gulpfile.js

// Initialize modules
// Importing specific gulp API functions lets us write them below as series() instead of gulp.series()
const { src, dest, watch, series, parallel } = require('gulp');
// Importing all the Gulp-related packages we want to use
const sourcemaps = require('gulp-sourcemaps');
const sass = require('gulp-sass');
const concat = require('gulp-concat');
const postcss = require('gulp-postcss');
const autoprefixer = require('autoprefixer');
const cssnano = require('cssnano');
const terser = require('gulp-terser');
var babel = require("gulp-babel");
var replace = require('gulp-replace');

// File paths
const files = {
    scssPath: 'css/*.scss',
    jsPath: 'js/*.js'
}

// Sass task: compiles the style.scss file into style.css
function scssTask(){
    return src(files.scssPath)
        .pipe(sourcemaps.init()) // initialize sourcemaps first
        .pipe(sass()) // compile SCSS to CSS
        .pipe(concat('good-share.min.css')) //rename file
        .pipe(postcss([ autoprefixer(), cssnano() ])) // PostCSS plugins
        //.pipe(sourcemaps.write('.')) // write sourcemaps file in current directory
        .pipe(dest('dist')
    ); // put final CSS in dist folder
}

// JS task: concatenates and uglifies JS files to script.js
function jsTask(){
    return src(files.jsPath)
        .pipe(babel({
            presets: ['@babel/preset-env']
        }))
        .pipe(concat('good-share.min.js'))
        .pipe(terser()) //uglify
        .pipe(dest('dist')
    );
}

// Watch task: watch SCSS and JS files for changes
// If any change, run scss and js tasks simultaneously
function watchTask(){
    watch([files.scssPath, files.jsPath],
        parallel(scssTask, jsTask));
}

// Export the default Gulp task so it can be run
// Runs the scss and js tasks simultaneously
// then runs cacheBust, then watch task
exports.default = series(
    parallel(scssTask, jsTask),
    watchTask
);