Your Definitive Guide to Unit Testing

Nov 3, 2022

appsurify unit testing best practices

What Is Unit Testing?

Thinking about implementing automated testing but not sure where to start? Look no further than unit testing. 

To better understand unit testing, picture a lightbulb factory. There are many different processes that go into manufacturing these lightbulbs, and a slew of various components.

One day at the factory, a new batch of lightbulbs come off the production line, ready to be packaged and shipped out to stores. A few lightbulbs are pulled for quality assurance, and, to the factory worker’s dismay, they don’t light! Now production must come to a halt, bulbs that have already been shipped must be recalled, and the factory suffers huge losses. To top it off, no one is sure what caused the defect. What a mess. 

Imagine if the factory had a way to quickly and cheaply test individual lightbulb components before the manufacturing was complete. The factory could pinpoint problems at the source and save valuable time and money. This is what unit testing does for an application.

Unit testing is a type of functional test in which small portions of your application code—units—are exercised in isolation from other software components. The objective is to make sure each unit of code acts as expected. When implemented on a large scale, unit testing can help developers run mock scenarios and find bugs faster.

The Role That Unit Testing Plays in Your QA Strategy

As illustrated in the lightbulb example, unit testing can play a vital role in your team’s quality assurance strategy. 

What sets unit testing apart from other types of software testing is its precision. By isolating portions of your code, you can easily verify the code’s functionality. If the unit test fails, you know exactly where the issue lies. 

And because this type of testing is so quick, you can employ lots of unit tests and gain a collection of valuable feedback. This feedback increases development productivity, acts as a security protocol, and can help you deliver a high-quality product to your end-users.

While other tests such as end-to-end testing are valuable in their own regard, they are generally slower, less precise, and more expensive to implement and maintain. Having unit testing in your arsenal of software testing tools is never a bad idea.

Unit Testing Best Practices

Now that you know what unit testing is and what it can do, let’s take a look at some best practices to help get you started:

Keep it simple

Remember, just like your application code, your test code can have bugs as well. One way to circumvent running into issues with your tests is to measure cyclomatic complexity.

Cyclomatic complexity is a software metric used to indicate the complexity of a program by specifying how many execution paths a source code can follow. You want code with lower cyclomatic complexity. The lower the complexity, the easier the code will be to maintain and the less likely it is to experience bugs.

Quickness is key

Depending on the scale of your project, unit tests should take mere milliseconds to run. Generally, hundreds of unit tests are employed on a project, so if you’re being bogged down by lagging tests, you need to simplify your test code. 

In a similar vein, make sure your unit test is quick to write. One of the main reasons for using unit testing is its speed, so if unit tests are taking a long time to develop, consider switching to a different type of software test.

Ensure repeatability

Unit tests should always return the same results if nothing was changed between runs. Of course, tests will return different results based on whether they pass or fail, but if a test that passes on a piece of code then fails on that same piece of code after the same test was implemented, you have a problem. 

You need to ensure your tests are deterministic and trustworthy. Make sure your unit tests are completely isolated and do not rely on any external factors.

Name your tests appropriately

Naming standards are important because, in the end, your unit test names must make sense for you and your team. Naming standards express the intention of your test and are an important factor to consider when developing test code because they also serve as documentation.

Streamline Your Unit Testing with TestBrain

Unit testing is one of the most important automated testing methods that a developer can use. When done correctly, this type of testing can result in faster development times and a better customer experience overall. 

By keeping your test code simple, quick, repeatable, and well named, utilizing unit testing in your software testing suite is sure to be a breeze. 

To streamline your unit testing even further while ensuring flaky failures don’t break your build, tools such as TestBrain can help your development team catch and isolate bugs before it’s too late. Appsurify TestBrain is a risk-based testing tool that enables QA and Developer teams to test faster, find bugs sooner, and accelerate development cycle times. The tool cuts automated test suite execution times by over 90% – accelerating ready results by 10X.

If you’re interested in finding out more about what automated testing tools can do for your unit testing and QA teams, reach out to our team.