Tests aren’t enough: Case study after adding type hints to urllib3(sethmlarson.dev)

    var instance = new SomeClass();

  compose(f, f1, f2, f3)

  f . f3 . f2 . f1

  f1 |- f2 |- f3 |- f

  let (|-) f g = fun x -> g (f x)
  (|-): (’a -> ’b) -> (’b -> ’c) -> (’a -> ’c)

  from typing import Callable, Any

  def compose(start: Callable[[Any], Any], *args: Callable[[Any], Any] -> Callable[[Any], Any]:
    def helper(x: Any) -> Any:
      for func in reversed(args):
        x = func(x)
      return start(x)
    return helper

  fn compose<X, T>(start: Box<Fn(T) -> X>, args: Vec<Box<Fn(T) -> T>>) -> Fn(T) -> X {
    move |x: X| {
      let mut x = x;
      for func in args.iter(). reversed() {
        x = func(x);
      }
      start(x)
    }
  }

    function find_user(person: string)

    function find_user(person: Object)

    find_user(person: { name: "dave" })

  def __init__(self, host, port=1234, scheme='https'):

      if not isinstance(ip, str):
         raise TypeError('invalid host')

      self.url = f"{scheme}://{host}:{port}"

  def original__init__(self, ip_address):
      self.ip_address = ipaddr.IPAddress(ip_address)
  def new__init__(self, ip_address):
      ipaddr.IPAddress(ip_address) # just to validate
      self.ip_address = ip_address