Cancel/abort upload process (Feature request)

When the lib receives files and fields, it starts to receive (upload) files in any case. For example, I check form fields for emptiness, and reject the request. But it still accepts the files and stores them, and I can’t prevent it.

form.on("field", function (name, value) {
  // Reject if a form field value is empty
  if (_.isEmpty(value)) {
    return res.sendStatus(400);
    // Want to cancel processing of the form here, but the lib continues
  }
});
form.on("file", function (name, value) {
  // And accepts the file, stores it, and reaches here
});

So in this example, if the received form consists of an empty field, and a file, its not possible to stop the file from being accepted (correct me if I’ve mistaken).

[GrosSacASac]

I am on it

[tunnckoCore]

Okay, I think the easiest and cleanest approach for now is the “file methods noop-ing” (file.open = () => {} & etc), so it woundn’t even create a writeStream in first place.

Other future approach could Validators API, like options.validators = [] and then calling them from the part.on('data') passed with the this, part, file and the buffer. ry catch inside that loop, and if catch error call this._error. Plus some if check before the file.open() couple lines above.