Types of Functional Testing Explained & How to Perform It

What is functional testing?

Function testing is an important part of software testing which verifies the software system conforms to the intended functional requirements and specifications. By providing appropriate input and verifying the output against the functional requirements, the main objective of this testing is to validate each function of the software application.

It's worth noting that functional testing mainly involves black-box testing, which means it doesn't require any knowledge of the source code. Functional testing checks various aspects of the software such as user interface, APIs, database, security, client/server communication, and other functionalities of the application under test.

Functional testing can be either manual or automated. In manual testing, the tester executes the test cases manually, while in automation testing, tools are used to execute the test cases automatically.

Types of Functional Testing?

There are many types of functional testing, and we will focus here on the following six most common types:

• Unit testing:

Unit testing involves the developer writing various units of code, which may or may not be related, to achieve some functionality. Unit tests are written to ensure that these code units work as expected. Code coverage is a critical component of unit testing, and it helps ensure that the code units are adequately tested. This means that test cases must cover three areas: line coverage, code path coverage, and method coverage.

• Sanity Testing:

Sanity testing is another essential type of software testing that ensures that all the vital functionalities of the application/system are working correctly. It is usually performed after smoke testing and helps to identify critical issues that may have arisen due to changes in the code.

• Smoke Testing:

Smoke testing, also known as build verification testing, is a type of testing performed after each build is released to ensure build stability.

• Regression Tests:

Regression Tests are performed to ensure that the addition of new code, enhancements, or bug fixes does not break the existing functionality or cause instability. Although regression tests need not be as extensive as the actual functional tests, they should still provide enough coverage to certify the stability of the functionality.

• Integration Tests:

Integration Testing is crucial when the system relies on multiple functional modules that work well individually but must work cohesively when combined to achieve an end-to-end scenario. By validating these scenarios, integration testing helps to identify any issues that may arise when multiple modules are combined.

• Beta/Usability Testing:

Beta/Usability Testing exposes the product to the actual customer in a production-like environment, allowing them to test it. Feedback from users is taken into account, which helps to ensure that the product meets their needs and expectations.

How to do functional testing? A step-by-step guide

After learning the types of functional testing, it also matters to understand how to do it. Here are the steps:

Step 1: Understand the Functional Requirements

The first step to performing functional testing is to gain a deep understanding of the functional requirements. You need to know the scope of testing and determine which functionalities need to be tested. Once you have a clear understanding of the functional requirements, you can move on to the next step.

Step 2: Create Test Cases

To perform functional testing, you need to create test cases that cover different scenarios the software may encounter. These test cases should be designed to validate each function of the software application and verify the output against the functional requirements. Be sure to create a comprehensive list of test cases that will adequately cover all possible scenarios.

Step 3: Identify Test Data

Once you have created the test cases, you need to identify the test data that will be used to validate the software system. It is crucial to choose appropriate test data that will accurately represent the expected input values.

Step 4: Execute Test Cases

With your test cases and test data identified, it's time to execute the test cases. You can do this either manually or by using automation tools. Here the APP Functional Testing can be trusted. WeTest understands the challenges that come with short development cycles and low testing manpower input. That's why it provides customized case design and implementation services to help you strive for full coverage of functional use cases. During the execution of test cases, it's essential to record any defects found in the software system. It's important to test the software system thoroughly to identify any defects or bugs that may affect the software's functionality.

Step 5: Analyze Test Results

After the test cases have been executed, it's time to analyze the results. You need to compare the actual results produced by the software system with the expected outcomes computed during the test case design. Analyzing the results will help you determine whether the software system meets the functional requirements and specifications.

Step 6: Report Defects

The final step is to report any defects found during the testing process, which involves creating a defect report that includes information about the defect and steps to reproduce the issue.