Sample of gulpfile.js

gulpfile.js

var gulp = require('gulp'),
  sass = require('gulp-sass'),
  concat = require('gulp-concat'),
  sourcemaps = require('gulp-sourcemaps'),
  imagemin = require('gulp-imagemin'),
  livereload = require('gulp-livereload'),
  autoprefixer = require('gulp-autoprefixer'),
  notify = require("gulp-notify"),
  del = require('del');


gulp.task('clean-styles', function() {
  return del(['wp/wp-content/themes/theme-name/css/']);
});

gulp.task('styles', function() {
  return gulp.src('src/scss/main.scss')
    .pipe(sourcemaps.init())
    .pipe(sass({
      style: 'expanded'
    }).on('error', sass.logError))
    .pipe(autoprefixer({
      browsers: ['last 2 versions']
    }))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest('wp/wp-content/themes/theme-name/css/'))
    .pipe(notify({
      message: 'Styles task complete'
    }));
});


gulp.task('clean-scripts', function() {
  return del(['wp/wp-content/themes/theme-name/js/']);
});
gulp.task('scripts', function() {
  console.log('called scripts-compile');
  return gulp.src('src/js/**/*.js')
    .pipe(concat('main.js'))
    .pipe(gulp.dest('wp/wp-content/themes/theme-name/js/'));
});

gulp.task('clean-images', function() {
  return del(['wp/wp-content/themes/theme-name/img/']);
});
gulp.task('images', function() {
  console.log('called images');
  return gulp.src('src/img/**/*')
    .pipe(
        imagemin(
          [
            imagemin.gifsicle({
              interlaced: true
            }),
            imagemin.jpegtran({
              progressive: true
            }),
            imagemin.optipng({
              optimizationLevel: 5
            }),
            imagemin.svgo({
              plugins: [{
                removeViewBox: true
              }, {
                cleanupIDs: false
              }]
            })
          ], {
            verbose: true
          }
        )
    )
    .pipe(gulp.dest('wp/wp-content/themes/theme-name/img/'))
    .pipe(notify({
      message: "Images Done!",
      onLast: true
    }));
});


gulp.task('copy-config', function() {
  return gulp.src([
    'src/wp-config.php',
    'src/.htaccess'
    ]).pipe(gulp.dest('wp/'));
});

gulp.task('copy-theme', function() {
  console.log('called copy-theme');
  return gulp.src('src/theme/theme-name/**')
    .pipe(gulp.dest('wp/wp-content/themes/theme-name/'))
    .pipe(notify({
      message: "Theme copied!",
      onLast: true
    }));
});


gulp.task('clean-all', ['clean-styles', 'clean-scripts', 'clean-images']);
gulp.task('build-all', ['styles', 'scripts', 'images']);
gulp.task('copy-all', ['copy-config', 'copy-theme']);


gulp.task('init', ['clean-all', 'build-all', 'copy-all']);



gulp.task('default', ['build-all', 'copy-theme'], function() {

  gulp.watch('src/scss/**/*.scss', ['styles']);

  gulp.watch('src/js/**/*.js', ['scripts']);

  gulp.watch('src/img/**/*', ['images']);

  gulp.watch('src/theme/theme-name/**/*.php', ['copy-theme']);


  livereload.listen();

  gulp.watch(['wp/wp-content/themes/theme-name/**']).on('change', livereload.changed);


});