gulpfile.js

/* eslint-disable one-var */
/* eslint-disable no-var */
'use strict';

var gulp = require('gulp'),
    concat = require('gulp-concat'),
    cssmin = require('gulp-clean-css'),
    htmlmin = require('gulp-htmlmin'),
    terser = require('terser'),
    gulpTerser = require('gulp-terser'),
    merge = require('merge-stream'),
    del = import('del'),
    bundleconfig = require('./bundleconfig.json');

const regex = {
    css: /\.css$/,
    html: /\.(html|htm)$/,
    js: /\.js$/
};

gulp.task('min:js', async function () {
    merge(getBundles(regex.js).map(bundle => {
        return gulp.src(bundle.inputFiles, { base: '.' })
            .pipe(concat(bundle.outputFileName))
            .pipe(gulpTerser({}, terser.minify))
            .pipe(gulp.dest('.'));
    }));
});

gulp.task('min:css', async function () {
    merge(getBundles(regex.css).map(bundle => {
        return gulp.src(bundle.inputFiles, { base: '.' })
            .pipe(concat(bundle.outputFileName))
            .pipe(cssmin())
            .pipe(gulp.dest('.'));
    }));
});

gulp.task('min:html', async function () {
    merge(getBundles(regex.html).map(bundle => {
        return gulp.src(bundle.inputFiles, { base: '.' })
            .pipe(concat(bundle.outputFileName))
            .pipe(htmlmin({ collapseWhitespace: true, minifyCSS: true, minifyJS: true }))
            .pipe(gulp.dest('.'));
    }));
});

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

gulp.task('clean', () => {
    return del(bundleconfig.map(bundle => bundle.outputFileName));
});

gulp.task('watch', () => {
    getBundles(regex.js).forEach(
        bundle => gulp.watch(bundle.inputFiles, gulp.series(['min:js'])));

    getBundles(regex.css).forEach(
        bundle => gulp.watch(bundle.inputFiles, gulp.series(['min:css'])));

    getBundles(regex.html).forEach(
        bundle => gulp.watch(bundle.inputFiles, gulp.series(['min:html'])));
});

const getBundles = (regexPattern) => {
    return bundleconfig.filter(bundle => {
        return regexPattern.test(bundle.outputFileName);
    });
};

gulp.task('default', gulp.series('min'));