Running automated browser testing in parallel is not that easy, even with Selenium Grid, and it happens due to the unstructured automation framework that you use for parallel test execution in Selenium. Here are some best practices that can help you execute [Selenium test automation](https://www.lambdatest.com/) in parallel successfully.
1. Generate Independent Test Cases
If you generate independent tests that can run on their own, then it will be easier for you to execute them in parallel. In simple words, the tests need to be self-contained. So, when you run any test, you don’t have to worry about the order in which you run your test suite.
Sometimes, tests in parallel execution exhibit invalid behavior like failing when it shouldn’t or failing when it shouldn’t, which is known as flakiness. Independent tests can reduce the flakiness in the automated browser testing process by decreasing the number of possible breaking points in a test. Another significant advantage of using independent tests is that if one fails, it won’t stop you from testing other testing functionality.
2. Parallel Testing Using Cloud-Based Selenium Grid
Perform Automated browser testing on your local Selenium Grid can be exhausting, as not only you have to manage and maintain all the machines, but also to set them as well. Parallel testing on a local Selenium grid will have some scalability issues as you won’t be able to cover all the major browsers, their different versions, and OS.
With a cloud-based Selenium Grid, you don’t have to worry about setup anymore. With LambdaTest Selenium Grid, you can run parallel tests on 2000+ real browsers and their different versions. You’d not only save a lot of money on setting up the infrastructure but also you’d get ample time to do tasks that matter.
3. Avoid Hard Code values
Most testers have to run their tests in a particular order due to hard code embedded directly in the source code. This approach doesn’t allow you to run tests in parallel efficiently, as it creates dependencies between test cases.
So, avoid hard code values in your Selenium test automation scripts to ensure that each of the tests is independent and can be executed whenever necessary. You can even opt for a data-driven approach in the testing framework to configure the test cases.
4. Prevent Dependencies Between Selenium test automation Cases
Many testers often find it challenging to execute tests in parallel due to dependencies between various test cases. When tests are dependent on each other, they need to be run in a particular order, which often affects the parallel testing strategy. So, you should focus on creating independent and atomic tests that can be executed independently.
5. You Need To Manage Your Test Data Efficiently
The primary key to successful parallel Selenium test automation is handling the test data efficiently. But to achieve this, you need an effective strategy that can create test data when required, as well as clean it up when necessary. Below are some basic data management strategies that can be very effective.
- Refreshing data continuously – this approach allow you to reset your source code during test executions.
- Using RESTful API – it is a great way to create and destroy data during runtime.
- Selfish data generation – this approach has a creational strategy but doesn’t offer anything for data cleanup. These are just a few approaches that can be used to manage test data effectively. You can even combine two approaches in order to attain the desired output.
The best approach to execute tests in parallel is to create different projects for browser compatibility testing various parts of a web application, and a master project to test those different projects. Generally, there are two-level criteria for parallel testing in Selenium. The first one is Entry-level criteria and the other one is Exit criteria.
In entry-level criteria, specific tasks are defined that should be satisfied before executing tests in parallel successfully, such as :
- A testing environment setup is required before starting parallel testing in Selenium
- Pre-conditions and scenarios must be defined before starting the automated browser testing process
- New data and legacy data must be migrated successfully
The Exit level criteria describe the steps for executing parallel testing successfully, which includes:
- Running old system against newly developed systems
- Understanding the difference between both systems
- Going throw complete automated browser testing cycle while using the same input
- Measuring the output of a newly developed system as compared to the old system
- Reporting bugs (if any found) to the development team
A parallel testing approach can only be successful if you use the best practices to implement it. Below are some effective approaches that you can use to implement parallel testing in Selenium.
Best Practices for executing parallel tests:
- Generate Independent Test Cases
- Parallel Testing Using Cloud-Based Selenium Grid
- Avoid Hard Code values
- Prevent Dependencies Between Selenium test automation Cases
- You Need To Manage Your Test Data Efficiently