title: Error handling with gulp-notify and gulp-plumber
body: <p>I want to display a notification when:<br/>
  1. An error occurs<br />
  2. When the script was successfully executed <br /></p>
  
  <p>All notifications are actually working but the success notification is always displayed, even when there is an error.</p>
  
  <p>How can I make sure the success notification is only displayed when no errors have occurred?</p>
  
  <p>This is my current task:</p>
  
  <pre><code>var gulp = require('gulp');
  var sass = require('gulp-ruby-sass');
  var rename = require('gulp-rename');
  var notify = require('gulp-notify');
  var plumber = require('gulp-plumber');
  var minifycss = require('gulp-minify-css');
  var autoprefixer = require('gulp-autoprefixer');
  
  gulp.task('sass', function(){
     return gulp.src('assets/scss/global.scss')
         .pipe(plumber({errorHandler: notify.onError("Error: &lt;%= error.message %&gt;")}))
         .pipe(sass({ style: 'expanded' }))
         .pipe(autoprefixer())
         .pipe(gulp.dest('assets/css/'))
         .pipe(rename({suffix: '.min'}))
         .pipe(minifycss())
         .pipe(gulp.dest('assets/css/'))
         .pipe(notify({
             title: 'Gulp',
             subtitle: 'success',
             message: 'Sass task',
             sound: "Pop"
         }));
  });
  
  gulp.task('watch', function(){
     gulp.watch('assets/scss/**/*.scss', ['sass']);
  });
  
  gulp.task('default', ['sass', 'watch']);
  </code></pre>