What is Unit Testing? Importance & Best Practices

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8 min read

Gone are the times when quantity was prioritized over quality. In today’s times, it is believed that it is not important to develop 10 different mobile apps, and come up with one solution but to make sure it turns out to be the best possible one in such a way that people are more likely to trust you for the long haul. Now in the world of software development, quality comes at paramount and to ensure it, developers emphasize a lot on testing. Today, software testing is pretty much in tandem with the development procedure. Once considered as an afterthought is now given prime importance. Speaking of which, the following post focuses on what unit testing is, how it is important in today’s times and what are the best practices to conduct unit testing.

Introducing Unit Testing

As the name implies, unit testing is about testing one unit - a small piece of code that can be isolated in a system. This is a software development process where testing is done for small chunks to ensure proper operation. Unit testing can be conducted and completed during the development process.

Now unit testing is done to isolate the written code to test and determine whether it is working as previously thought or not. Also, unit testing has the potential to detect early flaws in code which can be quite difficult to find out in the later stages.

  • To isolate a small section of code

  • To check if the code is correct or not

  • To test every function and procedure

  • To fix bugs or identify them at a very early stage

  • Save unnecessary expenses

  • Ensure quick changes

  • Offer code reuse

Technically speaking unit testing is one of the main components of Test-driven development (TDD) where a product is developed by continuously testing and revising. Unit testing is highly considered as the first method for software testing and is performed before integration testing. Does it rely on external code or functions, absolutely not! Software development teams should perform again and again, be it manually or automatically.

Sounds quite amazing but what does it look like? Well, a unit can be anything you want to be. A line of code or a method, or a class the smaller the better. Here you are bound to have a more grandeur view of exactly how the code is performing.

For example,

def divider (a, b)

return a/b

end

And when conducting small tests it may seem something like this

class smallTest < MiniTest::Unit::testCase

def tiny_test

@a=9

@b=3

assert_equal(3, divider(a, b))

end

end

Quite a simple example right? But how do you realize what I mean by the term small? Now a unit test comprises three stages

  • Planning

  • Writing Test Cases

  • Performing the unit test

The final step is where developers and quality analysts come together to review the unit test and pass it on for the later testing stages. So basically it’s all about validating that each small unit or part of the software is working significantly as per pre-determined needs and requirements.

  • Unit testing is a software technique where different units such as programming modules, different usages or procedures, basically any and every kind of operating procedure just to make sure that things are fine or well suitable for each other or not leading to the development of amazing software.

  • The testing method is highly preferable where there is a need for testing every independent module. So what happens here is, it can be determined whether the issue is with the developer or not.

  • It is much related to the functional correctness of independent modules

  • Unit testing is always carried out during the development of the application

  • In SDLC or V Model, this one is the first level of testing followed by others such as integration, regression, system, etc.

Types of Unit Testing

  1. Manual Testing

The first and foremost type of unit testing is manual testing. This is a technique where all the features and functionalities are tested seamlessly. As the name suggests, with the help of a set of predefined test cases, here the tester tests software applications. Finally, the final report is submitted. Manual testing mostly is time-consuming since it is done by humans. Also, the chances of human errors are extremely high.

Now you must be wondering why there is a need for manual testing. Well, since the ultimate software will be used by humans so it would be great if humans test the product as they will be using in the same way as their end users. Moreover, human testers can be flexible with their approach, they can successfully change according to changing conditions.

  1. Automation Testing

The next type of unit testing is automation testing. Automated testing is said when it is possible to check and test a software product automatically. To save time and money several software development companies emphasize conducting automation testing right from the beginning. Moreover, automation tasks can run at any point of the day, all thanks to the scripted sequences. The ultimate objective here is to reduce the number of test cases that require to be executed manually. Now this doesn’t mean, it thoroughly eliminates the scope of manual testing.

  • Seamless quality assurance

  • Error-free or bug-free software

  • No human intervention

  • Increased test coverage

  • Testing can be done as many times as you want

Top Unit Testing Techniques

  • Black box Testing

  • White Box Testing

  • Gray Box Testing

Top Unit Testing Tools

  • Jtest

  • Junit

  • NUnit

  • EMMA

  • PHPUnit

Importance of Unit Testing

When you can scrutinize even the most minor parts of the application, then it is said to be a successful completion of unit testing. so that things can work out flawlessly. Further, I would like to mention certain points that emphasize the importance of unit testing.

  • Early detection of issues

The first benefit of conducting unit testing is early detection of the issue. Imagine you have spent days and nights developing software and in the end you get to know that the app crashes as soon as the user plans to check out, how will you feel? Pretty devastated right? Well, with unit testing this will no longer be an issue. Here developers as well as testers will spot defects and issues accurately right from the beginning so that they don’t become more difficult to fix.

  • Enhanced code quality

The next advantage is to enhance the code quality. Unit testing ensures each unit of code works as pre-determined and in the end, you come up with software that is bug-free and highly reliable.

  • Increased confidence

Unit testing can boost the efficiency and productivity of software developers to a great extent. You see when the code is being tested again and again, developers can easily gain confidence in their work and be more and more productive ensuring high-end quality-based software.

  • Quick development

The next benefit is faster development. Unit testing ensures developers work seamlessly as they keep on validating changes in the code without waiting for the entire system to be tested.

  • Better Documentation

The next benefit to take into account is better documentation. Unit testing offers clear and concise documentation of the code. It would be simply great if you can mention, how it behaves. Since everything is documented precisely, software development teams can easily collaborate and work wonders. Also, they are on the same page.

  • Reduced time and costs

The next benefit of unit testing is reduced time and costs. Yes, since unit testing mainly emphasizes automation, the time taken to conduct one and the price required is pretty low.

Best Practices for Unit Testing

  1. Writing proper test names

The first and foremost step to succeed is to write reliable unit tests. To be more precise, choose a proper test name. This might seem quite basic to you but it is extremely important. When you give a good test name, the readability of the code automatically gets improved for programmers as well as other software professionals who will work on that specific code in the future.

  1. Speed up with isolation

The next step is to speed up with isolation. Unit tests must be carried out well in isolation. This means there must be no dependency on other tests and or interference of any external dependencies. Faster code coverage is only achievable when there is the use of simpler and independent modules. And not to mention automation can be the cherry on the cake. All these measures can surely speed up the test activity and also, ensure unit testing is more appealing for developers.

  1. Addressing a single use-case

The next step is to test a single use case and not an entire chunk. Make sure to test a single block of code. So when it’s done, better insights can be derived especially regarding the errors, where they are exactly derived from.

  1. Aim for maximum test coverage

The next step is to aim for maximum test coverage. Yes, whether you are a tester or a developer, you must aim for maximum test coverage. So in other words, test it as much as possible.

  1. Mandate Automation and Consistency

Unit testing is one such concept where the scope of automation is pretty wide and important. Although it is equally important to conduct unit tests manually, testing via automation isn’t just cost-effective but pretty efficient. Above all, nothing can beat its scope to save an adequate amount of time.

In addition to automation, having some consistency is equally important. You see unit tests aren’t supposed to be performed one time but they must have consistency. It is supposed to be an ongoing process. And do you know what is the best part here? The code is seamlessly maintainable.

Final Words

And we are done here! I hope the post matches up to its title. In all, unit testing is quite important especially when you want to conduct a modern application that is highly robust, scalable, and worth considering for your end users. So this is where technology can be a pure bliss instead of the worst nightmare. This is it! I hope you come up with the finest mobile application for your end users. Good luck and keep watching the space for more information and updates.