Tdd examples from http://scholarcoder.com/1392/ttd-intro

UserServiceStep1FindByUserName.java

class UserService {
  
    List<User> users = new ArrayList<>();
    {
        User user = new User();
        user.username = "adrianvdh";
        user.password = "hello123";
        users.add(user);
    }
  
    public User authenticate(String username, String password) {
        User foundUser = null;
        for (User userInCollection : users) {
            if (userInCollection.username.equals(username)) {
                foundUser = userInCollection;
                break;
            }
        }
        
        return foundUser;
    }
}