What is Unit Testing?
As the saying goes, it is easy to break when alone. In software testing, the same logic is applied through unit testing. The modules are taken one at a time and the errors are specified. The errors and anomalies are thus more visible when seen alone rather than in a group If in software development and testing, each unit is tested individually then it is known as unit testing. The aim of this work is to confirm that every bit of the program runs the way it should. When the codes are being formulated the unit testing is also conducted by the developers. Every part of the code is viewed separately to check its efficiency. This said unit can be anything like a function or a procedure or a module or a method depending on the scenario.
Usually, unit testing is done first before moving onto integration testing. Unit testing falls under the category of white-box testing. Even though it should be done by developers, sometimes due to lack of time it might be executed by the Quality Assurance team too. If unit testing is not done properly then the system has to shed more money while doing other testing like Integration Testing and Beta Testing. Therefore if unit testing is done properly then it not only saves time but also saves on a lot of cash.
With the help of unit testing bugs that may be prevalent are fixed. If there are changes to be made, the developer can quickly execute them. It also helps in reusing the code. The code and the tests can be fed in the project and are run.
Popular Unit Testing Frameworks
Unit Testing for C#
NUnit
Nunit falls under xUnit is a type of unit testing. XUnit is basically a collection of a number of unit testing frameworks. Nunit can be used for .NET files. Originally Nunit was ported from JUnit and the recent version is 3. This version has been designed in a new way to offer new features.
Unit Testing for Java
JUnit
JUnit is a type of unit testing used for Java that follows the concept of testing first and then coding. It is an open-source testing framework. The data is first tested as stated above and then put in the code. It gives an easy way of writing code.
TestNG
TestNG is used for Java Programming. It is similar to JUnit except there are some more functionalities that make it easier than JUnit and stronger.TestNG is capable of concurrent testing. It is an open-source framework that can do annotations too. The execution model used by TestNG is an important aspect of it too.
Unit Testing Framework for C and C++
Embunit
It is used for C and C++ languages. This unit testing tool can be used by both testers and developers. It is an open-source testing framework where source code used in the tests is automatically formed.
Unit Testing Framework for JavaScript
HtmlUnit is used for JavaScript. It is an open-source testing framework. Different GUI features like links, tables, forms can be obtained by it. The GUI-less browser in the Java library that is offered by HtmlUnit is used for Java Programs.
Unit Testing Best Practices
The best practices for Unit testing are:
- yUnit tests should be easy to read and understand.
- The aim should be that the unit test can only fail if the code is broken and not any other scenario. Thus the unit test must be trustworthy.
- Unit tests should verify and validate only a single use-case. This makes the tests easy and more understandable. It is also recommended to use as few assertions as possible.
- The Unit Tests should not be dependent and should be able to run on any machine.
- The Unit tests should follow an automated process and the results should be accessible and reviewed all in the team.
Advantages and Disadvantages of Unit Testing
Advantages
- It helps in building confidence about changing or in maintenance of code.
- The codes are less dependent on each other because of unit testing therefore if changes take place the impact on the overall code is less.
- With the use of unit testing the codes become more reusable.
- If a bug is found while doing unit testing the cost of fixing it is lesser compared to when found in other levels.
- The process of debugging is comparatively easier.
Disadvantages
- Writing a good unit test is time-consuming and difficult.
- Because of the above reason the tester or the software developer can make errors putting the whole system in jeopardy.
- Sometimes errors cannot be found. This is because in unit testing the modules are tested away from each other and then clubbed.
- Integration and system errors might go unnoticed.
FAQ
Unit testing is used to check how correct a particular code is. The unit part of the function or code in the application is tested in the process.
The different types of unit testing are:
1. Black Box Testing
2. White Box Testing
3. Gray Box Testing
The different unit testing tools are:
– NUnit
– JUnit
– TestNG
– Mockito
– PHPUnit
In the coding phase or development phase, unit testing is usually conducted. The tests are done by separating a part of the code and running the tests on it. This separated part may be a method or an object or a module depending on the situation.