gulpfile.js

var gulp = require('gulp');

var jade = require('gulp-jade'),
    uglify = require('gulp-uglify'),
    concat = require('gulp-concat'),
    plumber = require('gulp-plumber'),
    sass = require('gulp-sass'),
    imagemin = require('gulp-imagemin');

var paths = {
  templates: {
    src:  'client/templates/*.jade',
    dest: 'build/html'
  },
  scripts: {    
    src:  'client/assets/js/**/*.js',
    dest: 'build/assets/js'
  },
  styles: {
    src:  'client/assets/css/**/*.scss',
    dest: 'build/assets/css'
  },
  images: {
   src:  'client/assets/img/**/*',
   dest: 'build/assets/img'
  }
};



gulp.task('templates', function() {
  return gulp.src(paths.templates.src)
    .pipe(jade())
    .pipe(gulp.dest(paths.templates.dest))
});

gulp.task('scripts', function() {
  // Minify and copy all JavaScript (except vendor scripts)
  return gulp.src(paths.scripts.src)
    .pipe(uglify())
    .pipe(concat('all.min.js'))
    .pipe(gulp.dest(paths.scripts.dest));
});

gulp.task('styles', function () {
  return gulp.src(paths.styles.src)
    .pipe(plumber())
    .pipe(sass())
    .pipe(gulp.dest(paths.styles.dest));
});

// Copy all static images
gulp.task('images', function() {
  return gulp.src(paths.images.src)
    // Pass in options to the task
    .pipe(imagemin({optimizationLevel: 5}))
    .pipe(gulp.dest(paths.images.dest));
});



// Rerun the task when a file changes
gulp.task('watch', function() {
  gulp.watch(paths.templates.src, ['templates']);
  gulp.watch(paths.scripts.src, ['scripts']);
  gulp.watch(paths.styles.src, ['styles']);
  gulp.watch(paths.images.src, ['images']);
});

// The default task (called when you run `gulp` from cli)
gulp.task('default', ['templates', 'scripts', 'styles', 'images', 'watch']);