An example of a long gulpfile

Long gulpfile.js

var gulp = require('gulp');
var util = require('gulp-util');
var browserSync = require('browser-sync').create();
var sourcemaps = require('gulp-sourcemaps');
var rename = require('gulp-rename');

var sass = require('gulp-sass');
var minifyCss = require('gulp-minify-css');

var browserify = require('gulp-browserify');
var reactify = require('reactify');
var jshint = require('gulp-jshint');
var uglify = require('gulp-uglify');

var spritesmith = require('gulp.spritesmith');
var merge = require('merge-stream');

var paths = {
    scss: {
        source: 'resources/scss/**/*.scss',
        dest: 'assets/css'
    },
    js: {
        source: 'app/index.js',
        watch: 'app/**/*.js',
        dest: 'assets/js'
    }
};

gulp.task('default', ['scss', 'js']);

gulp.task('watch', function() {
    gulp.watch(paths.scss.source, ['scss']);
    gulp.watch(paths.js.watch, ['js']);

    browserSync.init({
        open: false,
        server: {
            baseDir: "./"
        }
    });
});

gulp.task('scss', function() {
    return gulp.src(paths.scss.source)
        .pipe(!util.env.production ? sourcemaps.init() : util.noop())
        .pipe(sass())
        .pipe(!util.env.production ? sourcemaps.write() : util.noop())
        .pipe(util.env.production ? minifyCss() : util.noop())
        .pipe(rename('style.css'))
        .pipe(gulp.dest(paths.scss.dest))
        .pipe(browserSync.reload({
            stream: true
        }));
});

gulp.task('js', function() {
    return gulp.src(paths.js.source)
        .pipe(!util.env.production ? sourcemaps.init() : util.noop())
        .pipe(jshint())
          .pipe(jshint.reporter('default'))
          .pipe(browserify({
             transform: ['reactify'],
             insertGlobals : true,
             debug : !util.env.production
        }))
        .pipe(uglify())
        .pipe(!util.env.production ? sourcemaps.write() : util.noop())
        .pipe(rename('script.js'))
        .pipe(gulp.dest(paths.js.dest))
        .pipe(browserSync.reload({
            stream: true
        }));
});

gulp.task('sprite', function() {
  var spriteData = gulp.src('resources/img/flags').pipe(spritesmith({
        imgName: 'flags.png',
        imgPath: 'img',
        cssName: 'temp.css',
        cssOpts: {
            cssSelector: function(item) {
                return '.flag.flag-' + item.name;
            }
        }
    }));

    var imgStream = spriteData.img
        .pipe(gulp.dest('assets/img'));

    var cssStream = spriteData.css
        .pipe(rename('flags.css'))
        .pipe(gulp.dest('assets/css'));

    return merge(imgStream, cssStream);
});