Remove null from signature of formatDate

[ntrinquier]

Fixes #2612

Changes proposed in this pull request:

As per #2612 - Remove null from the signature of the formatDate function.

Reviewers should focus on:

This is a non-backward compatible API change.

Screenshot

N/A

[giladgray]

I am not convinced by the issue. Gonna write a test real quick.

[giladgray]

ok seems legit. the code does in fact capture null values so formatDate never receives them.

i feel like there's a use case for formatting the null value but since it's not implemented that way, let's merge this to correct the typings.

also this is definitely backwards-compatible as a (date: Date | null) => string function can be passed to a (date: Date) => string prop.

[giladgray]

@ntrinquier ok wait i just realized you targeted the 4.x branch which is not a thing. please try again on develop.

[giladgray]

sorry, ignore that comment. i can just merge 4.x into develop.

[giladgray]

you definitely should have called that out in the description.

[giladgray]

also for the record, if this were breaking i would have rejected it as there's no way i'm about to start on 4.0.0 😂

thanks for the contribution @ntrinquier!!

[ntrinquier]

@giladgray As you said there's likely a use case for formatting the null value, but right now it's confusing since it is never going to be called anyway :)
Thanks for taking care of all the branching!