How do you writing bindings today?

I don’t recommend the options, because when there’s a function overload on js side you want to bind to multiple functions like:

module SomeLib = {
  @module("xx") @scope("default")
  external execString: string => int = "exec"

  @module("xx") @scope("default")
  external execInt: int => int = "exec"
}

SomeLib.execString()