Ruby TypeProf Playground

def hello_message(user)

  "The name is " + user.name

end

​

def type_error_demo(user)

  "The age is " + user.age

end

​

​

user = User.new(name: "John", age: 20)

​

hello_message(user)

type_error_demo(user)

class User

  def initialize: (name: String, age: Integer) -> void

​

  attr_reader name: String

  attr_reader age: Integer

end