gulpfile.js

const gulp = require('gulp');
const concat = require('gulp-concat');
const notify = require('gulp-notify');
const browserSync = require('browser-sync');
const jshint = require('gulp-jshint');

const paths = {
  assets: ['./src/assets/'],
  scripts: ['./src/js/main.js', './src/**/*.js'],
  html: ['./src/html/*.html', './src/html/index.html'],
  styles: ['./src/css/styles.css', './src/css/*.css']
};

gulp.task('serve', function() {
  browserSync.init({
    server: {
      baseDir: './public'
    }
  });
});

gulp.task('js:lint', function() {
  return gulp
    .src(paths.scripts)
    .pipe(jshint())
    .pipe(jshint.reporter('jshint-stylish'))
    .pipe(notify({ message: 'jshint done' }));
});

gulp.task('js:build', function() {
  return gulp
    .src(paths.scripts)
    .pipe(concat('main.js'))
    .pipe(gulp.dest('./public/js'))
    .pipe(notify({ message: 'JS concated' }));
});

gulp.task('js:watch', ['js:build'], function(done) {
  browserSync.reload();
  done();
});

gulp.task('html:build', function() {
  return gulp
    .src(paths.html)
    .pipe(gulp.dest('./public/'))
    .pipe(notify({ message: 'HTML pages built' }));
});

gulp.task('html:watch', ['html:build'], function(done) {
  browserSync.reload();
  done();
});

gulp.task('css:build', function() {
  return gulp
    .src(paths.styles)
    .pipe(concat('styles.css'))
    .pipe(gulp.dest('./public/css'))
    .pipe(notify({ message: 'CSS done' }));
});

gulp.task('css:watch', ['css:build'], function(done) {
  browserSync.reload();
  done();
});

gulp.task('build', ['html:build', 'js:build', 'css:build']);

gulp.task('watch', function() {
  gulp.watch(paths.html, ['html:watch']);
  gulp.watch(paths.scripts, ['js:lint', 'js:watch']);
  gulp.watch(paths.styles, ['css:watch']);
});

gulp.task('default', ['build', 'serve', 'watch']);