference is the production version will be littered with:

"production" !== "production" ? [show dev error] : [no nothing]

Most reputable minify'ers (I believe) will strip out deadend code, such as the above, which will always result in false.

But really how do I tell?

Easiest method to be sure, would be goto the console of your running application and type:

React.createClass.toString();

The output should be:

"function (e){var t=function(e,t,n){this.__reactAutoBindMap&&c(this),"[....and more and more]

If you find the createClass in the react source, you will see:

createClass: function (spec) {
    var Constructor = function (props, context, updater) {
      // This constructor is overridden by mocks. The argument is used
      // by mocks to assert on what gets mounted.

      if ("production" !== 'production') {
        "production" !== 'production' ? warning(this instanceof Constructor, 'Something is calling a React component directly. Use a factory or ' + 'JSX instead. See: react-legacyfactory') : undefined;
      }

      // Wire up auto-binding
      if (this.__reactAutoBindMap) {
        bindAutoBindMethods(this);
      }

Notice how the console output skips straight through to this.__reactAutobind, because you are running in production mode, and using an minify'er, all the !== 'production' warngins and checks have been skipped over.