gulpfile.js

var RX = require('reactxp'); // I tried import, but it threw an error when on `gulp run`, so var seemed to work
var gulp = require('gulp');

var config: { // I get "SyntaxError: Unexpected token :" on `gulp run`
    aliasify: {
        src: './.temp/' + RX.Platform.getType(),
        dest: getBuildPath() + 'js/',
        aliases: (RX.Platform.getType() === 'web') ?
        // Web Aliases
        {
            'AppAssets': './src/modules/AppAssetsWeb'
        } :
        // Native Aliases
        {
            'AppAssets': './src/modules/AppAssetsNative'
        }
    }
}

function aliasify(aliases) {
    var reqPattern = new RegExp(/require\(['"]([^'"]+)['"]\)/g);

    // For all files in the stream, apply the replacement.
    return eventStream.map(function(file, done) {
        if (!file.isNull()) {
            var fileContent = file.contents.toString();
            if (reqPattern.test(fileContent)) {
                file.contents = new Buffer(fileContent.replace(reqPattern, function(req, oldPath) {
                    if (!aliases[oldPath]) {
                        return req;
                    }

                    return "require('" + aliases[oldPath] + "')";
                }));
            }
        }

        done(null, file);
    });
}

gulp.task('apply-aliases', function() {
    return gulp.src(path.join(config.aliasify.src, '**/*.js'))
        .pipe(aliasify(config.aliasify.aliases))
        .pipe(gulp.dest(config.aliasify.dest))
        .on('error', handleError);
});

// Here's our full build task pipeline. I haven't provided the task
// definitions for all of these stages, but you can see where the
// 'apply-aliases' task fits into the pipeline.
gulp.task('run', function(callback) {
    runSequence('clean', 'build', 'apply-aliases', 'watch', 'lint');
});