SebastianVerified account

Unclear why the original function signature can't be carried over. Feels like a technical limitation rather than a type system one. Flow has the same issue (although it handles it and related even worse).

Back compat. Bind used to be weakly typed for technical limitation reasons, now it works as expected under the --strict flag (which opts you in to new behavior) or specifically --strictBindCallApply

Will --strict ever be default?

We haven't ruled it out, but I think it's easy to under-estimate how disruptive that might be. Do checkJs users want --strict? How many people will know to turn --strict off when migrating?

if they don’t, they can disable it. You can make the error messages describe how to shut it off, so everyone will know how.

We can't, though. The strict flags generally change *how the type system works* and you can't precisely or accurately predict whether any given error would have occurred with strict off