gulpfile.js

var gulp = require('gulp');
var browserify = require('browserify');
var reactify = require('reactify');
var del = require('del');
var source = require('vinyl-source-stream');
var sass = require('gulp-sass');
var sourcemaps = require('gulp-sourcemaps')

var paths = {
  SCSS: ['app/css/**/*.scss'],
  JSX: ['./app/js/App.jsx'],
};

gulp.task('clean', function(done) {
  del(['build'], done);
});

gulp.task('scss', ['clean'], function() {
  return gulp.src(paths.SCSS)
    .pipe(sourcemaps.init())
      .pipe(sass().on('error', sass.logError))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest('./app/build'));
});

gulp.task('jsx', ['clean'], function() {
  browserify(paths.JSX, { debug: true })
    .transform(reactify, { es6: true })
    .bundle()
    .pipe(source('bundle.js'))
    .pipe(gulp.dest('./app/build'));
});

gulp.task('build', ['scss', 'jsx']);

gulp.task('watch', function() {
  gulp.watch(paths.SCSS, ['scss']);
  gulp.watch(paths.JSX, ['jsx']);
});

gulp.task('default', ['build']);