General every day use gulp file

gulpfile.js

var gulp = require('gulp');
var uglify = require('gulp-uglify');
var sass = require('gulp-ruby-sass');
var livereload = require('gulp-livereload');
var imagemin = require('gulp-imagemin');
var prefix = require('gulp-autoprefixer');

function errorLog(error) {
  console.error.bind(error);
  this.emit('end');
}

// minimize js
gulp.task('scripts', function(){
  gulp.src('js/*.js')
  .pipe(uglify())
  .on('error', errorLog)
  .pipe(gulp.dest('build/js'))
});


// Watch Task
gulp.task('watch', function(){
  livereload.listen();
  gulp.watch('js/*.js', ['scripts']);
  gulp.watch('scss/**/*.scss', ['styles']);
  gulp.watch('./*.html', ['html'])
});


// html reload
gulp.task('html', function(){
  gulp.src('./*.html')
  .pipe(livereload())
});

// sass compile, reload and prefix css
gulp.task('styles', function(){
  return sass('scss/**/*.scss', {style: 'compressed'})
  .on('error', errorLog)
  .pipe(prefix('last 2 versions'))
  .pipe(gulp.dest('css/'))
  .pipe(livereload())
});

// compress images (not part of default task)
gulp.task('image', function(){
  gulp.src('img/**/*')
  .pipe(imagemin())
  .pipe(gulp.dest('build/img'));
})


gulp.task('default', [ 'styles', 'html', 'watch' ]);

// kill -9 $(lsof -t -i :35729)