In the previous article, we used gulp to validate our JavaScript. The error message would appear in the console. While this is awesome, there is a chance we could miss it.

Let’s use notifications to display a pop up window when we have a JavaScript error.

There is a gulp plugin to send notifications.

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$ npm install gulp-notify --save-dev

For more information on gulp-notify check out https://www.npmjs.org/package/gulp-notify

Remember that gulp uses node’s streaming. It shouldn’t be a surprise that when gulp-jsvalidate finds an error, it emits an error event.

All we need to do is handle the event and use gulp-notify to send a notification with the error message.

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...
var notify = require('gulp-notify');
...

...
gulp.task('javascript', function () {
  console.log("Validate JavaScript");
  return gulp.src("contents/javascripts/**.js")
    .pipe(jsValidate())
    .on("error", notify.onError(function(error) {
      return error.message;
    }));
});
...

Since our JavaScript is now valid, we need to make it invalid so we can see the error message.

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function OMG() {
  var x * 2;
  return x + 10;
}

Now when we run gulp javascript we will get a notification window that an error was found.

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$ gulp javascript

Using gulpfile ~/YOUR_DIRECTORY/gulpFile.js
Starting 'javascript'...
Validate JavaScript
gulp-notify: [Error running Gulp] Line 3: Unexpected token *
'javascript' errored after 41 ms Line 3: Unexpected token *