gulpfile.js

const gulp = require('gulp');
const terser = require('gulp-terser');
const cleancss = require('gulp-clean-css');
const jsonminify = require('gulp-jsonminify');


// The src() and dest() methods are exposed by gulp to interact with files on your computer.
function jsMinifyTask(cb) {
    return gulp.src(['js/main.js', 'js/editions.js']) // (['./js/client.js', './js/animation.js']) // ignore pattern  '!js/*.min.js'
        .pipe(terser())
        .pipe(gulp.dest('./build/js'));
}

function cssMinifyTask(cb) {
    return gulp.src(['css/bootstrap.min.css', 'css/styles.css'])
        .pipe(cleancss({compatibility: 'ie8'}))
        .pipe(gulp.dest('./build/css'));
}

function copyTypeaheadLibsTask(cb) {
    return gulp.src(['js/typeahead/typeahead.bundle.min.js'])
        .pipe(gulp.dest('./build/js/typeahead'));
}

function copySupportsLibsTask(cb) {
    return gulp.src(['js/bootstrap.bundle.min.js', 'js/jquery-3.5.1.min.js'])
        .pipe(gulp.dest('./build/js'));
}

function copyHtmlTask(cb) {
    return gulp.src('index.html')
        .pipe(gulp.dest('./build'));
}

function copyAssetsTask(cb) {
    return gulp.src('assets/*.*')
        .pipe(gulp.dest('./build/assets'));
}


function jsonMinifyTask(cb) {
    return gulp.src('cards/*.json')
        .pipe(jsonminify())
        .pipe(gulp.dest('./build/cards'));
}

function emptyTask(cb) {
    // place code for your default task here
    cb(); // use the callback function if you are not returning data
}

//exports.default = gulp.series(emptyTask, minifyTask);
exports.default = gulp.parallel(emptyTask, jsMinifyTask, cssMinifyTask, jsonMinifyTask,
    copyHtmlTask, copyAssetsTask, copySupportsLibsTask, copyTypeaheadLibsTask);