How and Why Unit Testing is Getting Popular?
Unit Testing has moved from fringe to mainstream, which is great. It’s taken quite a while around the idea that unit testing is a necessity for most of today’s projects. Unit testing is the ultimate in assessing functionality of each unit while the application is being built. This helps prevent future errors by identifying and developing end-to-end test scenarios, ensuring the correctness of functionality as per business requirements.
Testing the final version of product or website can give errors that are difficult to solve.Therefore the best approach is to divide the software in elements
with different units and test them from the smallest to the biggest. Unit test allows developers to make big changes to code quickly. Most unit tests are written using some sort of test framework, a set of library code designed to make writing and running tests easier. But all you need is to choose the right tool that is specific to your platform and script based tools. Most popular JS test tools used by developers include:
qUnit - It is the oldest and it’s seen popular use in jQuery. Lots of support across the board, from Q&A to CI server support. It lacks fluent syntax and configuration
is complex. Makes 3rd party libraries relatively difficult.
Jasmine - It’s built to be easy to set up and use in almost any scenario. It has nice fluent syntax for assertions built-in, and does play pretty well with other assertion libraries. Supported by many CI servers. Asynchronous testing can be a bit of a headache. Expects a specific suffix to all test files (*spec.js by default).
Mocha - Built specifically for testing nodeJs modules. Its API is similar to that of Jasmine’s, with a bit of syntactic sugar added to make it more conductive to a wider range of scenarios, such as BDD. It has its own test runner baked in, so that’s a concern you should never have to worry about.
It also, unlike Jasmine, has really nice support for testing asynchronous methods. Allows use of any assertion library that will throw exceptions on failure. Supported by some CI servers and plugins.
Advantages:
Early detection and resolution of problem: Developers test individual units and resolve the problems without any impact of any other code. Through Unit testing, problems can be detected and resolved in early stage and save valuable time in entire software development life cycle.
Debugging Process: Unit testing makes debugging process very simple as only the latest changes made in the unit needs to be debugged in case of a test failure. Simplified Integration: Unit testing is advised to be used in bottom up testing method as it generally reduces the uncertainty within the unit itself, hence makes the integration easier.
Easy maintenance and changing of code: As independent and smallest units are tested, impacts of changes of other units/codes are less. Once the tests are completed, and bugs are fixed, same units can be reused.
Reusability of Codes: Codes need to be developed in modular form to perform unit testing. Modular codes are easier to reuse both for the same as well as any other projects.
Faster Development: Unit testing allows faster code development to the developer as they can write as well as test the code of their own instead of depending on “Developer’s test”. It helps to fix the bugs early.
Increases Confidence: Unit testing helps to increase developers confidence in terms of changing as well as maintaining code. Good unit tests are capable to catch all the errors that are caused because of the change in codes and help to fix it faster.
Disadvantages:
Time consuming: It can make the development of any application a long process because testing each unit takes time.
Thorough documentation: It requires thorough documentation. If the developer does not meet the criteria, then unit testing is going to be a waste of time. Many developers and programmers tend to rush and are impatient and this is a common reason why unit testing is never done and many applications never become productive.
Conclusion: Unit testing is a good approach to keep code maintainable, understandable, debuggable, and bug-free. Good unit tests make it possible to improve the production code. One can confidently refactor the system until the code is good. Direct benefits like cost, time and effort contributes most for the reasons behind the gaining popularity of unit test which is the leading trend in current software industry.