I’m trying to create a generic bind function for TypeScript that will apply a function with any number of parameters to a specific this value.

Without types, the idea is simple:

function bind(self, fn) {
    return (...args) => fn.apply(self, ...args);
}

But I can’t seem to string together the right types to satisfy the type system.

function bind<TThis, TFunction extends Function>(self: TThis, fn: TFunction):
  (this: TThis, ...args: Parameters<TFunction>) => ReturnType<TFunction>  {
    return (...args: any[]) => fn.apply(self, ...args);
}