Unit testing is one of the software testing types which includes the initial testing phase where the smallest components or the modules of a software are tested individually. With this method of testing, both testers and developers can isolate each module, identify and fix the system defects at a very early stage of the software development lifecycle (SDLC). Primarily, a unit test verifies different behavioral aspects of the system under test and can be broadly classified into state-based and interaction-based unit testing.
A typical unit test consists of three phases which include the first initialization phase where it initializes a small piece of an application it wants to test. The second phase is the addition phase where it adds a stimulus to the system under test and finally, the third phase is the result phase where it observes the resulting application behavior. Evidently, if the observed behavior is consistent with expectations, then the unit test passes else it fails. This indicates there is a problem somewhere in the system under test. These three test phases are named Arrange, Act, and Assert or commonly known as AAA.
What are the benefits of Unit Testing?
– Isolates a section of code and validates its correctness
– Helps in identifying and fixing the bugs at the early stage of the SDLC process
– Assures to reduce the cost as bugs are resolved at the earliest
– Helps the developers to improve the design by allowing refactoring of the code
– Assures in simplifying the debugging process
– With the proper unit testing practice, components that are integrated after the build can assure in achieving a quality product
Why Unit Testing is important to perform?
unit-testing helps the development teams to understand the code base, validate the correctness of the developed code, reuse the code, and make the changes faster in the code.
With a proper unit testing practice in place, the developers and testers can help to save time as bugs can be identified early in the process as it is the initial phase of testing. And, skipping or limiting the practice of unit testing can adversely increase the defects and it becomes complex to fix them at a later stage. Hence, it is essential to practice unit testing at the initial stage of the software testing process before planning for the integration testing.
What is the process of Unit Testing?
– The developers write the code in the application for testing the function and would wait for the application to get deployed for removing the test code
– The code is then isolated by the developers to validate the dependencies between the code and other units. This way of isolating the code helps in identifying and eliminating the dependencies.
– Developers significantly make use of Unit test frameworks or unit testing tools for developing automated test cases.
– While executing the test cases, the unit test frameworks help to flag and report the failed test cases. Also, based on the failures in the test cases, the unit test frameworks help to stop the related testing.