What design patterns do you use in your automation framework?

The following design patterns are often used in test automation:

• Page Object Pattern — for encapsulating the logic of interacting with UI elements into separate classes, which facilitates maintenance and reuse of code.
• Singleton — for creating a single instance of a driver or configuration manager.
• Factory Pattern — for creating test data objects or framework components, allowing easy changes of implementations.
• Strategy Pattern — for selecting different algorithms or methods of executing tests (e.g., different login methods).
• Observer Pattern — for implementing events and logging in tests.

Example of using Page Object in Python with Selenium:

class LoginPage:
    def __init__(self, driver):
        self.driver = driver
        self.username_input = driver.find_element_by_id('username')
        self.password_input = driver.find_element_by_id('password')
        self.login_button = driver.find_element_by_id('login')

    def login(self, username, password):
        self.username_input.send_keys(username)
        self.password_input.send_keys(password)
        self.login_button.click()