Gulp 4 with bootstrap 4

.gitignore

*.user
.DS_Store

**/node_modules/*
**/obj/*
**/bin/*
**/.vs/*
**/fontawesome/*

src/Gulp.Bootstrap/wwwroot/lib
src/Gulp.Bootstrap/wwwroot/scripts
src/Gulp.Bootstrap/wwwroot/styles

gulpfile.js

/// <binding ProjectOpened='default' />
'use strict';

const gulp          = require("gulp");
const autoprefixer  = require('gulp-autoprefixer');
const minifycss     = require('gulp-clean-css');
const rename        = require('gulp-rename');
const sass          = require('gulp-sass');
const sourcemaps    = require('gulp-sourcemaps');

function scss() {
    return gulp
        .src("Styles/**/*.scss")
        .pipe(sass({ 
            includePaths: [
                'node_modules'
            ],
            outputStyle: "expanded" 
        }))
        .pipe(sourcemaps.init())
        .pipe(sass().on('error', sass.logError))
        .pipe(autoprefixer())
        .pipe(gulp.dest("wwwroot/styles"))
        .pipe(minifycss())
        .pipe(rename({ suffix: '.min' }))
        .pipe(sourcemaps.write('.'))
        .pipe(gulp.dest("wwwroot/styles"));
}

function css() {
    return gulp
        .src([
            "Styles/**/*.css"
        ])
        .pipe(gulp.dest("wwwroot/scripts"));
}

function icons() {
    return gulp
        .src([
            "node_modules/@fortawesome/fontawesome-free/svgs/solid/*.svg"
        ])
        .pipe(gulp.dest("wwwroot/images/fontawesome/svgs/solid"));
}

function js() {
    return gulp.src([
            'node_modules/bootstrap/dist/js/*'
        ])
        .pipe(gulp.dest("wwwroot/scripts"));
}

function watch() {
    gulp.watch("Styles/**/*.scss", scss);
}

const build = gulp.parallel(scss, css, js, icons);

exports.js = js;
exports.css = css;
exports.sass = scss;
exports.icons = icons;
exports.watch = watch;
exports.default = build;

package.json

{
  "name": "gulp.bootstrap",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "private": true,
  "devDependencies": {
    "@fortawesome/fontawesome-free": "^5.12.0",
    "bootstrap": "^4.4.1",
    "gulp": "^4.0.2",
    "gulp-autoprefixer": "^7.0.1",
    "gulp-clean-css": "^4.2.0",
    "gulp-rename": "^2.0.0",
    "gulp-sass": "^4.0.2",
    "gulp-sourcemaps": "^2.6.5"
  }
}