callback boilerplate.js

_doGetResourceTree: function(params, done) {
  this._debuggerClient.evaluateGlobal('process.argv[1]', function(err, argv1) {
    if (err) return done(err);
    this._scriptStorage.findApplicationRoot(argv1, function(root) {
      this._scriptStorage.findAllScripts(root, function(err, files) {
        if (err) return done(err);
        return done(null, this._createResourceTreeResponse(files));
      }.bind(this));
    }.bind(this));
  }.bind(this));
}

improved.js

_doGetResourceTree: function(params, done) {
  async.waterfall(
    [
      this._debuggerClient.evaluateGlobal.bind(this._debuggerClient, 'process.argv[1]'),
      this._scriptStorage.findApplicationRoot.bind(this._scriptStorage),
      this._scriptStorage.findAllScripts.bind(this._scriptStorage)
    ],
    function(err, files) {
      if (err) return done(err);
      return done(null, this._createResourceTreeResponse(files));
    }.bind(this)
  );
}