Does withConverter need to have fromFirestore and toFirestore?

[joshpetit]

On the client side I'm only ever reading documents, so I was wondering if it was really necessary to make the toFirestore field required on withConverter for documents? Shouldn't it only be required when you're writing data? I'd supposed the same for the other way around, you shouldn't really need to define a fromFirestore if you're only writing data.

[rrousselGit]

If you don't want to implement toFirestore, you're free to throw an exception

toFirestore: (value, options) => throw UnsupportedError(),

[joshpetit]

Amazing thanks, is this in the docs already? If not would be a great addition!