Refactoring to utilize new recursive conditional feature

[dgreene1]

Please feel free to close this issue @piotrwitek as it’s not really a request. It’s just me wanting to share a cool new feature that Typescript is releasing soon that might help with this library:
microsoft/TypeScript#40002

But since this is not a concrete request, I will self close the issue. Just didn’t know how else to reach you to make you aware of this cool new feature that might help this library.

[piotrwitek]

Hey @dgreene1,

Thanks for sharing your thoughts, actually it's a pretty good suggestion and I would like it to stay open in the backlog.

PR Welcomed!