Introduction to Unit Testing and its Advantages
In this article, let’s look at the advantages of unit testing. It is recommended that automation engineers learn unit testing, though unit tests are developer tests.
What is Unit Testing?
First things first, Let’s answer the question. Unit testing refers to testing units of code. Therefore, it ensures that a particular unit of code successfully performs a set of specific intended tasks as per the specification. The unit of code in an object-oriented perspective would be a class and its methods. Unit tests are those tests that developers write to verify that the classes and methods function as expected. Also, they are written from the developer’s point of view. Furthermore, each test confirms that a method produces the expected output when given a known input to it.
The picture below shows that a test method takes a known input and interacts with the class under test. The test pass or fail criteria depends on the output of the interaction.
Advantages of Unit Tests:
First of all, the cost of fixing a defect uncovered during unit testing is much less in comparison to that of defects uncovered at higher levels of testing.
Unit tests give the developer a high degree of confidence in the product. Also, if the developer has to modify the code, the unit test suite is the tool to verify that no existing functionality has been broken.
It makes source code more reusable. Source code needs to be modular, in order to make unit testing possible.
Refactoring code to improve the quality can be easily done with the knowledge that the unit tests will demonstrate the correctness of the refactoring.
Documentation is always kept up-to-date.
In conclusion, the whole idea of unit testing is to write test cases for all functions and methods so that whenever a change causes a regression, it can be quickly identified and fixed with less cost and effort.
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