What Is a Testing Pyramid and How to Implement It?

In times of advanced technologies, we all want to use applications easily and perform actions seamlessly. But everyone indeed experienced situations when, for instance, you entered the correct credentials, but the platform didn’t let you access it. Or, when wanting to buy something online, the transactions were constantly failing despite accurate credit card information. Such things not only leave a negative impression of the service but undermine trust in your brand and the quality of your product.

Issues preventing end users from easily interacting with software should be detected and eliminated before production. The best way to cover examining the whole platform and making sure it is bug-free is to implement a pyramid testing strategy. So, let’s discover what this approach offers to quality assurance (QA) teams.

What Is a Testing Pyramid?

If you are interested in software development, you should have heard about different testing techniques, methods, and approaches. However, they are very comprehensive and, if not organized logically, can take up much of your time and resources and leave the product exposed to different issues. That is where the software testing pyramid concept can help.

Presented in 2009 by Mike Cohn in the book “Succeeding with Agile: Software Development Using Scrum”, the testing pyramid sets a foundation for building a reliable and high-quality digital product. This approach refers to hierarchically distributing different testing types, ensuring that efforts are efficiently spent and no bugs go unnoticed.

Test Automation Pyramid: Visual Representation

As the name suggests, the test pyramid is presented by three levels: the first at the bottom is occupied by unit testing, integration testing stays in the middle, and end-to-end (E2E) testing is at the top. These main layers have the following functions:

• Unit testing. The main scope of work in the testing pyramid belongs to unit testing. That means that QA teams will first check if the small software parts work as intended. Unit testing ensures code quality, which is essential for further development cycles.
• Integration testing. Integration testing occurs after the main software modules are checked. It examines how units connect and communicate with each other. Platform parts can function well separately, but if put together, they might not run seamlessly. That is why integration tests are essential to check the system’s performance.

• End-to-end testing. The least number of tests is executed within E2E testing. This procedure identifies platform functionality from the user’s perspective. The end-to-end examination covers all possible user scenarios and is conducted before release. This testing type is an integral part of the testing cycle as it validates the product’s readiness to meet with real users.

Pyramid Testing: Flow of Realization

As mentioned, the test pyramid consists of three testing types. Let’s examine their execution process, examples, and helpful tools.

Unit Test

Unit testing works on a code-level structure. These tests are the most frequent, the fastest to perform, and the largest in number in the test automation pyramid. Software developers conduct unit testing at the early development stages. With this, they check their work and the quality of the written code.

Experts recommend automating running unit tests and implementing them into the continuous integration/ continuous delivery (CI/CD) pipeline. Thus, automatic tests will immediately show any issues when the code changes occur.

Examples of Unit Tests Execution

There are multiple ways for QA teams to run unit testing. The most convenient one is to use frameworks to write and execute tests. Let’s see the examples of PHPUnit and JUnit as popular tools for unit-testing type.

• PHPUnit. This framework is helpful for developers to test code units created based on PHP code. It has beginner-friendly and intuitive syntax for identifying, building, and executing test cases. Rushing forward to check how the units integrate, PHPUnit also offers advanced functions like stubbing or mocking that mimic external dependency behaviors, enabling checking how the units would react to them.
• JUnit. This open-source framework was created to work with Java programming language. JUnit follows the test-driven development (TDD) approach, which suggests writing tests before writing code. The framework is famous for its straightforward interface and comprehensive ecosystem. JUnit is also compatible with the implementation of the CI/CD pipeline.

Integration Test

When all individual platform parts are verified, testers proceed to the next layer: tuning interaction tests. These tests are smaller in number and more complex to execute. QA teams conduct integration testing to ensure that the separate code units communicate with external services and work cohesively in one system.

Unlike unit testing, this testing type is not required to be run frequently. Integration is usually checked after a massive system update or new feature integration.

Examples of Integration Tests Execution

Let’s see what integration testing in the pyramid of testing looks like when implemented for different industries.

• Hotel booking apps. As one example of the integration test, QA teams can check the process of booking a hotel and making a payment. The seamless process will result in the hotel booking being processed successfully.
• Banking apps. To see if the units work together correctly, testers can use the integration testing method to examine if, for instance, the generated bill is correct and delivered to the right person.
• Communication apps. Examining the integration between units in communication apps can be performed by checking, for example, whether the users receive notifications when messages are delivered.

End-to-End Testing

End-to-end tests are the most complicated to execute and are fewer than unit or integration testing. They check every aspect from the user’s side, from entering the platform to successfully buying products or performing actions.

The purpose of E2E testing is to ensure the perfect software functionality and to examine whether it delivers a seamless and intuitive user experience.

Examples of End-to-End Tests Execution

QA specialists use test automation frameworks to execute E2E testing. Here are some popular ones:

• Cypress. This open-source end-to-end testing tool is popular among developers and QA professionals. It is JavaScript-based and easy to use. Cypress has multiple advantages: it runs fast right in the browser; it enables automatic waiting, so you don’t go to further steps without completing previous ones; and it supports a continuous integration model.
• Selenium. The framework operates with JavaScript, Java, Python, and C# languages and supports diverse web browsers such as Chrome, Edge, Safari, and Firefox. It also has multi-language support, is an open-source tool that supports integration with CI/CD, and has a lively community.

Benefits of the Testing Pyramid

Many testers choose to follow a pyramid testing strategy. Here is why this approach is advantageous and popular.

Improved Code Quality and Maintainability with Unit Testing

The concept of pyramid testing dictates the necessity to run unit testing frequently. It helps to stay informed of the code quality, especially when changes are made.

Early Error Detection and Prevention

Thanks to the multi-level nature of pyramid testing, there are fewer chances of missing bugs as the software is tested continuously. Also, this concept suggests implementation from the early development stages, which means discovering issues early and fixing them before deployment.

Faster Feedback and Shorter Development Cycles

The pyramid testing concept allows testers to always be up to date with the software’s performance level and functionality. Thus, with relevant data, developing and testing teams can streamline the development processes.

Reduced Costs for Test Execution

Conducting different tests without a proper structure and expected outcome is costly. But pyramid testing offers a defined hierarchy with clear deliverables that allow testers to plan their budgets wisely.

Final Words

The testing pyramid is a testing model that reduces the complexity of software testing by offering a well-defined and logical structure. It consists of three main testing types: unit, integration, and end-to-end testing. These types cover the most crucial aspects of testing and suggest a coherent plan for its execution.

If you want to ensure your software quality and positive user experience, turn to the professionals in the testing field. At White Test Lab, we understand all the intricacies of testing and provide full-fledged support for projects of any type and complexity.