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Functional Testing: What Is It, Tools and Best Practices

Functional Testing: What Is It, Tools and Best Practices

Functional testing plays a crucial role in attracting and retaining customers. By testing the functionality of your ecommerce, you ensure it meets user expectations and achieves your business objectives. But what does it consist of? What tools and processes do you need to achieve success with it?

In this guide, we explore the concept of functional testing as it relates to ecommerce. We also discuss the various types of functional testing, how it’s performed, and examine the best practices and tools available in the market. Whether you’re a seasoned QA professional or new to the world of testing, we hope to provide valuable insights to help you optimize your ecommerce platform and deliver a seamless user experience.


What is Functional Testing?

Let’s first answer the most basic question. Functional testing is a type of software testing that assesses whether a system’s functionalities meet specified requirements by validating its input, output, and behavior. If we translate that into ecommerce terms, it means verifying that each component of your ecommerce ecosystem functions as intended. 

Unlike other forms of testing that assess non-functional attributes such as performance or security, functional testing specifically evaluates whether the system behaves according to the specified functional requirements. We can treat this testing as black box testing – it is focused on functionality and not concerned about your ecommerce application’s internal workings, i.e. source code.

At its core, functional testing is focused on meeting intended business needs. It evaluates user interactions and an ecommerce system’s response to various scenarios and conditions. Functional testing validates everything from user interfaces and APIs to client/serve communication.

Types of Functional Testing

Here are the common types of functional testing to consider, with examples of how they would apply to ecommerce:

Unit Testing

Unit testing involves testing individual components or units of an application in isolation to ensure they meet the specified requirements. Developers typically write scripts to test each unit and validate them against predefined criteria.

Smoke Testing

After a release is deployed on an ecommerce platform, smoke testing is performed to ensure its overall stability and identify any critical issues. For instance, a smoke test might verify that users can access the homepage, browse products, add items to their cart, and proceed to checkout without encountering any errors. This quick and preliminary test helps ensure that the basic functionalities of the ecommerce platform are working as expected.

Regression Testing

Regression testing ensures that changes to the codebase do not negatively impact existing functions or introduce new defects. For example, if a new feature is added to an online store’s checkout process, regression testing would verify that it does not disrupt the functionality of other components, such as product search or account registration.

Integration Testing

Integration testing validates the interactions between different modules or components of a system to ensure they work seamlessly together. For example, integration testing might verify that the product catalog module of an ecommerce store communicates effectively with the inventory management system, ensuring that product availability is accurately reflected.

Usability Testing

Usability testing is a method of testing the functionality of a website, app, or other digital product by observing real users as they attempt to complete tasks on it. For example, they may evaluate the ease of navigation, the clarity of product descriptions, and the efficiency of the checkout process.

API Testing

API testing involves validating the functionality and performance of the application programming interfaces (APIs) that connect various systems and services within the ecommerce ecosystem. To learn more about API Testing and its automation, read this article.

How is Functional Testing performed?

Functional testing typically follows a series of steps to ensure thorough testing coverage:

  1. Identify the functionalities: This first step involves identifying the key functionalities of the online store that needs to be tested, based on business requirements. Common features to test are product search, product browsing, adding items to cart, checkout process, payment processing, order tracking, and account management.
  2. Create test cases and input data: Test cases are scenarios intended to simulate real-world user interactions with the ecommerce platform. For example, a test case may consist of a user searching for a specific product, adding it to their cart, proceeding to checkout, and completing the purchase. Another important step here is to determine the desired user input values – which product, what search query, etc.
  3. Execute the test cases: Test cases are executed based on the predefined test scenarios and test data. This involves performing actions such as navigating through the website, entering input data and interacting with UI elements. Test cases are executed manually or using automated testing tools, depending on the complexity and scope of testing.
  4. Compare actual vs expected results: After executing test cases, the actual results are compared against the expected outcomes to identify any discrepancies or defects. For example, if a user encounters an error in the calculation of shipping costs during the checkout process, it is noted down as a functional defect that needs to be addressed.
  5. Reporting and tracking defects: Any defects or issues identified during functional testing are documented, reported, and tracked using a defect tracking system. This allows developers and QA teams to prioritize and address the defects efficiently.

By following these steps, ecommerce businesses can effectively perform functional testing to verify the functionality and performance of their online stores, so that it behaves as expected and meets business requirements.

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What is a Functional Testing example in ecommerce?

Now that we’ve covered the essential steps of functional testing, let’s look at a specific test case example and requirements that you may expect for it.

Test case scenario:

An ecommerce site that allows users to search for products, add them to their cart, and proceed to checkout.


  • The search functionality should return relevant results based on user queries.
  • Users should be able to add products to their cart and view the updated cart total.
  • The checkout process should allow users to enter their payment and shipping information and complete the purchase.

