Sample Gulp setup. Watches JS to JSHint, watches two themes for Sass+Compass compilation.

gulpfile.js

/**
 * @file
 *   Gulpfile that controls frontend development tasks. Just the basics!
 * 
 * Installation: type `npm install` in your console.
 * Usage: type `gulp` in your console.
 */

/* jslint node: true */
'use strict';

// Declare dependencies
var gulp = require('gulp');
var compass = require('gulp-compass');
var jshint = require('gulp-jshint');
var prefix = require('gulp-autoprefixer');

// Task: Compass - theme_one
gulp.task('compass-theme_one', function() {
  gulp.src('sites/all/themes/theme_one/sass/*.scss')
  .pipe(compass({
    bundle_exec: true,
    config_file: 'sites/all/themes/theme_one/config.rb',
    css: 'sites/all/themes/theme_one/css',
    sass: 'sites/all/themes/theme_one/sass',
    image: 'sites/all/themes/theme_one/img'
  }))
  .pipe(prefix("last 2 versions", "> 1%"))
  .pipe(gulp.dest('sites/all/themes/theme_one/css'));
});

// Task: Compass - theme_two
gulp.task('compass-theme_two', function() {
  gulp.src('sites/all/themes/theme_two/sass/*.scss')
  .pipe(compass({
    bundle_exec: true,
    config_file: 'sites/all/themes/theme_two/config.rb',
    css: 'sites/all/themes/theme_two/css',
    sass: 'sites/all/themes/theme_two/sass',
    image: 'sites/all/themes/theme_two/img'
  }))
  .pipe(prefix("last 2 versions", "> 1%"))
  .pipe(gulp.dest('sites/all/themes/theme_two/css'));
});

// Task: JSHint
gulp.task('lint', function() {
  gulp.src('sites/all/**/js/*.js')
    .pipe(jshint())
    .pipe(jshint.reporter('default'));
});

// Task: Watch
gulp.task('watch', ['compass-theme_one', 'compass-theme_two', 'lint'], function () {
  gulp.watch(['sites/all/themes/theme_one/sass/**/*.scss'], ['compass-theme_one']);
  gulp.watch(['sites/all/themes/theme_two/sass/**/*.scss'], ['compass-theme_two']);
  gulp.watch(['sites/all/**/*.js'], ['lint']);
});

// Default: Watch
gulp.task('default', ['watch']);

package.json

{
  "name": "gulp-sample-setup",
  "description": "Sample Gulp setup",
  "version": "0.X.0",
  "dependencies": {},
  "devDependencies": {
    "gulp": "~3.8.0",
    "gulp-autoprefixer": "0.0.7",
    "gulp-compass": "^1.1.9",
    "gulp-jshint": "^1.6.2"
  }
}