Gulp file for building the projects

gulpfile.js

const {src,dest,parallel,series,watch}= require('gulp');
const browserSync = require('browser-sync').create();
const sass = require('gulp-sass');
const concat = require('gulp-concat');
const uglify = require('gulp-uglify');
const autoprefixer=require('gulp-autoprefixer');
const cleanCSS=require('gulp-clean-css');
const imagemin= require('gulp-imagemin');
const notify= require('gulp-notify');
const del = require('del');

function serverTask() {
   browserSync.init({
      server: {
         baseDir: "./src"
      },
      notify:false
   });}
function sassTask () {
   return src('src/sass/**/*.sass')
       .pipe(sass().on("error",notify.onError()))
       .pipe(sass())
       .pipe(autoprefixer(['last 15 version']))
       .pipe(cleanCSS({compatibility:'ie8'}))
       .pipe(dest('src/css'))
       .pipe(browserSync.reload({stream:true}))
}
function imagesTask(){
   return src('src/img/**/*')
       .pipe(imagemin([imagemin.optipng({optimizationLevel:5})]))
       .pipe(dest('dist/img'))
}
function watchTask(){
   watch('src/sass/**/*.sass',parallel(sassTask));
   watch('src/img/**/*',browserSync.reload);
   watch('src/js/**/*.js',parallel(scriptsTask));
   watch('src/**/*.html',browserSync.reload);
}
function scriptsTask() {
   return src(['src/js/scripts.js'])
       .pipe(concat('script.min.js'))
       .pipe(uglify())
       .pipe(dest('src/js'))
       .pipe(browserSync.reload({
          stream: true
       }))
}
function delTask (){
   return del(['dist']);
}
function  buildTask() {
   return src([
       'src/**/*.html',
       'src/**/*.min.js',
       'src/**/*css'
   ])
   .pipe(dest('dist'))
}
exports.del=delTask;
exports.scripts=scriptsTask;
exports.sass=sassTask;
exports.images=imagesTask;
exports.watch=watchTask;
exports.server=serverTask;

exports.build=series(delTask,scriptsTask,sassTask,imagesTask,buildTask);
exports.default=parallel(serverTask,watchTask);