Add Playwright Backend Support to Galaxy Browser Automation Framework

Introduced comprehensive Playwright support alongside Selenium, enabling runtime selection between frameworks while maintaining full backward compatibility through a protocol-based architecture.

galaxytestingplaywrightseleniumbrowser-automationpython

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The Pull Request

This PR represents a significant modernization of Galaxy’s browser automation testing infrastructure by adding full Playwright support while maintaining 100% backward compatibility with the existing Selenium-based tests.

Technical Approach

The implementation centers on a protocol-based architecture that abstracts browser operations:

HasDriverProtocol and WebElementProtocol interfaces define approximately 61 browser operations
HasPlaywrightDriver class (1,134 lines) provides a complete Playwright implementation mirroring the Selenium API
PlaywrightElement wrapper enables element interactions through the same interface as Selenium
Proxy pattern via HasDriverProxy allows seamless backend switching without modifying existing tests

Testing & Validation

Comprehensive testing ensures reliability:

150+ parametrized unit tests validating all protocol methods
Three test configurations: Selenium, Playwright, and proxy-Selenium
Updated 57 test files with 268+ test methods for Playwright compatibility
CI integration with dedicated GitHub Actions workflow
Runtime backend selection via GALAXY_TEST_DRIVER_BACKEND=playwright environment variable

Impact

Scale: +8,038 −624 lines across 157 files, 51 commits

This work enables Galaxy to:

Leverage Playwright’s modern browser automation capabilities (faster execution, better debugging)
Gradually migrate from Selenium without breaking existing tests
Run tests with either backend based on specific needs
Future-proof the testing infrastructure as browser automation evolves

Personal Notes

This was a challenging refactoring that required deep understanding of both Selenium and Playwright APIs. The protocol-based approach proved essential for maintaining compatibility while introducing modern tooling. The parametrized testing strategy gave me confidence that both backends behave identically.

The most interesting technical challenge was ensuring the proxy pattern correctly delegated all operations while maintaining proper typing through Python protocols. The result is a clean abstraction that other projects could adapt for similar dual-backend scenarios.

Labels & Milestone

Labels: area/testing, area/testing/selenium, area/UI-UX, area/objectstore, area/packaging

Milestone: 26.0

Status: Open (ready for review)

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