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Are Unit Tests a Wasteful Expenditure or a Promising Investment?


9 min read

I’m Dmytro, a seasoned .NET Team Lead immersed in the IT industry for over 6 years. Having been involved in crafting numerous products, I’ve learned that while we often focus on the major aspects of product development, this endeavor has an indispensable yet overlooked side. The booming market entry and continuous business growth hinges on two fundamental elements: stability and predictability.

Whether you’re a business owner or steering a promising startup, a myriad of thoughts and questions pop up:

  • What features suit the product best?
  • What’s the potential for profit upon product launch?

But equally important are questions like:

  • How can coding errors be minimized?
  • What’s the smoothest way to alter the code?
  • How can development costs and bug fix expenses be reduced?

Throughout my experience, I’ve learned that amidst these inquiries, the bedrock solution for optimal product development lies in unit tests. It’s the code validation process that ensures top-tier performance and scalability.

In this article, we will find out what unit testing is, how to write unit tests that resonate with project development and the post-launch stage, and why it’s essential for you as a leader to understand what is hiding behind the beautiful screen of your product.

What is a Unit Test?

What is a unit test, you ask? It’s a way to check and fix the code while it’s being developed. Instead of waiting to test the final product through quality assurance (QA), developers check each part (unit) as they write the code.

This method is designed to catch and fix bugs early during the software development process. It saves the headache of finding small errors just as the product is about to launch.

During performing unit tests, developers spot an error, fix it, and sometimes find more hidden bugs due to the code changes made.

The reason for implementing such a way of testing is pretty logical. It’s cheaper and quicker to fix mistakes as they come up during coding than after the QA team finds them in the “finished product.” Trying to fix code written several months back often causes confusion and chaos in developers’ minds, takes a lot of time, and leads to higher costs and delays in launching the product for you, the person who leads the process.

Why are Unit Tests Important for Your Business? ​

Understanding how a particular process improves overall product development can be challenging. To clarify this, I’ve compiled a list of reasons illustrating why unit tests are essential for creating a functional product and saving money in the long run.

Product Quality

  • Fewer defects. By identifying and rectifying errors in the code at the early stages, your product becomes more stable for end users. My direct experience implementing this testing method on our DashDevs projects showcased remarkable results. The more we test and fix hidden bugs, the quicker product launches, and our clients experience enhanced satisfaction.

For instance, I vividly remember a project where we integrated unit tests and successfully launched the product within six months, precisely on deadline. But another case involved a client who approached us after launching the product by another agency.

They needed to enhance existing features and address app functionality issues. We dedicated approximately 4 months to combing through the previous code, identifying bugs, and making improvements before introducing new features.

Comparatively, the client for whom we created the app from scratch and conducted unit tests during the development phase had a much smoother launch.

Today, at the maintenance stage, we can effortlessly handle issues for our product or implement new features within 3-4 days. This streamlined process allows us to bypass the extensive, time-consuming phases of code understanding and re-testing, which helps our clients save their money and time.

  • Product integrity and maintainability. Unit tests serve as more than bug detectors. They offer a comprehensive understanding of each function and line of code crafted by developers. This deep understanding leads to a well-structured and reliable final product, thereby fostering a solid foundation for future development and ensuring that each release meets the high standards expected by both the development team and the end-users.

Cost and Time Savings

  • Early error detection. Spotting and resolving errors during coding saves costs compared to post-launch corrections.
  • Reduced maintenance costs. A stable product demands fewer resources for support and unplanned fixes, reducing long-term expenses.
  • Faster problem-solving. Well-tested products encounter fewer issues post-launch, resulting in shorter resolution times for production problems.
Discover how DashDevs leverages unit testing to boost your software's reliability and performance

Business Agility

  • Confident changes. Unit tests empower teams to adjust without fear of breaking essential product functions. When developers test their written code, they ensure each element functions correctly.
  • Adapting to market changes. Testing simplifies adapting to meet changing market needs. This flexibility means your users will immediately get improvements or updates. Your product continues working smoothly, ensuring you don’t lose money due to disruptions.

Bill Gates about unit tests.

How to Develop Effective Unit Tests?

Ongoing updates and maintenance are crucial for effective unit tests. As the product evolves with the addition of new features and alterations to existing functionalities, the tests need regular updates.

These updates are necessary to reflect the changes and align with the product’s evolving requirements. Neglecting consistent updates at each stage might render the tests ineffective, which leads to mistakes and reduced ability to identify issues or bugs.

​Unit tests serve a unique purpose in the coding process, distinct from solving end-user issues. Instead, they address problems within your program. Your developers should consider themselves users during unit testing, evaluating each part to meet their expectations. 

The following guidelines serve as a framework to comprehend the crucial aspects of effective unit testing. From my experience in programming and team management, I’ve collected these guidelines to outline the essentials for effective unit testing. 

By using these practices, you’ll notice improved results. As a team leader or business owner, these tips offer a clear way to check if your developers follow best practices and find areas for team improvement. They also provide great insights into creating accurate unit tests for your products.

#1. Craft Clear and Simplified Tests

Write tests that are easy to understand, enabling you to identify why a test failed quickly. Utilize the Arrange, Act, Assert (AAA) structure that allows you to arrange, perform actions, and validate the outcomes.

