Different Types of Functional Testing - Explained!

Author: Bug Raptors

In this blog, we explain the different types of functional testing in detail.

1. Unit Testing

Unit testing is a software testing type in which testers test the software's individual units or components. The purpose of performing unit testing on the software is to validate each unit of the software code works as expected. Developers get the unit test done during the development phase and verify its correctness of each unit. A unit can be an individual module, object, function, or a method used in the application.

Popular automated unit testing tools are TestNG, Symfony Lime, NUnit, xUnit.net, JUnit, RSpec, Test Unit, and PHPUnit.

Several techniques used for unit testing are as follow:

  • Branch Coverage.
  • Statement Coverage.
  • Boundary Value Analysis.
  • Decision Coverage.
Benefits of Unit Testing

When you hire unit testing services from the functional testing company, you can expect the given benefits:

  • It eliminates bugs or defects in the newly developed features or when any changes are made in the existing functionality.
  • It supports code refactoring and helps improve the design of the product/software or application.
  • While integration with build, unit tests ensure the quality of the build too.
  • One can easily capture defects in the very early phase and can save a lot of money.
2. Component Testing

The other software testing type is component testing. It again requires the experienced functional testing service provider who knows how to test each individual component separately and without combining other components. It also refers to module testing from an architecture perspective. Some people call component testing as module testing, unit testing, and software testing.

Component testing may be used to verify both functional and nonfunctional features of system components. It can help test the performance, structure, and resource behavior (e.g., regulating memory leaks).

Techniques used for Component Testing
  • CTIS (Component Testing in Small).
  • CTIL (Component Testing in Large).

CTIS

In this process, testers perform the component testing in isolation with other components. Integration with other components is not necessary.

CTIL

It is a process in which testing is performed without isolation with other software components. It is not possible to isolate if there is a dependency on the functional flow of components.

Benefits of Component Testing

There are numerous benefits of component testing. Some of them are as follow:

  • It helps in minimizing the project’s cost.
  • It reduces the development cycle time.
  • It supports faster delivery.
  • Finding the defects in the module and verifying the software functionality is extremely easy.
  • It increases the productivity level and provides several benefits when considering the reusability of software.
  • Due to previously tested components, getting reliability for systems is possible.
3. Smoke Testing

Smoke testing is a type of software testing called Build Verification Testing, which includes a non-exhaustive set of tests to run the functions correctly. After obtaining a result from this testing, the functional testing service provider decides further testing phases when they have confidence that a build is stable enough.

Moreover, the testing company decides whether it is essential to announce a production release or need to wait for some time. The word smoke testing is taken from a similar form of hardware testing to software testing where the system needs to pass the test if it fails to catch fire or smoke for the first time.

Features of Smoke Testing

Based on the research, we find out some features of smoke testing that you can check below:

  • Smoke testing is scripted and documented.
  • Smoke testing is a kind of regression testing.
  • Smoke testing may be stable and unstable.
The objective of Smoke Testing

If you are looking for functional testing services, don’t forget to get smoke testing because it is performed with the given objectives:

  • Discover any early defects in software products.
  • Demonstrate or measure the stability of the system/ software product and conformance to requirements.
  • To test the entire function of the software product.
  • Ensure that the program’s acute functionalities are working fine.
Benefits of Smoke Testing
  • Easy to perform.
  • Enhance the system’s quality.
  • Minimizes the risk of failure.
  • Identify defects in the early stages.
  • Time-saving & effort saving.
  • Reduces integration risks.
  • Easy to detect critical errors and make an immediate correction.
4. Integration Testing

It is a testing type that focuses on checking how data is communicated well amongst various modules. In integration testing, software modules are tested as a group and integrated logically. It is known as thread testing, string testing, I & T (integration and testing). Integration testing aims to expose faults when the interaction is made between integrated units. Test drivers and test stubs help get the integration test done efficiently. It is the second level of testing that testers perform after Unit testing and before System testing.

