gulpfile.js

let gulp = require("gulp"),
  sass = require("gulp-sass"),
  rename = require("gulp-rename"),
  browserSync = require("browser-sync"),
  autoprefixer = require("gulp-autoprefixer"),
  concat = require("gulp-concat"),
  uglify = require("gulp-uglify"),
  cssmin = require("gulp-cssmin");

gulp.task("sass", function() {
  return gulp
    .src("app/scss/**/*.scss", "app/scss/style.scss")
    .pipe(sass({ outputStyle: "compressed" }))
    .pipe(rename({ suffix: ".min" }))
    .pipe(
      autoprefixer({
        overrideBrowsers: ["last 8 versions"]
      })
    )
    .pipe(gulp.dest("app/css"))
    .pipe(browserSync.reload({ stream: true }));
});

gulp.task("style", function() {
  return gulp
    .src([
      "node_modules/normalize.css/normalize.css",
      "node_modules/slick-carousel/slick/slick.css",
      "node_modules/magnific-popup/dist/magnific-popup.css",
      "node_modules/rateyo/src/jquery.rateyo.css",
      "node_modules/ion-rangeslider/css/ion.rangeSlider.css",
      "node_modules/@fancyapps/fancybox/dist/jquery.fancybox.css",
      "node_modules/jquery-form-styler/dist/jquery.formstyler.css",
      "node_modules/jquery-form-styler/dist/jquery.formstyler.theme.css"
    ])
    .pipe(concat("libs.min.css"))
    .pipe(cssmin())
    .pipe(gulp.dest("app/css"));
});
gulp.task("script", function() {
  return gulp
    .src([
      "node_modules/slick-carousel/slick/slick.js",
      "node_modules/magnific-popup/dist/jquery.magnific-popup.js",
      "node_modules/mixitup/dist/mixitup.js",
      "node_modules/rateyo/src/jquery.rateyo.js",
      "node_modules/ion-rangeslider/js/ion.rangeSlider.js",
      "node_modules/@fancyapps/fancybox/dist/jquery.fancybox.js",
      "node_modules/jquery-form-styler/dist/jquery.formstyler.js"

    ])
    .pipe(concat("libs.min.js"))
    .pipe(uglify())
    .pipe(gulp.dest("app/js"));
});

gulp.task("html", function() {
  return gulp.src("app/*.html").pipe(browserSync.reload({ stream: true }));
});

gulp.task("js", function() {
  return gulp.src("app/js/*.js").pipe(browserSync.reload({ stream: true }));
});

gulp.task("browser-sync", function() {
  browserSync.init({
    server: {
      baseDir: "app/"
    }
  });
});

gulp.task("watch", function() {
  gulp.watch("app/scss/**/*.scss", gulp.parallel("sass"));
  gulp.watch("app/*.html", gulp.parallel("html"));
  gulp.watch("app/js/*.js", gulp.parallel("js"));
});
gulp.task(
  "default",
  gulp.parallel("style", "script", "sass", "watch", "browser-sync")
);