Fix gulpfile

gulpfile.js

@@ -5,6 +5,8 @@ const sass = require("gulp-sass");
 const babel = require("gulp-babel");
 const uglify = require("gulp-uglify");
 const del = require("del");
+const postcss = require("gulp-postcss");
+const tailwindcss = require("tailwindcss");
 
 // Default settings for gulpfile
 var project = {
@@ -26,9 +28,11 @@ gulp.task("watch", done => {
     gulp.series("scripts")
   );
 
-  // Using gulp-watch as standard gulp
-  // doesn't track files the same way.
-  // See: https://stackoverflow.com/questions/42890414/how-to-setup-gulp-watch-with-gulp-connect-livereload
+  /**
+    Using gulp-watch as standard gulp
+    doesn't track files the same way.
+    See: https://stackoverflow.com/questions/42890414/how-to-setup-gulp-watch-with-gulp-connect-livereload
+  */
   watch(project.buildDest).pipe(connect.reload());
 
   done();
@@ -53,6 +57,7 @@ gulp.task("stylesheets", done => {
   gulp
     .src(project.buildSrc + "/assets/stylesheets/app.scss")
     .pipe(sass().on("error", sass.logError))
+    .pipe(postcss([tailwindcss("./tailwind.js"), require("autoprefixer")]))
     .pipe(gulp.dest(project.buildSrc + "/_includes/stylesheets"));
   done();
 });
@@ -67,13 +72,12 @@ gulp.task("server", done => {
 });
 
 // Clean build dir
-gulp.task("clean", done => {
-  del([project.buildDest + "/**/*"]);
-  done();
+gulp.task("clean", function () {
+  return del([project.buildDest + "/**/*"]);
 });
 
 // Build task
-gulp.task("build", gulp.series("clean", "stylesheets", "scripts"));
+gulp.task("build", gulp.parallel("clean", "stylesheets", "scripts"));
 
 // Development task
 gulp.task("dev", gulp.parallel("watch", "stylesheets", "scripts", "server"));