Add onEnd handler or then promise

[a-x-]

I use estraverse look for a specific node and I return the promise.
I cannot throw reject on traverse complete without workarounds.

function retrieveBemEntity (fileContent, offset) {
  return new Promise(function (res, err) {
    var ast = parse.parseExpressionAt(fileContent.substr(offset));
    traverse.traverse(ast, {enter: function (node) {
      var bemEntity = _onNode(node);
      if (bemEntity) res(bemEntity), this.break();
    }});
    setTimeout(()=>err('not found'), 100); // todo add traverse.traverse on end handler
  });
}

[a-x-]

ping