The main objective of unit testing is to ensure that each individual part is working well and as it’s supposed to work. The entire system will only be able to work well if the individual parts are working well. Unit testing is performed by the software developers themselves. Sometimes, independent software testers also perform these tests.
There are two main types of unit testing: manual and automated. The automated method is the most preferred as it is faster and more accurate, but performing this task manually is also an option. The manual approach has a step by step instructional procedure that helps testers perform this task efficiently. The automated unit testing usually involves the developer first writing a section of the code in the application so that the function can be tested.
After that, when the application is deployed, they remove the test code. They can also isolate the function to test it in a more thorough way. This helps with identifying any dependency that might be there between the tested code and the other data spaces. These dependencies can then be eliminated.
Unit testing, a testing technique using which individual modules are tested to determine if there are any issues by the developer himself. It is concerned with functional correctness of the standalone modules.
The main aim is to isolate each unit of the system to identify, analyze and fix the defects.
Reduces Defects in the Newly developed features or reduces bugs when changing the existing functionality.
Reduces Cost of Testing as defects are captured in very early phase.
Improves design and allows better refactoring of code.
Unit Tests, when integrated with build gives the quality of the build as well.
Black Box Testing - Using which the user interface, input and output are tested.
White Box Testing - used to test each one of those functions behaviour is tested.
Gray Box Testing - Used to execute tests, risks and assessment methods.
Okay, so software unit testing is great, but how much test coverage is necessary? American software engineer Robert C. Martin, also known as Uncle Bob, argues that the goal of test coverage should be that 100 percent of the code is covered. Opinions among developers on this issue differ: some support a complete code coverage policy, while others consider this practice redundant — a topic too lengthily for the purposes of this article. In any case, when writing unit tests, you can use many tools that determine the total percentage of the coverage of a project, separate module, or function. These tools are also able to graphically display the code sections covered by tests and indicate the sections in the code for which it makes most sense to write unit tests.
It’s very useful to know at the active code writing stage if a particular line will ever be executed or you if can painlessly remove it. If you have valid unit tests, you can have coverage metrics on hand right away, and decide whether a code line is ever relevant. If it’s not, consider expanding your code coverage with one more test. If your test suite already accounts for all possible scenarios, eliminate the unnecessary code. However, the need for more tests is a sign of increasing cyclomatic complexity.
