How to Build Effective Unit Tests?
Unit tests are quick, short and automated tests that are performed to ensure parts of a software program works. The specific functionality of a method or class is tested. Developers can make sure that their code works by writing unit tests before it is passed on to the QA team for further testing. In this article, you will get to know what is unit testing and some key points that help in building effective unit tests.
What is unit testing?
Unit Testing is a testing method where individual components of software are tested. Each unit of the software code is validated in order to ensure whether it is performing as expected.
Following are six key points that need to be considered for building effective unit tests:
1. Understand the need for testing: For a test to be successful, it must be clearly defined in the first place. Testing every aspect of a specific object/scenario is not an issue, but, several such tests are gathered into a single method by the developers. This in turn creates a fragile and complex “unit test.” To avoid such issues, apply the scenario that has been tested and the projected result as a part of the test method name. If naming a test creates a problem for a developer, then there is a lack of focus on tests.
2. Self-contained is a key factor of unit tests: Dependencies should be avoided such as register values, databases or environment settings. A single test should not be determined by running other tests before it. The order of execution of other tests should also not affect the single test. By using global states such as external data (i.e., database, registry), environment settings, static variables may cause “leaks” between tests. Each of the “global states” between test runs must be properly initialized and cleaned.
3. The “deterministic” factor should be applied to tests: A test is considered to be in the worst scenario when it passes some of the time. A test should fail until fixed or should pass all the time. Those unit tests that pass some of the time directly mean not having a test at all.
4. The significance of naming conventions: There should be a need to understand as to why a specific test has failed. A failed test is noticed by its name hence, the test method name becomes important. It will be easy to ascertain what was tested and why it failed when a well-named test fails.
5. Appropriate usage of duplication: A code that is written twice isn’t a good practice. In production code, maintainability issues are triggered, when duplication is done. However, when duplication in tests is avoided, then tests that have been created are difficult to read and understand. Eliminating duplication can be done provided it does not affect the code that is being tested.
6. Strategic application of testing: The success of unit tests is determined based on writing tests that would only fail in case of a requirement change or actual error. Writing fragile unit tests can be avoided by applying a few rules. Due to an internal change in the software, these tests fail and does not affect the user. The code that was written by the same developer usually writes unit tests, because the developer knows how the solution was implemented. The inner workings of how a feature was implemented are difficult not to test.
When testing internal/private methods and objects take place, it gives rise to other issues. These methods are private and there is a reason for that and that is they are not meant to be seen outside of the class.
The above mentioned six points give a brief idea for developing effective unit tests. If you are looking forward to implementing unit testing in your project or want some expert advice on the efficacy of unit tests, then just get connected with one of the leading software testing services company.
About the author: I am a technical content writer focused on writing technology specific articles. Software testing is one of the areas in which I’m really interested.