Unit testing can be tricky, but it’s essential to get it right!

It is the practice of running your program on a computer, ensuring each piece of code works as expected. Unit tests are often small programs that test one specific thing, such as an if/else statement. Because these tests focus on one particular thing, they’re usually much easier to write and read than full-fledged programs.

In this blog post, we’ll give you some tips on knowing when unit testing should be done and how to get started

What is Unit Testing?

Unit testing is a form of software testing services that focuses on the smallest pieces of code within your program. It’s a way to ensure that each part of your application works as designed and that any errors in the code are caught early on before it’s too late.

Why and When is Unit Testing required?

Unit testing is important for a variety of reasons. It helps identify bugs in your code before they are released to the public, and it can also help you improve your coding skills by learning how to test your code.

Unit tests can be run on any software project at any time, often helping developers determine what needs to be fixed before it gets released. For example, if there’s an error in one of our websites’ code and we’re about to release it to the public, we’ll write an automated test to ensure there aren’t any other errors in our codebase. If we find a bug without unit tests (which is possible), we’ll fix those bugs first before releasing the site.

It helps us catch problems in our code before they become serious problems for our users or company. This means that when things go wrong during development, they can be fixed quickly and efficiently—but only if unit tests are written first.

Read More: Agile-Friendly Test Automation Framework

How does Unit Testing work?

Unit Testing works by using a test runner to execute code in a controlled environment. The test runner will then verify that the tested code works as expected.

A test runner is a tool that runs tests on your project, and it’s usually integrated with an IDE or editor of your choice. This allows you to run your tests without manually compiling and running your program, which can be time-consuming and error-prone.

You have written a function to multiply two numbers:

Int multiply (int x, int y)

{ return x*y; }

The above function takes two numbers as input and returns their multiplication.

A unit test code would look something like this:

Void Test_multiply()

{ assertEquals(multiply(10, 20), 200); }

Unit Testing Best Practices

1. Write a Simple and readable test Case:
   A simple and readable test case name shows the intent of the test case. To understand the test cases, follow consistent naming conventions and only use shorthand. Writing, maintaining, and understanding a simple test case is more accessible. If the test case is complex and you need to change some code, the test cases might break.
2. Cover no of Scenarios:
   Do not write the test cases only for the happy path. At the time of writing test cases, you should be considered all possible scenarios. For example, you should write test cases for error handling and negative scenarios.
3. Write Deterministic Test

   A deterministic test case means showing identical behaviour as long as the code remains unchanged. The goal is to have consistent behaviour for tests to verify and validate the desired function.

   A deterministic test case enables you to understand the issue and fix it. Hence test case should be deterministic. They do not rely on other test cases or external dependencies.

4. Arrange-Act-Assert(AAA):

   This AAA approach helps us to break the process into three stages. It improves your test’s readability by giving it a logical flow.

   1. Arrange: This stage helps to arrange the setup and initialization part of the test.
   2. Action: Perform action on the given test case.
   3. Assert: Assert or verify the outcome of the given test case.

   The following code demonstrates the AAA structure:

   Void Test_Multiply() :

   Arrange:

   int a=10;
   int b=20;

   Act :

   int ans=a*b;

   Assert :

   assertEquals(ans,200);

5. One Use case Per test:
   Each test case should focus on a single-use case and verify and validate the output is as expected for that test method. This will help you get a clear line of sight into the root problem if the test fails.
6. Avoid Redundancy:
   To improve efficiency, you have to write code so that it should not create redundancy. In short, avoid duplicate code. In testing, this practice helps to avoid redundancy by creating a single representation of any component of the application.
7. Automate:
   In manual testing, we manually execute the test cases and maintain the result in files. This manual testing is a very time-consuming and expensive process. So go with the automation testing with the help of the unit testing framework. Some of the most popular frameworks are JUnit for Java and Jest for Javascript-based frameworks like Node-Js. Continuous integration(CI/CD) is also helpful for better practice.

Conclusion

Unit testing is helpful for efficient code, fewer bugs, and a robust framework. A deterministic approach describing their function with easy access and running tests through the AAA approach as often as possible are the keys to successful unit testing. By validating your code as you write it, unit testing is invaluable in ensuring that your developed application is robust and contains minimal bugs.