title: How to add src files in the middle of a pipe
body: <p>I want to process some files with 'coffee', add some js files, concat and minify.</p>
  
  <p>This does not work, coffee fails on the regular js files:</p>
  
  <pre><code>gulp.task 'build-js', -&gt;
    gulp.src([
        "bower_components/mbdev-core/dist/js/db.js"
        "bower_components/mbdev-core/dist/js/utils.js"
        "src/js/config/app.coffee"
        "src/js/config/app-db.coffee"              
        "src/js/accounts/accounts.coffee"
        "src/js/budget_items/budget_items.coffee"
        "src/js/line_items/line_items.coffee"
        "src/js/misc/misc.coffee"
        "src/js/reports/report_generators.coffee"
        "src/js/reports/reports.coffee"
     ])
    .pipe(coffee()).on('error', gutil.log)
    .pipe(concat('app.js'))
    .pipe(gulp.dest('public/js'))
  </code></pre>
  
  <p>Is there a way to add files after the coffee part?</p>