# bad
user = {"first_name": "John", "last_name": "Doe"}
full_name = f"{user['first_name']} {user['last_name']}"


# better

class User:
    def __init__(self, first_name, last_name):
        self.first_name = first_name
        self.last_name = last_name

    def full_name(self):
        return f"{self.first_name} {self.last_name}"


user = User(first_name='John', last_name='Doe')
print(user.full_name())


# Good test
def test_full_name_consists_of_first_name_and_last_name():
    # arrange
    first_name = 'John'
    last_name = 'Doe'
    user = User(first_name=first_name, last_name=last_name)

    # act
    full_name = user.full_name()

    # assert
    assert full_name == "John Doe"


test_full_name_consists_of_first_name_and_last_name()


class InMemoryUserReposity:
    def __init__(self):
        self._users = []

    def add(self, user):
        self._users.append(user)

    def get_by_first_name(self, first_name):
        return next(
            user for user in self._users if user.first_name == first_name
        )


first_name = 'John'
last_name = 'Doe'
user = User(first_name=first_name, last_name=last_name)
repository = InMemoryUserReposity()
repository.add(user)


# BAD
def test_add():
    first_name = 'John'
    last_name = 'Doe'
    user = User(first_name=first_name, last_name=last_name)
    repository = InMemoryUserReposity()
    repository.add(user)

    assert user in repository._users


def test_get_by_first_name():
    first_name = 'John'
    last_name = 'Doe'
    user = User(first_name=first_name, last_name=last_name)
    repository = InMemoryUserReposity()
    repository._users = [user]

    user_from_repo = repository.get_by_first_name(first_name)

    assert user_from_repo == user


# GOOD TEST:


def test_added_user_can_be_retrieved_by_first_name():
    first_name = 'John'
    last_name = 'Doe'
    user = User(first_name=first_name, last_name=last_name)
    repository = InMemoryUserReposity()
    repository.add(user)

    assert user == repository.get_by_first_name(user.first_name)


import pytest


class Player:
    def __init__(self, username):
        if len(username) < 1:
            raise Exception("Username bust not be empty.")
        self._username = username

    @property
    def username(self):
        return self._username


def test_user_with_valid_username():
    username = "John"
    assert Player(username=username).username == username


def test_user_error():
    username = ""
    with pytest.raises(Exception):
        Player(username)


test_user_with_valid_username()
test_user_error()