Transition Achieved: Test Automation Changeover from Capybara to Cypress in a React-and-Rails Software
In a commercial Ruby on Rails project, the team embarked on a significant shift, transitioning from the Capybara end-to-end (E2E) testing library to Cypress. This change aimed to enhance test reliability, developer experience, and UI visual testing while facing challenges around skill shift, integration complexity, and resource demands.
### Benefits of Transitioning to Cypress
The team found that Cypress offered several advantages over Capybara. Cypress is known for its speed and reliability, providing quick feedback during development cycles, accelerating the test development and maintenance process. The intuitive interface for writing tests, including a rich GUI for test execution and debugging, can enhance productivity compared to Capybara's more code-driven approach.
Cypress also offers real-time reloads, automatically reloading tests on file changes, and advanced debugging tools, such as time-travel debugging and inspecting elements and commands directly in the browser, simplifying the identification of test failures. Additionally, Cypress tests are written in JavaScript, aligning well with modern front-end stacks, and offering more direct control over browser behavior and network requests.
Cypress also integrates well with various visual testing tools, such as Percy, for detecting visual regressions in UI, improving test coverage for UI consistency.
### Challenges of Transitioning from Capybara
One of the main challenges of transitioning from Capybara to Cypress is the language and ecosystem shift. Capybara tests are typically written in Ruby within the Rails environment, whereas Cypress uses JavaScript. This requires the team to adopt or strengthen JavaScript/testing skills, potentially increasing initial ramp-up time.
Integrating Cypress into existing Rails projects, which are predominantly Ruby-based, may involve additional setup effort, including managing separate test suites and CI pipelines for JavaScript-based tests. Cypress primarily runs in Chrome-family browsers, which may limit testing in other browsers or environments without additional tools.
Asynchronous handling differences between Capybara and Cypress may also require rewriting tests carefully to avoid timing issues or flaky tests. Cypress runs a full browser instance during tests, which can be more resource-intensive compared to some Capybara drivers, impacting CI run times or local testing speed.
### Summary Table
| Aspect | Capybara | Cypress | |-----------------------------|------------------------------------------|--------------------------------------------| | Language | Ruby | JavaScript | | Test Writing Style | Simulates user interaction via DSL | JS-based with GUI support | | Speed | Moderate (depends on driver) | Fast and reliable | | Debugging | Logs and screenshots | Time-travel debugging, GUI inspection | | Browser Support | Multiple via drivers (Selenium, headless) | Mainly Chrome-based browsers | | Integration with Rails | Seamless, native Ruby ecosystem | Requires bridging JS tests with Rails app | | Visual Testing Integration | Supported but less integrated | Strong integration with tools like Percy | | Learning Curve | Easier for Ruby developers | Requires JS knowledge, new tooling |
### Successful Transition and Results
Despite the challenges, the team successfully transitioned to Cypress. The initial CI build time decreased from nine minutes for 109 Capybara scenarios to seven and a half minutes for 419 Cypress scenarios, despite having almost four times more tests. The testing suite included 110+ scenarios and was fired on the Continuous Integration server each time a new commit was pushed to the branch.
The team moved their workflow towards continuous delivery, being able to deploy any fix or feature to production thanks to their powerful test automation solution. The team built confidence in the test suite by removing flaky tests and writing Cypress E2E integration tests for every new feature delivered to the end user.
Changes in architecture required model restructures and data migration, causing extra maintenance for the test suite. However, the team spent hours on fixing code review requests and learned how to collaborate on shared code and contribute to others' work. The team's QA daily work changed significantly, with tests being written locally and bugs being found before any code got to a stable testing environment.
The product was an accounting web application for a small business, and the team's efforts resulted in a more reliable, efficient, and user-friendly application. The transition from Capybara to Cypress demonstrated the team's commitment to continuous improvement and their ability to adapt to new technologies in order to deliver the best possible product to their clients.
- The team discovered that Cypress, a JavaScript-based testing library, provides faster feedback during development cycles and streamlines the test development and maintenance process, due to its speed and reliability.
- In contrast to Capybara's code-driven approach, Cypress offers an intuitive interface for writing tests, complete with a rich GUI for test execution and debugging, which can boost productivity.
- Cypress offers real-time reloads, automatically reloading tests on file changes, and advanced debugging tools like time-travel debugging and inspecting elements and commands directly in the browser, making test failure identification simpler.
- Integrating with visual testing tools like Percy, Cypress improves UI test coverage for UI consistency by detecting visual regressions.
- Transitioning from Capybara to Cypress requires a shift in language and ecosystem, as tests in Cypress are written in JavaScript, necessitating the team to enhance their JavaScript/testing skills.
- Integrating Cypress into existing Rails projects may involve separate test suites and CI pipelines for JavaScript-based tests, creating additional setup effort and bridging the gap with the Rails app.
- The product, an accounting web application for a small business, benefited from the team's transition to Cypress, resulting in a more reliable, efficient, and user-friendly application, demonstrating the team's commitment to continuous improvement and adaptability to new technologies.
