The system of every software product consists of different elements that form modules, levels and subsystems. Each such element ensures the proper functionality of the whole system. All constituent parts of the product system are interrelated and interconnected.

The high quality of the software program is ensured by thorough software testing that can check either separate system level (module testing, integration testing) or the whole system (functional testing, system testing).

Module testing or unit testing is executed in order to verify the proper work of every particular system element. Unit or module is the minimal program component that can be tested. This can be a feature, method, function, etc.

What Is the Specifics of Unit Testing?

• This checking type includes white box testing techniques and is performed before integration testing.
• Unit checking cover positive test cases as well as negative ones.
• It is executed at the early stages of software development and as a result it reduces the cost of detected bugs.
• There is a low possibility that the process of bug fixing will affect the work of other elements as the test cases check only one separate feature.
• The creation and maintenance of unit tests are rather easy.
• It ensures an easy checking of the product code as the test volume is not large and only one particular component is tested.

A set of special tools for unit testing is available. These tools will provide effective and efficient testing of system modules. Often the specialists use such tools as JUnit (Java framework), PHPUnit (PHP framework), .Net, etc.