When using a custom Playwright-Python browser context, how to take fail case screenshots using Pytest?

Are you tired of debugging issues in your Playwright-Python browser context without a visual clue? Do you struggle to identify the root cause of failures in your automated tests? Worry no more! In this article, we’ll show you how to take fail case screenshots using Pytest, making your testing experience more efficient and effective.

Why Take Screenshots in Pytest?

Taking screenshots in Pytest is an essential feature for debugging and troubleshooting issues in your automated tests. By capturing the screen at the moment of failure, you can:

• Visualize the issue: A screenshot provides a clear visual representation of the failure, making it easier to identify the problem.
• Reduce debugging time: With a screenshot, you can quickly pinpoint the issue, reducing the time spent on debugging.
• Improve test reliability: By analyzing the screenshot, you can identify flaky or intermittent issues, leading to more reliable tests.

Prerequisites

Before we dive into the implementation, ensure you have the following:

• Pytest installed (version 6.2 or higher)
• Playwright-Python installed (version 1.20 or higher)
• A custom Playwright-Python browser context set up

Implementing Screenshot Capture in Pytest

browser_context and page objects provided by Playwright-Python. Here’s an example implementation:

import pytest
from playwright.sync_api import sync_playwright

@pytest.fixture
def browser_context():
    with sync_playwright() as p:
        browser = p.chromium.launch()
        context = browser.new_context()
        yield context
        context.close()
        browser.close()

@pytest.fixture
def page(browser_context):
    page = browser_context.new_page()
    yield page
    page.close()

In the above code, we define two fixtures: browser_context and page. The browser_context fixture launches a new Chromium browser instance and creates a new context, while the page fixture creates a new page object using the browser_context. We’ll use these fixtures to capture screenshots.

Capturing Screenshots on Failure

To capture screenshots on failure, we’ll use Pytest’s built-in @pytest.fixture decorator with the autouse=True parameter. This will allow us to run the screenshot capture code automatically on test failure.

@pytest.fixture(autouse=True)
def capture_screenshot_on_failure(request, page):
    yield
    if request.session.testsfailed:
        screenshot = page.screenshot(path='screenshot.png', full_page=True)
        print(f"Screenshot saved to {screenshot}")

In this code, we define a new fixture called capture_screenshot_on_failure. The autouse=True parameter ensures that this fixture runs automatically on test failure. We use the page.screenshot() method to capture the screenshot, saving it to a file named screenshot.png in the current working directory.

Configuring Pytest to Use the Custom Fixture

To use our custom fixture, we need to configure Pytest to include it in the test run. You can do this by creating a conftest.py file in your test directory:

[pytest]
addopts = --fixtures_capture_screenshot_on_failure

This configuration file tells Pytest to include our custom fixture in the test run.

Running Your Tests with Screenshot Capture

Now that we’ve set up our custom fixture and configured Pytest, it’s time to run our tests:

pytest -v test_file.py

When a test fails, Pytest will automatically capture a screenshot and save it to the specified file. You can then analyze the screenshot to identify the root cause of the failure.

Tips and Variations

Here are some additional tips and variations to enhance your screenshot capture experience:

Customizing the Screenshot File Name

You can customize the screenshot file name by using the request.node.name attribute, which provides the test name:

screenshot = page.screenshot(path=f"{request.node.name}.png", full_page=True)

Capturing Screenshots on Specific Failures

If you only want to capture screenshots for specific failures, you can add additional logic to the capture_screenshot_on_failure fixture:

if request.session.testsfailed and request.node.name.startswith("test_login"):
    screenshot = page.screenshot(path='screenshot.png', full_page=True)

Uploading Screenshots to a Remote Server

You can upload the captured screenshots to a remote server using a library like requests:

import requests
...
screenshot = page.screenshot(path='screenshot.png', full_page=True)
response = requests.post("https://example.com/upload", files={"screenshot": open("screenshot.png", "rb")})

Conclusion

In this article, we’ve shown you how to take fail case screenshots using Pytest when using a custom Playwright-Python browser context. By implementing this feature, you’ll be able to visualize issues in your automated tests, reducing debugging time and improving test reliability. Remember to customize the screenshot file name, capture screenshots on specific failures, and upload screenshots to a remote server to further enhance your testing experience.

Keyword	Description
Playwright-Python	A Python library for automated browser testing
Pytest	A popular testing framework for Python
Screenshot	A visual representation of the browser screen
Browser Context	A customized browser instance for testing
Fixture	A setup and teardown function in Pytest

By following the steps outlined in this article, you’ll be well on your way to creating a more efficient and effective testing experience. Happy testing!

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