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Cedric Muuo
Cedric Muuo

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Designing a Testing Strategy using the Test Pyramid

If you are planning to kickstart or improve software testing in your system and are looking to venture more into automation rather than manual testing, then look no further. In this article, I will discuss the Test Pyramid in-depth and help you understand its core foundations and why they are valuable in automation testing.

Testing Pyramid

As displayed above, the Test Pyramid is simply a 3-layered pyramid that defines the types of tests to be included in your test plan, the sequence of the tests, and the frequency in which they will be run. The most outstanding benefit of using this test automation framework is the efficiency it introduces in the development eco-system. This is because it reduces the time required for developers to identify if a change introduced breaks the code as it looks to offer feedback as soon as possible in the system.

The pyramid is divided into 3 levels:

  1. Unit Tests
  2. Integration Tests
  3. End-to-End Tests(UI Tests)

Level 1 - Unit Tests

They are used to test the individual components and functionalities to validate that they work as expected in isolated conditions. They form the largest subset of the pyramid and in that case, they should be designed to run as fast as possible. Every time a new feature is introduced, this suite is run(which will be quite often in any developing system). As a result, developers will receive immediate feedback on if the introduced change might have had an impact on existing individual components.

In order to build a sturdy unit test suite, it is recommended to use the Test-Driven Development methodology which in summary requires tests to be written before any code hence promoting cleaner, simpler and bug-free code. To read more on TDD and other testing approaches, consider this article TDD vs BDD.

It is important to ensure you build a potent unit test suite as this will be the foundation of the pyramid and is the key to seamless communication in a testing system.

Level 2 - Integration Tests

These tests are used to verify that the individual units can integrate properly with external components or other pieces of code from the software. They also test how a feature communicates with external dependencies such as databases and APIs.

Integration tests are slower to run as compared to unit tests. They should therefore not be run as often as unit tests as you have more features to cover and more testing types to conduct. Note that these tests are run in a production environment.

Level 3 - End-to-End tests(E2E tests)

As the name suggests, these tests ensure that the application is running flawlessly from start to finish. These sit at the top of the pyramid and the most important thing to consider when writing these tests is the user's perspective. How would an actual user interact with the application? How can these tests then be written to replicate this interaction? A good approach to consider when writing these tests is Behavior-Driven Development which in summary describes behaviors in a single notation that is directly accessible to domain experts, testers, and developers consequently improving communication.

Also known as UI tests, these are the most fragile in the pyramid as they test a large variety of scenarios and take the longest to run. In that case, it is advised to run E2E tests only for high-level flows in the application. Like Integration tests, these tests may require the app to communicate with external dependencies resulting in possible bottlenecks in the system

In conclusion, the Testing Pyramid is an effective framework to consider for any QA team due to its array of benefits. The most significant of these being:

  1. Using the Test pyramid introduces a clear progression and sense of logic in the system and this directly improves the speed and efficiency of the process. Time management and communication issues become a thing of the past.

  2. The pyramid gives the testers the right priorities when writing the scripts. Testers will have to verify the unit tests run flawlessly before moving on to the other tests. This will ensure that the back-end functionalities are stable and will save you a lot of time as the features increase.

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