code: function middleware(file, options) {
    var matcher = new RegExp("\\.(?:"+ middleware.extensions.join("|")+")$")
    if (!matcher.test(file)) return through();
  
    var input = '';
    var write = function (buffer) {
      input += buffer;
    }
  
    var end = function () {
      this.queue(createModule(input, options));
      this.queue(null);
    }
  
    return through(write, end);
  
  }
docs: create middleware for handling shader files