It is possible to have more detailed specifications / expected outcomes, nevertheless this is just an example.

What to look for in a Functional Testing tool

An important component of the functional test execution process is the choice of tool. While it is entirely possible to execute tests manually, more often than not it is the most practical method. Hence, finding the right functional testing tool for your ecommerce is essential not just for the efficient use of your test resources, but also for its consistency and accuracy in execution.

Here are some key factors to consider when choosing a functional testing tool for your ecommerce business:

Ease of use: The functional testing tool should be user-friendly and accessible to all members of the QA team, including testers with varying levels of technical expertise. Most no-code test solutions are well designed for functional testing. In particular, Valido AI’s intuitive test creation and monitoring features can streamline the testing process and enhance cross-team collaboration.

Cross-platform compatibility: Ecommerce websites are accessed from various devices and platforms, including desktop computers, smartphones, and tablets. Therefore, the testing tool should support cross-platform testing to ensure compatibility across different operating systems, browsers, and devices.

Support for Ecommerce-Specific Features: Look for a testing tool that offers features specifically designed for testing ecommerce functionalities. This may include support for testing different screen resolutions, user actions (mouse hovers, keyboard input), and everything else that you would find in a typical ecommerce user journey. The key is that the tool should be able to simulate real-world ecommerce transactions.

Automation Capabilities: Automated testing can significantly reduce the time and effort required for functional testing, especially for repetitive tasks and regression testing. Choose a testing tool that offers automation capabilities, such as intelligent test management and scheduling automated test runs.

Adaptability to UI changes: Ecommerce websites are frequently updated with new features, design changes, and bug fixes. This has a significant impact on the reliability of visual testing. The testing tool should be able to adapt to changes in the user interface (UI) without requiring extensive rework of test configurations. Look for features such as ignore annotations and dynamic element identification.

Real-time monitoring and reporting: Effective monitoring and reporting capabilities are essential for tracking test results, identifying issues, and obtaining actionable insights. The testing tool should provide real-time visibility into test execution and defect status, allowing for better tracking and resolution.

Scalability and Flexibility: As ecommerce businesses grow and evolve, their testing requirements may change. Choose a testing tool that can scale with your business needs and accommodate future expansion. The tool should be flexible enough to support a wide range of testing scenarios, from small-scale functional testing to large-scale performance testing.

Best Practices in Functional Testing for ecommerce

As you can see, there are a number of different ways of performing functional testing. We’ve compiled essential best practices in order to ensure the effectiveness and efficiency of functional testing for your ecommerce.

Select the right test cases 

When planning functional testing for an ecommerce website, prioritize test cases that cover critical functionalities and user workflows. Focus on testing scenarios that are essential for the shopping experience, such as product search, adding items to cart, checkout process, and payment processing. Additionally, consider scenarios that are prone to errors or have a significant impact on user satisfaction.

Implement data-driven tests

Ecommerce websites often handle large volumes of data, including product information, user profiles, and transaction records. Implement data-driven testing techniques to generate diverse test data sets and simulate real-world usage scenarios. This approach helps identify potential data-related issues and ensures thorough testing coverage across different data conditions.

Focus on end-to-end testing 

Ecommerce transactions involve multiple steps, from product browsing to order fulfillment. Conduct end-to-end testing to validate the entire shopping journey, including product discovery, selection, checkout, and post-purchase interactions. Don’t overlook scenarios such as applying discounts or promotions, adding items to favourites, and receiving order confirmation emails.

Monitor UI changes and updates 

Ecommerce websites frequently undergo UI changes, updates, and enhancements to improve user experience and functionality. Regularly monitor UI changes and updates to ensure that existing functional tests remain relevant and effective. Update tests as needed to accommodate UI changes and verify that core functionalities remain intact across different iterations of the website.

Cross-team collaboration 

Effective collaboration between QA teams, developers, designers, product managers and even digital marketing teams is essential for successful functional testing in ecommerce. Foster open communication, share test plans and results, and collaborate on identifying and resolving issues promptly. Align testing efforts with business goals and user expectations to deliver a high-quality shopping experience that meets customer needs and preferences.

Wrapping Things Up

Functional testing is a critical aspect of ensuring the quality and reliability of ecommerce websites and applications. By understanding the fundamentals of functional testing, exploring the various types and methods, and adopting the right tool and best practices, ecommerce businesses can get the most out of their testing efforts.

At Valido AI, we specialize in intelligent test automation, UX audit, and monitoring solutions tailored to meet the unique needs of ecommerce businesses. Our tool empowers businesses to rapidly identify critical UX issues affecting performance, and utilize AI-powered insights to optimize their conversions.

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