Add Sync helpers for scala.Predef assertions

[DavidGregory084]

I'm opening this for discussion after the idea came up while chatting with @armanbilge on typelevel/bobcats#106.

I'm not 100% sure whether this is a useful addition - I have some sympathy for the idea that assert and require express critical preconditions and that it's okay if the runtime explodes if those preconditions are not satisfied.

I chose Sync because I think it's the first place in the hierarchy that knows that the error channel is Throwable.

[armanbilge]

I chose Sync because I think it's the first place in the hierarchy that knows that the error channel is Throwable.

Thanks for the PR! I guess I wasn't very clear in typelevel/bobcats#106 (comment) but actually I think these belong in Cats alongside ApplicativeThrow#catchNonFatal and friends (note that ApplicativeThrow is a type alias for ApplicativeError[*, Throwable]).

Sync is a very strong constraint and may not always be where this functionality is needed.

[DavidGregory084]

Hmm OK, so we would add these as extension methods on ApplicativeThrow?

[armanbilge]

So Cats add the methods to ApplicativeError but requires evidence that Throwable <:< E
https://github.com/typelevel/cats/blob/9839b7498e81b1405d3e41c88d24ce73e316e69d/core/src/main/scala/cats/ApplicativeError.scala#L247

[rossabaker]

Because I had to look it up, AssertionError is NonFatal. I agree that ApplicativeError would work well.

[DavidGregory084]

Superseded by typelevel/cats#4249