Move spec JavaScript files to TypeScript

[cnishina]

Placeholder.

[pittgoose]

I'd love to contribute to this. Is this a matter of a straight conversion of test files from JS to TS? I could totally take this project.

[cnishina]

Woo hoo! Thanks for volunteering!

This is going to not make this milestone since it was more of a wishlist type item. I am thinking we could be split between several of us: you, me, and @CrispusDH. I'll do something similar to #5017 where we have a list of test cases that need to be migrated.

I also want to have a PR that is a sample commit.... so let me do this first. I'm out at the end of the week for the holidays but maybe we do this in 2019?

[IgorSasovets]

@cnishina , I'd also help to deal with it if needed.

[pittgoose]

@cnishina Great! I'll keep an eye out for word from you.

[simonua]

If there's a first-come, first-serve list of items to choose from, I might be able to contribute time and commits as well.