Parallel Testing: The Comprehensive Guide

Introduction

As the term suggests, parallel testing means running different tests simultaneously. Parallel testing can be a game-changer for optimizing testing speed while maintaining the same level of test coverage.

In traditional testing approaches, tests are run sequentially, which can be time-consuming and lead to delays in software releases. Parallel tests help reduce these delays.

In this blog, we will discuss more details about parallel testing and also the top test automation tools that support parallel test runs.

What is Parallel Testing?

Parallel testing is the process of running multiple tests simultaneously across different platforms, devices, and browser environments. The goal is to save time, effort, and resources. It is contrary to serial testing, where testers run tests one after the other, which can be time-consuming, especially for large test suites.

How Does Parallel Testing Work?

Parallel testing is where a tester runs multiple tests simultaneously across different test environments, browsers, or devices. It speeds up testing by utilizing resources better and reducing overall test execution time.

Who is involved in parallel testing?

Parallel testing is done by the software testing team. It also involves developers, stakeholders, and project managers.

By working together, teams can ensure that testing is conducted efficiently, defects are identified early, and the software meets the desired quality standards.

Parallel Testing Example

Consider you have an automation test script that checks the sign-in form of your web application. You want to test it on more than 50+ browsers and OS combinations.

Running these tests sequentially would take around 2 hours or more to complete testing just one module (the sign-in functionality). And if you have multiple modules like pricing, contact form, and transactions, the testing time would increase significantly.

However, with parallel testing, you can run multiple tests simultaneously. Let’s say you decide to run three tests simultaneously. The total execution time would be reduced to one-third of the previous time, that is, about 40 minutes, instead of 2 hours.

By running more parallel tests, like four or more, the time required for testing continues to decrease. For example, with four parallel tests, it would only take around 30 minutes.

In simple terms, parallel testing allows you to run multiple tests simultaneously, saving a lot of time compared to running them sequentially.

Advantages of Parallel Testing

Parallel testing offers many advantages, such as,

• Increases Testing Speed: Sequential testing is very time-consuming. But, parallel testing speeds up the testing process by running multiple tests simultaneously.
• Saves Time and Reduces Costs: Using parallel testing, you can test your application across multiple browser, OS, and device combinations at the same time. Also, testers can use cloud-based resources instead of having an in-house infrastructure, which can be costly and time-consuming.
• Increases Test Coverage: You can quickly achieve high test coverage in less time. For example, cross-browser testing.
• Optimizes Your CI/CD Process: Parallel testing is crucial for continuous integration and delivery. It enables running tests simultaneously, allowing developers to test new code updates promptly throughout the SDLC. It offers timely reporting and swift feedback and enhances communication across different teams.
• Improvement of Testing Practices: It helps improve the QA process in your organization because testing at high speed will allow them to test more.

Challenges of Parallel Testing

While parallel testing offers numerous benefits, it also comes with certain limitations that should be considered. Here are some of the key limitations of parallel testing:

• 1. Inter-dependent Tests : When a test relies on the completion of another test, you can not run parallel tests. This limitation arises when you wish to avoid starting a test if a previous test has failed. In such cases, it is important to address the issue that caused the failure before proceeding with additional tests to save time and resources.
• 2. Data Dependencies : Parallel testing can become challenging when multiple tests need access to the same data. This is because each test will attempt to fetch or modify the data simultaneously. Parallel tests must not have dependencies on the same data.
• 3. Infrastructure Limitations : If your infrastructure has a limited capacity for handling tests concurrently, you need to limit test parallelization. Trying to run more tests simultaneously than your infrastructure can handle will lead to test failures and inconsistencies due to insufficient resources.
• 4. Test data management : Managing test data sets can be challenging as you will have to deal with multiple data sets to cover various scenarios. Using a test data management tool can help resolve this.
• 5. Programming expertise : Setting up parallel testing using TestNG and Selenium/Selenium Grid, and configuring it will consume time and require high programming expertise to do so. However, using a codeless testing tool like Testsigma, you can eliminate this time-consuming process, by simply running parallel tests on the cloud, in one click. No setup or no coding expertise is required.

Other challenges might include,

• Testers should focus on the data input and product flow
• Platform limitations like the CI/CD platform could limit test parallelization.
• It requires complete product knowledge.

Best Practices for Parallel Testing

Follow these best practices to ensure your parallel testing is effective,

• 1. Run Autonomous Test Scripts : It is vital to create autonomous tests. Each test should be independent and not rely on the outcome of another test. This is because parallel tests will need to be executed simultaneously.
• 2. Set Up Cloud Infrastructure : For parallel testing, you will need multiple test devices for execution. Investing in all these devices could be costly. Instead, you can choose a cloud infrastructure that hosts real device cloud.
• 3. Test One Feature at a Time : Testing one feature at a time is beneficial as it helps you quickly identify failures. This approach is crucial for maintaining the performance of a CI/CD pipeline. Instead of testing multiple features together, focus on individual features, ensuring that any failures are detected promptly.
• 4. Avoid Using Static Objects : It is best to avoid using static objects because they can create conflicts when multiple tests are run simultaneously, as one test may interfere with the object while another tries to manipulate it.
• 5. Keep Tests Similar in Length : It is essential to design tests that have similar durations. It helps ensure that all tests finish around the same time, avoiding situations where most tests are completed while waiting for one slow test to finish.
• 6. Be Strategic & Prioritize : Although parallel testing allows multiple tests simultaneously, there are still limitations on how many tests you can run at once. Instead of running every test case to increase the test coverage, prioritize the test cases. Choose the tests that cover the risky areas of the application in terms of critical functionalities and code complexity. Remember, parallel testing is not a license to run unlimited tests.
• 7. Resetting the test data : To prevent cross-contamination of data, test data should be created, used, and removed. It ensures that the system remains unchanged after the test, just as it was before.

