Disallow null or undefined values.

[DylanRJohnston]

I think supplying undefined or null values to the constructor should throw a type error. If a field can be null then it should be modelled with a maybe type.

This allows the constructors to play more nicely with other parsing functions.

[DylanRJohnston]

For example

const encase = f => x => {
  try {
    return Right(f(x))
  } catch(error) {
    return Left(error)
  }
}

// objectToMessage :: Object -> Either Error OutGoingMessage
const objectToMessage = encase({id, data, requestType, requestUUID} => 
  OutgoingMessage(id, data, requestType, requestUUID)
)

So we handle object being null and any of the fields missing.

[safareli]

I think supplying undefined or null values to the constructor should throw a type error. If a field can be null then it should be modelled with a maybe type.

We shouldn't disallow null values. if you don't want to use null it's your choice you can use whatever you want. if you want type checking for sum types check this

Also with this restriction you are trying to bring in, we can't define valid Maybe type using daggy as Maybe.Just(null) will throw.

So I don't think this is the change we should apply.

[DylanRJohnston]

That's a good point. Hadn't considered constructors without any fields.