Pass invalid values to the onDateChange prop

[marcgarygray]

I believe it would be helpful to a lot of developers to be able to know if an invalid date has been typed by the user into the <input type="text"> node. In my opinion, the most logical place to provide that information would be in the onDateChange handler. I could see an argument for a simple boolean that's false if the input is not a valid moment.Moment or passing the invalid input as a string.
I know that an invalid input just passes null as the date to the handler, but that being the case, there's no way to differentiate between the user simply clearing the data (a valid interaction) versus entering text that can't be parsed into a valid date (an invalid interaction).

If you allow pull requests from the masses, I would be more than happy to make the change and submit a PR.

[marcgarygray]

Note

This is for the <SingleDatePicker> specifically. It's the only component from this library that I've utilized thus far. I'm not sure if this is the same or different across all of the components exported by the library.

[ljharb]

If there's a nonbreaking way to also pass the original input string, I'd be open to that.

I think this might be a duplicate of #1023?

[marcgarygray]

@ljharb
Are you open to outside contributions? I'm happy to make the change.
If so, any guidelines (PR must come with a test, etc., etc.) are appreciated. :)

[ljharb]

Yes, absolutely! Tests are a requirement; a storybook story is nice but not required.

It'd be ideal to make this change on every component in the library, so that everything can follow similar patterns.

[marcgarygray]

@ljharb working on this tonight.
Looks like your workflow is to create a branch named something like username/issue#/description and make a PR to merge that branch to master, yeah?

[ljharb]

The workflow in general terms for making a PR to any open source project is to fork the repo, make a branch on the fork with your changes, and then make a PR to merge that to the source's default branch (usually master).

[marcgarygray]

@ljharb thanks. Submitted. 👍