Unit testing: redundant or essential for a high-quality development

When making the digital product the business owner dreamed to get for a long time, they often wish to control each step of the development life cycle and mostly its time. And in some cases, the non-propper prioritization of some steps can harm everything. 

Let’s discover with this article one question that arises controversy among the teams of developers – unit testing as part of development activities. Do they are really so important for product quality and how to make them with maximum efficiency?

Unit testing as a part of developers responsibilities

Through the entire development life cycle, the product undergoes numerous evaluations and testing procedures. Though, unit testing stands a bit apart from general quality assurance. 

These procedures are performed by the developers with the smallest parts of the code – units. And the developer is the person who defines how big the unit is, which can be a sole function from three lines of code or a small module integrated into the system. Unit testing is performed in isolated sections, such as testing cart flow serviceability. The next step is the integration testing needed to check if all small modules interact as it was intended. 

The paradigm of testing only after making something can be broken here, as some tests can be made even before the initialization of the code production. Such an approach is called test-driven development and requires more resources for requirements definition and evaluation. 

That is why business often chooses the lighter option with simple unit testing and integration testing for their projects. That helps to minimise the number of resources required and get the decent quality of the final product that should not get endless bug lists from quality assurance specialists. 

The most value unit tests get in complicated projects with a big team of developers. When several persons work together, they may not know what others do in a particular moment. Something can go wrong beyond the vision of one and the entire system can be threatened. Testing allows seeing the possible conflicts before they even appear and influence other development sections.

How to understand that the unit test is good

It is rather obvious that the bigger the product, the more modules or functions with complicated logic it has, the more tests should be done. The goal of any unit test is to give confidence that the code does the things you expect it to do. And not every unit test reaches this goal. 

Let’s start testing the simple cart of a random e-commerce website. The developer can create the test checking whether the data is received by the server. Sounds logical for newcomers, as the primary function of any cart is data transferring from user to server and backward. Though in the result, such a test shows nothing and is considered weak. The propper stages of such testing should look like:

• check if data is received;
• check the validity of data;
• check if the order is completed;
• check the correspondence of the data in the order and data received by server;
• check the total sum of the order;
• check availability of the discounts;
• check the status of the order;
• check the dates;
• and dozens of other parameters that can be crucial both for users and businesses.

That is why the developers try to measure the quality of their tests to ensure their maximum effectiveness. Such confidence in the code stability can bring fruits much later when the product is launched to the market and receives updates or new functions. 

There are several approaches to the evaluation, though the most common is the coverage method. It can be found in most dashboards and reports as it has great advantages – you can quickly and without much difficulty calculate the number of blocks that get tested. The bigger number is, the more chances that all lines of the code get their check for serviceability. 

Creation of the map that covers up to 100% of the code (that can be a line, statement or branch) requires the additional involvement of the developer though can bring better results in the overall product quality. It shows that our code does exactly what was planned in all cases. 

To make coverage as big as possible, the developers should consider two points:

1. Project managers and developers should clearly define the requirements for each function of the product. Without preliminary evaluation, it can be impossible to create tests that cover all these moments, something can be missed in the result and cause critical errors. 
2. The calculation of this parameter can not be totally automated. Each particular case requires the personal touch of the developer. They should manually compare the test case and the requirements defined with the first step. At least check if the function does what is expected in each situation.    

These observations arose from the cases when trying to cut some expenses the tests coverage was calculated automatically. Such an approach leads to the situation when with the addition of an extensive functional module, the part of the functions crushes due to a single line of code. The system calculated that it was tested, though the quality of the test itself appeared to be poor and do not show all conflicts in the logic. 

The benefits of unit testing for business

As was mentioned in the definition, unit testing brings confidence that everything works as intended. That can be the main benefit of this approach to the development, but there are several advantages even besides it. 

1. Fast bug finding

The bugs are found from the moment the code is created. The developers can make changes without waiting for the poor code influence or spoil other modules or sections. Finding a floating bug’s reason in huge systems can take up to several weeks. When run locally, tests cut the search area up to a single function.

2. Saving time and money

It is the logical continuation of the previous point. Faster testing leads to less time spent by quality assurance specialists and finding the root reasons. The non-obvious profit is in the fact that the users of the product get it more stable without unexpected annoying bugs that can ruin their trust in your brand. Surely, the business has to invest money and time in performing tests by the developers first, though they will be compensated even before product launch, especially when speaking about website development for startups.

3. Documentation creation simplified

Reliable products need documentation on the code and information architecture. The developers perform the preliminary analysis of the functions before tests performing. This conclusion allows making this documentation with less effort. As the result, the documentation covers most of the possible flows of the product and get easier scalability for the future. 

4. Confidence in product

This point is associated with the code coverage and experience of the developers team. In case if the developers get sufficient resources to perform analysis of the requirements, test the units properly, the better coverage is, the more stability is given to the product. 

5. Better scalability

After analysis and documentation conclusion the developer can find the idea on how to simplify some parts of the code. As the result, the code or even the architecture get some changes that positively impact serviceability. Under the conditions of clear architecture, implementation of the next functional modules becomes an easy thing. Besides stability, the growing products get the aptitude to grow. 

To test or not to test the digital product code

This can not be a question for those who wish to get the product getting appreciation. The advantages from the above show that the proper implementation of the unit testing can bring great fruits for the product. 

The combination of approaches, such as unit testing and integration testing can validate the details that stay hidden if only one approach is used. And to ensure that the revealed bug is fixed, the developers build an additional test. 

Old tests that were performed some time ago should also be checked and renovated. That leads to maintenance of the tests performed by the company. The tests should be revised and updated due to any inner or outer changes related to the product. 

The bigger project is, the more resources should be given for this purpose. Up to 60% of the time needed for the code creation can go to unit testing. But such a sacrifice is necessary for the successful release of the product.

The testing-based approach will save time in money in future and ensure stable work and easier scalability. The reliable environment of the product presence on the market is defined with its quality first of all.  

Wish to get the product tested with the application of all requirements mentioned? Contact us, and we will create a clear estimate for your particular project.