}

    @ParameterizedTest
    @DisplayName("Test valid usernames")
    @ValueSource(strings = { "user", "user123", "user.name", "user-name", "user_name", "******@****.***" })
    void testValidUsernames(String username) {
        assertDoesNotThrow(() -> InputValidator.validateUsername(username));
    }

    @ParameterizedTest
    @DisplayName("Test invalid usernames")