gulp : browserify then concat files
<p>I need to browserify a file, and then to concat the bundle with another file. I tried the gulp code below but it's not working properly.<br>
When I make changes in mymodule.js and run gulp, those changes appear in the bundle file but not in the concatenated file, unless I run gulp a second time.<br>
It's like if the concat step is not waiting for the bundle step to finish and take the previously browserified bundle.
As I'm a beginner with gulp, I'm sure there is something wrong with my gulp logic...</p>

<p>My gulpfile is :</p>

<pre><code>var gulp = require('gulp');
var browserify = require('browserify');
var source = require('vinyl-source-stream');
var concat = require('gulp-concat');

gulp.task('default', function() {
  var b = browserify('src/mymodule.js')
  .bundle()
  .pipe(source('mymodule-bundle.js'))
  .pipe(gulp.dest('src'));

  gulp.src([
        'bower_components/porthole/src/porthole.min.js',
        'src/mymodule-bundle.js'
    ])
    .pipe(concat('app.js'))
    .pipe(gulp.dest('dist'));
});
</code></pre>

<p>Thanks</p>