Example Gulpfile used on a legacy WordPress project

.bowerrc

{
  "directory": "vendor"
}

bower.json

{
  "name": "TEDxTheme",
  "version": "1.0.0",
  "homepage": "https://github.com/twg/TEDxTheme",
  "authors": [
    "Emerson Lackey & Bil Li"
  ],
  "license": "MIT",
  "private": true,
  "ignore": [
    "**/.*",
    "node_modules",
    "bower_components",
    "vendor",
    "test",
    "tests"
  ],
  "dependencies": {
    "bootstrap": "~3.1.1"
  }
}

Gulpfile.js

var gulp = require('gulp'),
    sass = require('gulp-sass'),
    livereload = require('gulp-livereload'),
    tinylr = require('tiny-lr'),
    autoprefixer = require('gulp-autoprefixer'),
    rename = require('gulp-rename'),
    notify = require('gulp-notify'),
    minifycss = require('gulp-minify-css'),
    jshint = require('gulp-jshint'),
    uglify = require('gulp-uglify'),
    clean = require('gulp-clean'),
    concat = require('gulp-concat');

//-- Bower Dependencies -----------------------------------------------------
var bowerJsDependencies = [
  './vendor/jquery/dist/jquery.js',
  './vendor/bootstrap/dist/js/bootstrap.js'
];
var bowerCssDependencies = [
  './vendor/bootstrap/dist/css/bootstrap.css'
];

//-- Compile SCSS -----------------------------------------------------------
gulp.task('styles', function() {
  return gulp.src('./assets/scss/*.scss')
    .pipe(sass({style: 'expand'}))
    .pipe(autoprefixer('last 2 version', 'safari 5', 'ie 8', 'ie 9', 'opera 12.1', 'ios 6', 'android 4'))
    .pipe(gulp.dest('./dist/css'))
    .pipe(rename({suffix: '.min'}))
    .pipe(minifycss())
    .pipe(gulp.dest('./dist/css'));
});


//-- Compile Javascripts ----------------------------------------------------
gulp.task('scripts', function() {
  return gulp.src('./assets/js/*.js')
    .pipe(jshint('.jshintrc'))
    .pipe(jshint.reporter('default'))
    .pipe(concat('application.js'))
    .pipe(gulp.dest('dist/js'))
    .pipe(rename({suffix: '.min'}))
    .pipe(uglify())
    .pipe(gulp.dest('dist/js/'));
});


//-- Merge and Minify Bower JS Dependencies ------------------------------------
gulp.task('vendor-js', function() {
  return gulp.src(bowerJsDependencies)
    .pipe(concat('vendor.js'))
    .pipe(gulp.dest('./dist/js'))
    .pipe(rename({suffix: '.min'}))
    .pipe(uglify())
    .pipe(gulp.dest('dist/js'));
});


//-- Merge and Minify Bower CSS Dependencies --------------------------------
gulp.task('vendor-css', function() {
  return gulp.src(bowerCssDependencies)
    .pipe(concat('vendor.css'))
    .pipe(gulp.dest('./dist/css'))
    .pipe(rename({suffix: '.min'}))
    .pipe(minifycss())
    .pipe(gulp.dest('dist/css'));
});


//-- Clean task to run before deploys ---------------------------------------
gulp.task('clean', function() {
  return gulp.src(['./dist/assets/css', './dist/assets/js'], {read: false})
    .pipe(clean());
});


//-- Default Task -----------------------------------------------------------
gulp.task('default', function() {
  gulp.start('styles', 'scripts', 'vendor-css', 'vendor-js');
});


//-- Watching & Livereload --------------------------------------------------
gulp.task('watch', function() {

  gulp.watch('./assets/scss/**/*.scss', ['styles']);
  gulp.watch('./assets/js/**/*.js', ['scripts']);

  livereload.listen();
  gulp.watch(['./dist/**', './**/*.php']).on('change', livereload.changed);

});

package.json

{
  "name": "TEDxTheme",
  "version": "1.0.0",
  "description": "A TEDx WordPress theme built by The Working Group (http://twg.ca) and TEDxToronto.",
  "main": "Gulpfile.js",
  "dependencies": {
    "gulp": "^3.7.0"
  },
  "devDependencies": {
    "gulp": "^3.7.0",
    "gulp-concat": "^2.2.0",
    "gulp-uglify": "^0.3.0",
    "gulp-livereload": "^2.0.0",
    "gulp-sass": "^0.7.2",
    "gulp-autoprefixer": "0.0.7",
    "gulp-notify": "^1.3.1",
    "gulp-clean": "^0.3.0",
    "gulp-minify-css": "^0.3.4",
    "gulp-jshint": "^1.6.2",
    "gulp-cache": "^0.1.11",
    "gulp-rename": "^1.2.0",
    "tiny-lr": "0.0.7"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git://github.com/twg/TEDxTheme.git"
  },
  "author": "Emerson Lackey & Bill Li",
  "license": "MIT",
  "bugs": {
    "url": "https://github.com/twg/TEDxTheme/issues"
  },
  "homepage": "https://github.com/twg/TEDxTheme"
}