#2. Create Consistent and Predictable Tests

Your tests should consistently present the same behavior as long as the source code remains unchanged. This approach ensures your tests are independent of other scenarios, preventing instability and unreliable test cases.

#3. Focus on Single Scenarios per Test

Isolate specific scenarios within your unit tests, making it easier to identify and address issues if a test fails. Covering multiple scenarios within a single test can complicate issue identification when the unit test code fails.

#4. Automate Testing Procedures

Automate your unit testing process regularly to monitor changes, track performance, and gather metrics for better team collaboration.

#5. Develop Self-Contained Tests

Create tests that are isolated to specific components using test doubles. This approach leads to faster and more stable unit testing by focusing on one logic at a time.

#6. Avoid Reliance Between Tests

Prevent test scenarios from being interdependent. This helps maintain individual and independent test methods, ensuring tests aren’t reliant on each other.

#7. Limit Active API Calls

Specific functions might rely on external system communication or services during software testing, often called Application Programming Interfaces (APIs). While testing software, minimize direct connections to external systems, like APIs.

Instead, simulate expected behaviors and responses, enabling tests to focus solely on examining individual software components without engaging with external systems. This ensures a more precise evaluation of each part’s functionality in isolation.

#8. Combine Unit and Integration Testing

Balance unit and integration testing to achieve extensive coverage while minimizing testing costs. Base your testing strategy on the testing pyramid model, utilizing automated unit tests and other tests sparingly for overall API or application assessment.

#9. Ensure Repeatability and Scalability

Develop tests in conjunction with application code to maintain a synchronized approach. Reviews during code development provide insights to improve tests, extending testing beyond planned changes to bug fixes.

#10. Test for Security Issues

Embed security testing within unit tests using tools like Bright, a Dynamic Application Security Testing (DAST) scanner, for identifying vulnerabilities in every component or function.

Unit Testing vs. Integration Testing: An Overview

Unit Testing

Unit testing is similar to scrutinizing the unique segments or units of an application. It’s a technique that validates each part separately to confirm its accurate functioning. 

This practice is vital for swiftly detecting and addressing issues within individual elements of the product, ensuring their optimal performance. It’s comparable to examining the inner workings of a watch to ensure every gear functions seamlessly.

Integration Testing

Integration testing revolves around evaluating how different product components integrate and operate together. This form of testing uncovers issues arising from the collaboration of these parts. Much like simulating the synchronized operation of various interlinked components in a machine, it ensures smooth coordination. 

This test method provides a seamless process between diverse elements, such as databases and integrations.

Unit TestingIntegration Testing
Unit testing verifies the correct operation of isolated parts.Integration testing assesses the interaction among different product components.
It facilitates prompt resolution of specific issues within these isolated parts, ensuring their functionality.It pinpoints potential problems arising from interactions between various elements.

Does the Product Truly Need Unit Tests?

As indicated before, the process of implementing a unit test:

  • involves an initial time investment, however…
  • ultimately saves time during the developmental phase.

The value proposition between the time assigned to write the unit test and the time saved during testing depends on your project’s specifics.

There are some indicators that signal the need for unit tests in your project:

  • foreseeable project growth
  • complex features and functionality
  • fixing bugs can be too expensive within your project
  • the critical importance of sticking to project deadlines

If your project aligns with any of these criteria, implementing unit tests becomes advantageous. The more of the points mentioned above apply to your business, the greater the benefit from unit testing.

How unit test can help: graph with potential bugs count per feature

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Potential Risks and Limitations of Unit Testing for Business

While unit testing offers significant benefits, it’s crucial to recognize the potential hurdles and limitations that may arise when implementing this testing framework approach.

#1. Initial Setup Costs

Integrating unit testing into the development process demands an initial investment in time, resources, and tools. Establishing the testing environment, creating test cases, and incorporating testing frameworks can be labor-intensive and may necessitate additional finances. 

Although this initial phase requires dedication, the long-term gains often outweigh the initial expenditure.

#2. Limitations in Testing Scope

Relying solely on unit tests may present a restricted perspective on comprehensive testing. While these tests focus on individual components, they might only encompass part of the spectrum of potential scenarios or interactions within the product. 

Depending exclusively on unit testing might skip crucial issues arising from interactions between various elements, potentially impacting the overall functionality of the product.

#3. Sustained Test Maintenance

Ongoing updates and maintenance are crucial for effective unit tests. As the product evolves with the addition of new features and alterations to existing functionalities, the tests should be regularly updated to reflect these changes and align with the product’s evolving requirements. 

Neglecting consistent updates at each stage might render the tests ineffective, leading to mistakes and reduced ability to identify issues or bugs.


For businesses, investing in unit testing is a crucial step to improve product quality, cut costs, and build customer trust. However, it’s essential to begin and maintain this process correctly.

In my experience, especially with fast-paced startup environments, developing prototypes often leads to neglecting unit and integration tests. Startups frequently focus on rapid product launches, which can limit the time available for comprehensive testing. 

To manage this, a good strategy would be to initially prioritize testing the most critical system parts with unit tests. As your project advances, you can gradually broaden the scope of your testing to cover more areas.

Though setting up unit tests may take more time initially, in the long run, they save time and money. They help catch and fix issues early, reducing the effort spent on ongoing product maintenance.

Looking to implement solid unit testing strategies for your business? Get in touch with DashDevs’ experienced experts to explore how to create unit tests to enhance your product’s quality and ensure long-term success.

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