title: Using gulp.watch with browserified karma/jasmine unit tests fails on error
body: <p>I'm running into <a href="https://github.com/gulpjs/gulp/issues/627" rel="nofollow">this error with gulp.watch</a>. Essentially, when a test unit fails with an error, then the watch command hangs--i.e. runs exactly once and then watch does not trigger events again.</p>
  
  <p>The prescribed workaround is to use <a href="https://www.npmjs.org/package/gulp-plumber" rel="nofollow">gulp-plumber</a> to prevent exit on errors. However, this only works with streams. If I'm running karma tests together with browserify, my configuration looks similar to this (and I can't determine how to hook streams into this bad boy to enable plumber):</p>
  
  <pre><code>gulp.task('watch', function() {
    gulp.watch('src/**/*.js', ['test']);
    gulp.watch('test/**/*.spec.js', ['test']);
  });
  
  gulp.task('test', function () {
    return karma.server.start({
      files: [
        'test/**/*.spec.js'
      ],
      frameworks: ['browserify', 'jasmine'],
      preprocessors: {
        'test/**/*.spec.js': ['coverage', 'browserify']
      },
      browsers: ['PhantomJS'],
      reporters: ['coverage', 'spec', 'failed'],
      browserify: {
        debug: true,
        transform: ['browserify-istanbul']
      },
      singleRun: true
    });
  });
  </code></pre>
  
  <p>Does anyone have a workaround for running test units with watch or recommendations on how I could get this to work with gulp-plumber?</p>