Why Should You Use Unit Testing in Software Development

Why Should You Use Unit Testing in Software Development

Software testing is one of the essential parts of the software development process. Unit testing is the modular method to test programs to see if they function according to the specs. It checks the individual modules for any errors and ensures the components are working as intended.

What is the Unit Testing Process?

It comprises 4 main blocks:
1. Test case creation
2. Review
3. Baseline
4. Test case Execution

A test case should be made independently and be modular so that it can be modified easily. It protects the developers and provides high fidelity feedback on a high-level functionality as it is decoupled from the implementation. When more complex features are added to the software, we will spend a huge effort to make changes to the old design. Therefore, if we can just use a small piece of modular code without touching a number of components, it saves us a lot of time to test its functionality. It is fairly manageable for unit testing. Imagine if we were making a change on a large application suite, when something hits the fan, you have to sift through tens or hundreds of testing just to understand if the issue is a true positive or a false positive.

Unit testing can improve the quality of code. Developers can identify the tiny bugs present in the units before they go into production or go for integration testing. With that, all kinds of bugs can be resolved at an early stage and no other part of the software blocks will be affected. It reduces the downtime and the costs of debugging effectively.

Besides, building a unit test allows the developer to actually think through the design of the software and what needed to be done before they start developing the code. It helps them to stay focused and create a much better design.

Example of Unit Tests

Here's the example of a unit test we can build - we create a mock object to test sections of the code. Do note that the method should be prefixed with test* in order to perform code testing.

You can also use the setUpClass and tearDownClass property to execute before and after the tests in a given class respectively. The tests could be multiple, but the setUp and tearDown can be repetitive and used to execute many tests. Hence the testing framework for setUp and tearDown will be automatically called for every single test run.

If the setUp raises an exception, we can tell immediately that the framework has failed and the test method will not be executed. Also, we can provide the tearDown to tidy up the framework after the test method is finished.

If you are developing the microservice using python's flask, you want to build a unit test to check the connection has been established successfully.

Closing Thought

Building an appropriate scope for unit tests while minimizing the number of components to validate the scope can provide huge benefits in terms of bug reduction and refactoring effort.

To summarise what we have learnt, having unit testing is great because it:

  • has a simple design and is decoupled from the implementation.
  • reduces the amount of time needed to restructure for A/B testing
  • is easier to find software bugs at an early stage
  • simplifies the debugging process

Thank you for reading!

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