How to fix error with gulp.js?

Question

gulp.js

I made a starting gulp build for projects, there was a problem, " 'js' errored after 5.36 ms ",
while everything works as before, but it didn’t work out, I need help


, that’s all that is written in 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')
        .pipe(sass({outputStyle: 'compressed'}))
        .pipe(rename({suffix: '.min'}))
        .pipe(autoprefixer({
          overrideBrowserslist: ['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'
  ])
    .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',
  ])
    .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'))