When you hire a tester for functional testing, a wide variety of strategies consider by testers, but the main ones are:

  • Big Bang Approach.
  • Incremental Approach - It is further categorized into the Top-Down Approach, Bottom-Up Approach, and Sandwich Approach that is a combination of top-down and bottom-up methods.
Benefits of Integration Testing
  • Faster development.
  • Easy integration between different modules.
  • Easy tracking and high code coverage.
  • Helps in creating real-time use cases.
  • Top-down or bottom-up integration testing performs at the early stages of software development, and it is easy to capture bugs.
  • Easy to detect system-level issues such as integration mistakes and broken databases.
  • Tests run faster compared to end-to-end testing.
5. Regression Testing

Regression testing is carried out to validate that existing features will never get affected after making a change in code or a current program. It guarantees that the old code will work fine even after adding the latest code in the application. It is a partial or full selection of already performed test cases that testers can re-execute anytime to check the working condition of existing functionalities.

Best regression testing tools are Rational Functional Tester (RFT), Quick Test Professional (QTP), and Selenium.

Benefits of Regression Testing
  • Increase more test coverage in a limited time period
  • Cost-effective & increase efficiency
  • High-quality software
  • Easy to upgrade the software
  • Timely intervention
  • Detect the problematic bugs earlier
6. Sanity Testing

Testers perform this software testing after receiving a software build, making minor changes in functions and codes. Furthermore, the company ensures that bugs are fixed properly, and there will be no issues due to these changes. The purpose of sanity testing is to determine that the proposed functions work as expected. It verifies the rationality of the system to continue with more rigorous testing.

Features of Sanity Testing
  • A subset of regression testing.
  • Not documented.
  • Unscripted.
  • Performed by testing teams by using a narrow and deep approach.
Benefits of Sanity Testing
  • One can quickly discover defects and bugs in the core functionality.
  • In case of finding faults during sanity testing, you can reject a project that saves your time for implementing regression tests.
7. System Testing

The functional testing company performs system testing to ensure that end-to-end system specifications will evaluate carefully. Basically, you can understand software as one element of a larger computer-based system, and it is interfaced with several other hardware or software systems.

It is a black-box testing technique used to check the complete system’s compliance against specified requirements. System functions are tested from an end-to-end perspective. The main focus is given on external interfaces, security, recovery, complex and multi-program functionalities, performance, installability, documentation, load/stress, and application usability while testing.

Common Process to follow for System Testing
  • Develop a test plan.
  • Create test cases.
  • Choose Test Data.
  • Execute test cases.
  • Reporting of bugs and fixation.
  • Repeat the test cycle (if necessary).
Benefits of System Testing
  • It checks whether the app is working correctly from the user’s point.
  • It specifies how the app should behave.
  • Tests can run with automated testing tools to complete all the tasks on time.
  • It helps you know that there is no bug produced in the part of the application where you’ve made changes.
8. User Acceptance Testing

Both clients and end-users can perform UAT (User Acceptance Testing) to accept the software system before moving it to the production environment. This type of testing is conducted when functional, integration, and system testing are done.

User acceptance testing aims to validate end-to-end business flow and doesn’t give importance to spelling mistakes or cosmetic errors. It is also called black-box testing due to the involvement of two or more end-users. Testers use Watir and Fitness tools for user acceptance testing.

Pre-Conditions for UAT (User Acceptance Testing)
  • Check whether the app’s code is fully developed or not.
  • Unit testing, system testing, integration testing, and acceptance testing should be performed first by QA teams.
  • One should complete regression testing and fix all the defects.
  • Keep ready an effective UAT environment.
  • Have a UAT checklist in hand before testing.
  • Ensure that a traceability matrix should be issued.
  • It is necessary to send a sign-off mail to the system testing team.
Benefits of UAT Testing
  • Everyone will be benefited after UAT testing of the software because the quality criteria of the product are met in the early phase of development. Client requirements are satisfied, and help them to check the product in the real environment.
  • Vendors improve their communication with consumers and the team & ensure that the product’s specifications are improved and approved by the customer through approval tests.
  • Engineering teams are free from hassle during the deployment.
  • Stakeholders utilize the information that is collected through UAT and understand it quickly to fulfill the needs of target audiences.
Conclusion

Functional testing is critical to ensure that software/product works as per the customer’s expectation. It is safe to use and offers quality services. If any software or app's function does not work appropriately, your users will take just a few seconds to say goodbye to your product. Therefore, it is essential to know the importance of functional testing types which are mentioned above. Always hire experienced functional testers to run your application at the right time because the right person can only give you the right solution.