Guide To Functional Testing & Type of Functional Testing

Guide To Functional Testing & Type of Functional Testing

Written by Kartikey Saraswat, In Cyber Security, Published On
March 11, 2023

What is Functional Testing?

Functional testing involves testing the fundamental capabilities of an app against a set of predefined requirements. Functional tests, which employ Black Box Testing methods, check to see if a given input produces the expected result. Passing or failing tests are the only possible outcomes.

Importance of Functional Testing

Functional tests help developers understand if their application’s performance meets expectations. Although the program may pass all the non-functional tests and run smoothly, testers can deem your app as “not working” if it fails to provide the essential deliverables to the end user.

Functional and Non-Functional Testing

Functional tests ensure that the application’s intended functionality is present and correct, whereas non-functional tests examine the application’s other features, such as speed, security, scalability, and overall quality. So, functional testing primarily checks whether or not an app’s critical features are available, while non-functional testing is more interested in seeing the system’s actual behavior under test.

Functional Testing Types

Functional Testing Types

The term “functional testing” encompasses various activities, from testing individual components to re-testing previously implemented functionality. Organizations have found success implementing these tests into their SDLC

1. Unit Testing

Developers conduct this form of testing while they create the software. By verifying that a specified set of inputs always produces the expected results, unit testing confirms that a piece of software is working as intended. This vital test lays the groundwork for subsequent, more comprehensive, integrated, and complex tests.

2. Module or Component Testing

Component testing is comparable to unit testing because both focus on validating individual pieces of functionality. However, component testing at this stage might require the app to interact with sample test data, often known as a stub and driver.

3. Integration Testing

QA teams must ensure that the modules and components work together, even if they have passed the individual tests. Modules and components of a system are often developed independently by multiple teams, making integration testing crucial to ensure they function as intended.

Microservices are a common part of today’s interconnected software architecture. Integration testing should cover verifying the appropriate functioning of these communications.

4. System Tests

In this stage, we test the software as an entire system to ensure it satisfies our operational and strategic needs. Also known as end-to-end testing, this phase typically precedes User Acceptance Testing.

For reliable results, system testing necessitates a test environment that accurately simulates the live setting. In addition, testers carry it out using the white-box testing approach, in which the testers do not know how developers built the system.

5. Regression Testing

Adding new features to software can impact existing functionalities. The software must undergo regression testing to ensure its proper operation every time developers make changes. Since regression testing is labor-intensive, testers prefer to automate it.

6. Sanity Tests

Sanity tests are similar to regression tests; however, in contrast to regression testing, which examines the overall app system after developers make changes, sanity testing focuses on the parts of the system where the addition of new code or the elimination of bugs has changed. Testers will perform no further testing on the build if it fails the sanity check.

7. Smoke Tests

QA teams perform smoke testing once developers complete a fresh build. They test the essential features during this stage to ensure the app provides the expected outcomes. Smoke tests, a variation of acceptance tests, help QA teams assess the build’s performance. Based on the performance results, the teams can decide if they must start the next testing phase.

Functional Testing Automation

The final step before releasing a product is software quality assurance. Because of its importance to income and competitive advantage, accelerating the process is essential without sacrificing software quality.

The only way to maintain quality while meeting strict release schedules necessitated by the ever-increasing market demands is to automate the testing process.

The use of automated functional testing can significantly reduce error costs. Teams implementing test automation can test faster and more efficiently, catch issues early, and improve TOI.

Functional testing automation improves efficiency, communication, and oversight amongst teams. Software testing platforms like HeadSpin can help you make quick decisions and build well-rounded apps. You can leverage detailed reports, comprehensive dashboards, and actionable insights to fix issues and improve app performance. Its device cloud gives you access to real devices. You can connect and test these devices from any location worldwide.

Instead of mundane tasks, quality assurance specialists can focus on creating novel testing scenarios, running exhaustive unit tests, simulating edge cases, and doing exploratory testing.


All software testing frameworks must include functional testing. It ensures that, in real-time, a system performs as expected. Because testers perform it from the end user’s perspective, functional testing ensures that the final product fully satisfies the target audience’s needs and leaves the user with a positive impression. Developers and organizations alike will appreciate the convenience this provides.

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