I Hate Javascript Error Report

Pardon my english.

I am not expert in javascript but why I getting error on this line:

  this.props
>   .save()
    .catch(err => /* code to tell user it failed to save */)

With error message: this.props.save(…) is undefined. When the exact error is save() return undefined instead of promise.

It will be clear if error message is: call .catch on undefined. Then life will be easier.