How to Perform Parallel Testing Using Testsigma

Testsigma is a robust cloud-based, no-code GenAI-powered test automation platform that supports parallel testing for web, mobile, desktop, API, and Salesforce apps. How do you automate parallel tests in Testsigma? Let’s discuss this in brief,

• Step 1: Create a free Testsigma account
• Step 2: Go to Test Plans. Create a new test plan or select an existing one.
• Step 3: Once the test machine is added, you can then configure parallel test runs via Settings.

• Step 4: Once it is configured, you can save the configuration using Create or Update Profile.
• Step 5: Click on Run Now to execute these test suites in parallel. Once executed, you will receive detailed automated test reports.

When to Perform Parallel Testing?

You can use parallel test runs in the following scenarios,

• When data is being imported from an older system to a new one, it can be highly beneficial. They help ensure that the data transfer is seamless by using an automated regression test suite.
• When there is a new update for an application that is similar to the previous version, parallel tests can be run to verify different versions of the application. This helps ensure that the new update functions properly and remains consistent with the earlier version.
• Parallel testing is useful when testing a software application across different devices, operating systems, and browsers. It allows for simultaneous testing on multiple platforms, ensuring compatibility and functionality across various configurations.

Top 5 Parallel Testing Tools

Some of the popular automation testing platforms that support parallel testing are as follows,

1. Testsigma

Testsigma is a robust cloud-based no-code GenAI-powered test automation platform that allows users to automate web, mobile, desktop, API, and Salesforce apps in one place.

You don′t have to write any code scripts to run tests. You can simply create automated tests in plain English using the NLP engine or Recorder. It supports parallel testing on the cloud and on local devices, too. You can run your tests across 3000+ browsers, OS, and device combinations using the real device cloud. Automate your entire functional testing process for different application types in the same platform.

Key Features

• A one-click free sign-in to access the cloud platform. No setup or infrastructure is required.
• Get significant test coverage using Copilot, a GenAI test assistant for QA teams, which provides automated test cases and scenario suggestions based on user prompts.
• Makes your test automation process 10x faster, speeds up the release cycles, and reduces time-to-market.
• AI-powered auto-healing helps prevent test failures and reduces test maintenance challenges by up to 70%.
• Supports continuous testing with CI/CD integration.
• Automate even complex workflows in plain English using low-code or codeless techniques.
• Supports both codeless and code-based testing. You can create custom test scripts using Java.
• Provides built-in test review management feature
• Get automated test reports after every test run

2. Katalon

Katalon TestOps introduced parallel execution for test suites in 2021. This feature allows you to run multiple test suites simultaneously across different test environments, resulting in faster and more efficient testing.

Check here - Katalon Alternatives

Katalon TestOps eliminates the need to run test suites sequentially, saving time and effort. With parallel execution, you can distribute test suites, reduce execution time, and achieve faster and more accurate results with minimal effort.

Check here - LambdaTest vs Katalon

Top Features

• A No-Code test automation platform
• Supports various third-party integrations
• Supports web, mobile, and API testing

Check here - Katalon Vs Selenium

3. TestComplete

TestComplete by SmartBear is a test automation platform that supports parallel testing. You can run functional tests in parallel on the cloud or your local machines for continuous testing and delivery.

Check here - Smartbear Alternatives

Top Features

• Automate your testing for web, mobile, and desktop apps
• Supports scriptless testing
• Has record and playback feature
• Faster test execution
• Integrate automated tests into your DevOps pipeline

Check here - TestComplete vs Selenium

4. Selenium

Selenium allows you to run multiple tests simultaneously on different environments, browsers, and devices instead of running them sequentially. TestNG, an automation testing framework, helps run tests in parallel.

Check here - Selenium Alternatives

TestNG makes parallel test execution easy. You can efficiently organize tests and maintain the test case readability. You can define parallel attributes in the testing.xml file.

Top Features

• Selenium supports multiple programming languages like PHP, Java, JavaScript, Perl, Ruby, Python, and more.
• Supports only web application testing
• Provides multi-browser and multi-language support
• It is open-source and available for free
• It is a code-based testing platform

To build and execute tests in Selenium, you will have to download prerequisites like Java, IDE, and other frameworks.

Check here - Selenium Vs Testim

5. Kobiton

Kobiton is a cloud-based testing platform that allows you to test your mobile applications. It supports parallel testing that lets users run concurrent tests across different platforms, devices, and browser combinations.

Top Features

• Allow you to automate mobile app testing
• Test on various real devices
• Provides real-time app analytics
• Supports scriptless test automation

Takeaway

Instead of running tests sequentially, run them in parallel to cut down the execution time. Parallel testing is crucial for shipping products at lightning speed without compromising the quality of testing. With Testsigma, you can effortlessly create, manage, and execute tests on the cloud using no-code and GenAI.