import unittest
import importlib

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

class TestRegisterUser(unittest.TestCase):
    def setUp(self):
        """Reset users_db before each test"""
        import user_code
        user_code.users_db.clear()

    def test_successful_registration(self):
        """Checks that a user is successfully registered with valid data"""
        import user_code
        try:
            result = user_code.register_user(username="Alice", email="alice@example.com", age=18)
            expected_output = "User Alice registered successfully!"
            condition = result == expected_output
            failure_message = f"For input `('Alice', 'alice@example.com', 18)`, expected `{expected_output}`, but got `{result}`."
        
        except AttributeError:
            condition = False
            failure_message = "The function `register_user` is not defined."
        
        _dynamic_test(self, condition, "The `register_user` function registers a user correctly.", failure_message)
    
    def test_user_count_after_registration(self):
        """Checks that the number of users in the database is correct after a successful registration"""
        import user_code
        try:
            user_code.register_user(username="Alice", email="alice@example.com", age=18)
            condition = len(user_code.users_db) == 1
            failure_message = f"For input `('Alice', 'alice@example.com', 18)`, expected 1 user in the database, but found {len(user_code.users_db)}."
        
        except AttributeError:
            condition = False
            failure_message = "The function `register_user` is not defined."
        
        _dynamic_test(self, condition, "The number of registered users is correct.", failure_message)
    
    def test_user_data_after_registration(self):
        """Checks that the user data is correctly added to the database after a successful registration"""
        import user_code
        try:
            user_code.register_user(username="Alice", email="alice@example.com", age=18)
            registered_user = user_code.users_db[0]
            condition = (registered_user["username"] == "Alice" and
                         registered_user["email"] == "alice@example.com" and
                         registered_user["age"] == 18)
            failure_message = f"For input `('Alice', 'alice@example.com', 18)`, expected user data `{{'username': 'Alice', 'email': 'alice@example.com', 'age': 18}}` in `users_db`, but got {registered_user}."
        
        except AttributeError:
            condition = False
            failure_message = "The function `register_user` is not defined."
        except Exception:
            condition = False
            failure_message = "For input `('Alice', 'alice@example.com', 18)`, expected user data `{{'username': 'Alice', 'email': 'alice@example.com', 'age': 18}}` in `users_db`, but this element won't be found there."
        
        _dynamic_test(self, condition, "The user data is correctly stored in the database.", failure_message)
    
    def test_underage_registration(self):
        """Checks that users under 18 cannot register"""
        import user_code
        try:
            result = user_code.register_user(username="Bob", email="bob@example.com", age=16)
            expected_output = "Registration failed: age must be 18 or older."
            condition = result == expected_output and len(user_code.users_db) == 0
            failure_message = f"For input `('Bob', 'bob@example.com', 16)`, expected `{expected_output}`, but got `{result}`."
        
        except AttributeError:
            condition = False
            failure_message = "The function `register_user` is not defined."
        
        _dynamic_test(self, condition, "The `register_user` function correctly blocks underage users.", failure_message)
    
    def test_multiple_registrations(self):
        """Checks that multiple users can be registered"""
        import user_code
        try:
            user_code.register_user(username="Alice", email="alice@example.com", age=18)
            user_code.register_user(username="Charlie", email="charlie@example.com", age=30)
            condition = len(user_code.users_db) == 2
            failure_message = f"For input registrations `('Alice', 'alice@example.com', 18)` and `('Charlie', 'charlie@example.com', 30)`, expected 2 users, but found {len(user_code.users_db)}."
        
        except AttributeError:
            condition = False
            failure_message = "The function `register_user` is not defined."
        
        _dynamic_test(self, condition, "The `register_user` function allows multiple users to register.", failure_message)

    def test_users_db_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'users_db'),
            "The `users_db` variable is declared.",
            "Expected `users_db` to be declared."
        )

if __name__ == '__main__':
    unittest.main()

test_main.py

Få en solid forståelse af, hvordan funktioner former Python-programmering. Opnå færdigheder i at definere og kalde funktioner, arbejde med argumenter, håndtere returværdier samt skabe fleksibel og effektiv kode ved hjælp af rekursion og lambda-udtryk.

Undersøg, hvad funktioner er, og hvorfor de er essentielle i Python. Lær at oprette funktioner, definere argumenter, håndtere returværdier og anvende indbyggede funktioner effektivt.

Udfordring: Positionelle Argumenter

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