Functional Testing

Functional testing is a software testing technique that focuses on verifying that a software application's functions work as intended. It ensures that the application's features, user interfaces, APIs, and integrations perform correctly, meeting the specified requirements.

Functional requirements are essential features of the product without which the system won’t work. Non-functional requirements specify how the system should perform the functions, that is, they are the product characteristics that make it easy to use and ensure a better user experience. Even if these requirements aren’t met, the system will still work.

BlazeMeter supports a variety of testing features, including:

  • Scripted and Scriptless Testing — BlazeMeter supports both scripted and scriptless testing approaches. With scripted testing, users can leverage popular scripting languages such as JMeter, Gatling, and Selenium to create custom test scenarios. On the other hand, the scriptless testing option enables testers and non-technical stakeholders to design tests through an intuitive graphical interface, streamlining the testing process.

  • Cross-Browser Testing — BlazeMeter enables testers to validate the functionality of their web applications across different browsers and versions. This ensures a consistent user experience and helps identify any browser-specific issues that may impact the application's performance.

  • Parallel Execution — Efficient testing is crucial for timely releases. BlazeMeter's functional testing capabilities support parallel execution, allowing multiple test scenarios to run simultaneously. This accelerates the testing process and provides rapid feedback to development teams.

  • Comprehensive Reporting — Detailed and actionable insights are essential for effective testing. BlazeMeter provides comprehensive reports that highlight key performance indicators, identify bottlenecks, and offer insights into the application's functional behavior. These reports help you make informed decisions that can enhance application performance.

  • Integration with Continuous Integration (CI) Tools — Seamless integration with popular CI tools such as Jenkins, Bamboo, and TeamCity enables teams to incorporate functional testing into their CI/CD pipelines. This ensures that every code change is thoroughly tested, promoting early detection and resolution of issues.

Functional Testing Types

In the realm of functional testing, various testing types cater to diverse use cases, each tailored for specific scenarios. This section delves into some of the prevalent testing types, providing insights into their application.

The following are sample use cases for functional testing types:

  • Testing login features — Verification of login functionalities against valid and invalid inputs to ensure seamless operation.

  • Transaction processing system — Assessment of the payment gateway's functionality within a transaction processing system, including user notification in case of a failed attempt.

  • File uploading feature — Testing the file uploading feature to ensure it appropriately sends an error message if the file size exceeds the limit.

Unit Testing

A fundamental functional testing type that involves the individual testing of software/source code components to validate their correct functioning. While primarily conducted by developers, Quality Assurance (QA) engineers may also perform unit tests, which are often automated.

When to Run: Strategically employ unit testing in the initial development phases to promptly identify and address bugs. Ideally, unit tests should run concurrently with development, focusing on bug resolution rather than a complex workflow at the project's conclusion. While there's no rigid rule for deciding when to use unit tests, consider using them during the initial development of new features.

Smoke Testing

Commonly referred to as build verification testing, smoke testing determines the stability of a deployed build. If the build proves stable, the QA team proceeds with subsequent testing types, thereby identifying issues in the early stages and conserving time and effort.

When to Run: Conduct smoke tests when new features are introduced to the build. Successful passage of these tests allows the testing process to proceed seamlessly.

Regression Testing

Regression testing, another pivotal functional testing type, verifies that changes introduced in the code do not adversely impact other parts of the product. Various regression testing techniques are employed:

  • Retest All — Execution of all tests multiple times to ensure a bug-free system. This method, though effective, is less commonly used due to its time and resource-intensive nature.

  • Regression Test Selection — Choosing of a subset of tests based on the module where changes are made.

  • Regression Test Prioritization — Identification and prioritization of primary and secondary features, optimizing testing resources.

When to Run: Perform regression tests when development is frozen, and new improvements or changes are introduced in the code.

Sanity Testing

As a subset of regression testing, sanity testing follows proposed code fixes to ensure smooth performance. Quick and documentation-free, it verifies that the fixes align with the expected product behavior, triggering a new build upon success.

When to Run: Execute sanity tests after regression testing and minor code changes, preceding the build's entry into production.

Integration Testing

Integration testing involves testing all software components collectively after integration, employing black-box testing. Common approaches include the following:

  • Big Bang Integration Testing — Conducted after development is frozen when the entire system is assembled.

  • Top-Down Integration Testing — Integrating and testing two or more modules from top to bottom.

  • Bottom-Up Integration Testing — The opposite of top-down integration testing.

  • Incremental Integration Testing — Testing logically connected modules individually.

  • Hybrid Integration Testing — A combination of top-down and bottom-up approaches, focusing on interface and communication testing between modules.

When to Run: Consider performing integration testing after unit testing to ensure a smooth overall process before proceeding with other testing techniques.