Protobuf.js: Why doesnt fromObject() fail for invalid enum values?

[kostyay]

protobuf.js version: 6.7.3

If I use MyMessage.fromObject({'myEnum': 'invalid'}) I would expect the function to fail in case invalid is not one of the possible options for the enum. Current behavior just ignores the field and doesn't add anything into the resulting MyMessage instance.

enum MyEnum {
  VAL1 = 0;
  VAL2 = 1;
}

message MyMessage {
  string id = 1;
  MyEnum myEnum = 2;
}

MyMessage.fromObject({'myEnum': 'invalid', id: "22"}) // returns {id: "22"} which is valid

[dcodeIO]

fromObjectisn't a validator but does just one thing: Create a message from an object through naive conversions. It's not in the resulting message because MyEnum["invalid"] evaluates to undefined.

You can read more about this here: https://github.com/dcodeIO/protobuf.js#toolset

[kostyay]

It would be nice then to have the verify function to support string values for enums as well then, or perhaps some other function that will have that kind of functionality. Currently I have to perform that validation by myself and I think it could be a useful addition to the library.

[dcodeIO]

Hmm, well, when I think of it more, fromObject could also just throw in this case because it already throws for other "bogus" values. You're probably doing something like the following atm, correct?

function checkEnum(ReflectedEnum, val) {
  if (ReflectedEnum[val] == null)
    throw Error("not a valid enum value");
  return val;
}

MyMessage.fromObject({'myEnum': checkEnum(MyEnum, val), id: "22"})