Advanced gulp config

gulpfile.js

const gulp = require('gulp'),
    sass = require('gulp-sass'),
    postcss = require('gulp-postcss'),
    autoprefixer = require('autoprefixer'),
    mqpacker = require('css-mqpacker'),
    sourcemaps = require('gulp-sourcemaps'),
    debug = require('gulp-debug'),
    gulpIf = require('gulp-if'),
    del = require('del'),
    newer = require('gulp-newer'),
    browserSync = require('browser-sync').create(),
    notify = require('gulp-notify'),
    minify = require('gulp-csso'),
    multipipe = require('multipipe'),
    cssnano = require('gulp-cssnano'),
    rev = require('gulp-rev'),
    combine = require('stream-combiner2').obj,
    imagemin = require('gulp-imagemin'),
    ghPages = require('gulp-gh-pages'),
    rename = require('gulp-rename'),
    uglify = require('gulp-uglify'),
    babel = require('gulp-babel'),
    rollup = require('gulp-rollup'),
    svgstore = require('gulp-svgstore'),
    svgmin = require('gulp-svgmin'),
    path = require('path');


const isDevelopment = !process.env.NODE_ENV || process.env.NODE_ENV == "development";  // set NODE_ENV=production&&gulp build   (В консоль на продакшн(Сборка без sourcemaps))

gulp.task('styles', function () {

  return multipipe(
      gulp.src('src/sass/style.scss'),
      gulpIf(isDevelopment, sourcemaps.init()),
      sass(),
      postcss([
        autoprefixer({
          browsers: [
            'last 1 version',
            'last 2 Chrome versions',
            'last 2 Firefox versions',
            'last 2 Opera versions',
            'last 2 Edge versions'
          ]
        }),
        mqpacker({
          sort: true
        })
      ]),
      gulpIf(isDevelopment, sourcemaps.write()),
      gulp.dest('build/css'),
      minify(),
      rename('style-min.css'),
      debug({title: 'min-css'}),
      gulp.dest('build/css')
  ).on('error', notify.onError(function (err) {
    return {
      title: 'Styles',
      message: err.message
    };
  }));

});

gulp.task('min-js', function () {
  return multipipe(
      gulp.src('src/assets/js/app.js')
          .pipe(sourcemaps.init())
          .pipe(rollup({
            allowRealFiles: true,
            input: 'src/assets/js/app.js',
            format: 'umd',
          }))
          .pipe(babel({
            presets: ['env']
          }))
          .pipe(sourcemaps.write('.'))
          .pipe(gulp.dest('build/js'))
  );
});
gulp.task('clean', function () {
  return del('build');
});
gulp.task('images', function () {
  return gulp.src('src/assets/img/**/*.{jpg, png, gif}')
      .pipe(imagemin([
        imagemin.optipng({optimizationLevel: 3}),
        imagemin.jpegtran({progressive: true})
      ]))
      .pipe(gulp.dest('build/img'));
});
gulp.task('html', function () {
  return multipipe(
      gulp.src('src/*.html', {since: gulp.lastRun('html')}),
      debug({title: 'html'}),
      gulp.dest('build')
  ).on('error', notify.onError(function (err) {
    return {
      title: 'html',
      message: err.message
    };
  }));
});
gulp.task('fonts', function () {
  return gulp.src('src/assets/fonts/*.*')
      .pipe(gulp.dest('build/fonts'));
});


gulp.task('build', gulp.series(
    'clean',
    gulp.parallel('html', 'styles', 'min-js', 'images', 'fonts'),
    'images')
);


gulp.task('watch', function () {
  gulp.watch('src/*.html', gulp.series('html'));
  gulp.watch('src/sass/**/*.*', gulp.series('styles'));
  gulp.watch('src/assets/js/app.js', gulp.series('min-js'));
  gulp.watch('src/assets/img/**/*.{jpg, png, gif}', gulp.series('images'));
  gulp.watch('src/assets/fonts/*.*', gulp.series('fonts'));
});

gulp.task('deploy', function () {
  return gulp.src('./build/**/*')
      .pipe(ghPages());
});

gulp.task('serve', function () {
  browserSync.init({
    server: 'build'
  });

  browserSync.watch('build/**/*.*').on('change', browserSync.reload);
});

gulp.task('dev',
    gulp.series('build', gulp.parallel('watch', 'serve'))
);

package.json

{
  "name": "name",
  "version": "1.0.0",
  "description": "",
  "main": "gulpfile.js",
  "dependencies": {},
  "devDependencies": {
    "autoprefixer": "^7.1.2",
    "babel-core": "^6.26.0",
    "babel-preset-env": "^1.6.1",
    "browser-sync": "^2.18.13",
    "css-mqpacker": "^6.0.1",
    "debug": "^3.0.0",
    "del": "^3.0.0",
    "gulp": "github:gulpjs/gulp#4.0",
    "gulp-babel": "^7.0.0",
    "gulp-cssnano": "^2.1.2",
    "gulp-csso": "^3.0.0",
    "gulp-debug": "^3.1.0",
    "gulp-gh-pages": "^0.5.4",
    "gulp-if": "^2.0.2",
    "gulp-imagemin": "^3.3.0",
    "gulp-install": "^1.1.0",
    "gulp-newer": "^1.3.0",
    "gulp-notify": "^3.0.0",
    "gulp-path": "^4.0.0",
    "gulp-postcss": "^7.0.0",
    "gulp-rename": "^1.2.2",
    "gulp-rev": "^8.0.0",
    "gulp-rollup": "^2.15.0",
    "gulp-sass": "^3.1.0",
    "gulp-series": "^1.0.2",
    "gulp-sourcemaps": "^2.6.1",
    "gulp-svgmin": "^1.2.4",
    "gulp-svgstore": "^6.1.0",
    "gulp-uglify": "^3.0.0",
    "multipipe": "^1.0.2",
    "path": "^0.12.7",
    "stream-combiner2": "^1.1.1"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "",
    "url": ""
  },
  "author": "Batya Hack",
  "license": "ISC",
  "bugs": {
    "url": ""
  },
  "homepage": "