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What is Unit Testing?

Unit testing is a logical way to test small pieces of code. When you’re developing anything from a desktop software application to a mobile app or web app, you can use unit testing to strengthen and test your code.

What’s Unit Testing?

Source code can be tens of thousands of lines long and can grow into billions of lines of code. Google’s projects, and not just their search engine, spanned some 2 billion lines in 2015. Microsoft Windows is likely under 50 million lines of code.

Unit testing for smaller projects involved logically isolating code from the system in small chunks and testing it.

Modern frameworks and tools for unit testing include:
*Dozens of others

There’s still some debate on when this practice originated, but it’s widely believed that unit testing has been in place in some form from the time computers originated. When you consider a “unit,” you have to consider what a unit consists of before testing.

A unit can be many things, including but not limited to:

*Lines of code

Even a single line of code can be part of a unit test. Running small, bite-sized tests like these allows for rapid testing of code. You can rapidly perform thousands of meaningful tests using unit tests.

When Should You Perform Unit Testing?

Unit testing is a little different from other forms of testing because it’s the developer that will put all of these tests in place.

The developer knows better than anyone which parts of the code would benefit from unit testing. When the developer puts these codes in place, they’ll be able to determine which functions, classes, objects and other items need to be accessed and how they can be accessed.
Adding this form of testing into your code is ideal as the code is being written.

If you’re just adding in testing after the entirety of the code is in place, it’s important to work with the original programmer whenever possible. The coder will be able to identify areas in the code that may have issues much better than someone scanning over the code for the first time.

It’s important to note that unit testing is just one form of testing that can be put in place. Developers are likely to conduct an array of different manual and automated tests and may also work with a security testing company to strengthen their code.

Why Unit Testing is Important

As code continues to expand, it’s important to have checks and balances in place. Testing helps in this area because it enables you to conduct tests for a variety of circumstances:

*TDD, or test-driven development, requires the developer to write code before the production code is in place. The practices will include writing the test code, writing code to satisfy the test and finally refactoring the code for maximum performance. While tedious, a lot of developers opt for TDD because it adds confidence to the code as it’s being written.

*Checking production code is the second most common use of a unit test. The code is written after the production code and checks to make sure that the code is doing what the developer had hoped. Automation can be put in place to test every iteration of code. If issues occur, they’re logged, and the developer is notified so that the issue can be corrected.

Unit testing is important because it can validate coding and determine if any issues exist in the existing code. Since the unit tests are in place, they can quickly be deployed and any new code that’s added that may cause issues can be validated.

Every time there’s new code added to existing source code, there’s a chance that something will conflict or cause unexpected behavior.

The use of unit testing allows for this code to be tested, errors to be logged and fixes to be pushed much faster.

One of the main issues found with testing is that teams need to adopt the practice together. There may be certain team members that aren’t used to writing code for unit tests, so these users must be taught common practices to keep the testing code in place and running optimally.

The goal is to perform smart tests that provide your team with relevant information and data without having to test every object or line of code.

Meta Description: Unit testing is a common part of today’s source code. Learn why developers add unit testing to code and why it’s an important part of the development cycle.