Test Automation - Efficient Element Selection with Playwright Python using Test IDs

Introduction

In web application testing, efficiently selecting elements is crucial for consistent and reliable test execution. Common challenges include ensuring selectors are properly set up, and element selection is intuitive and maintainable. Playwright, combined with Pytest, offers powerful solutions to address this need efficiently.

The solution presented in this article is exemplified in my Playwright Python example project, developed in collaboration with Elias Shourosh. It demonstrates how to use a Pytest fixture to configure browser launch arguments, set-up selectors, and leverage Playwright’s improved element selection methods, ensuring a consistent and efficient testing environment across all tests in a session.

Implementing the Solution

The solution code can be found here.

@pytest.fixture(scope="session")
def browser_type_launch_args(browser_type_launch_args: Dict, playwright: Playwright):
    """Fixture to set browser launch arguments.

    This fixture updates the browser launch arguments to start the browser maximized
    and sets the test ID attribute for selectors.

    Args:
        browser_type_launch_args (Dict): Original browser type launch arguments.
        playwright (Playwright): The Playwright instance.

    Returns:
        Dict: Updated browser type launch arguments with maximized window setting.

    Note:
        This fixture has a session scope, meaning it will be executed once per test session.

    See Also:
        https://playwright.dev/python/docs/api/class-browsertype#browser-type-launch
    """
    playwright.selectors.set_test_id_attribute("data-test")
    return {**browser_type_launch_args, "args": ["--start-maximized"]}

Let’s break down the code:

• Fixture Scope: The decorator defines this as a session-scoped fixture. This means it will be executed once per test session, ensuring consistent configuration across all tests.
• Parameter Injection: The fixture accepts two parameters: A dictionary containing the original launch arguments. The Playwright instance, allowing access to Playwright-specific configurations.
• Test ID Configuration: The line configures Playwright to use the data-test attribute for test ID selectors. This enables the use of the more concise method in tests, enhancing readability and maintainability.
• Window Maximization: The fixture adds the “—start-maximized” argument to the browser launch arguments, ensuring that the browser window starts in a maximized state for all tests.
• Return Value: The fixture returns an updated dictionary of launch arguments, combining the original arguments with the new maximized window setting.

Test Usage

The test usage can be found here.

With the test ID attribute configured, we can now use Playwright’s method for more intuitive element selection. Here’s an example of how this improves our test code:

import pytest
from playwright.sync_api import Page, expect

from enums.User import User

class TestInventory:

    @pytest.mark.parametrize(
        "browser_context_args", [User.STANDARD_USER], indirect=True
    )
    def test_inventory_page(self, browser_context_args, page: Page):
        expect(page.get_by_test_id("title")).to_have_text("Products")

Benefits of This Approach

1. Improved Readability: By setting up the test ID attribute and using , we make element selection more intuitive and easier to read, enhancing the overall maintainability of our test code.
2. Alignment with Best Practices: Using test IDs for element selection is a recommended practice in web testing, as it creates a clear separation between testing concerns and application styling or structure.

In Conclusion

Leveraging Pytest fixtures with Playwright provides a powerful way to streamline browser element selection for web application testing. By setting up test ID configurations at the session level, we can ensure consistent, efficient, and maintainable test executions. The use of further enhances our test code’s readability and robustness. This approach not only saves time but also enhances the reliability and maintainability of our test suite, contributing to the overall quality of our testing process.

Happy testing!