Teste de Software: os 7 princípios de teste | CTFL - Aula 5

Summary

In this video, Mauro introduces the seven essential software testing principles from the ISTQB CTFL syllabus. He covers key concepts such as the importance of testing to detect defects, the impracticality of exhaustive testing, and how early testing can save time and money. The video also delves into the idea that defects tend to cluster in specific areas of software, the need for constantly updating tests to avoid the Pesticide Paradox, and the necessity of context in testing. Finally, it emphasizes that the absence of errors does not guarantee success, as user satisfaction and software functionality play key roles in a system's effectiveness.

Takeaways

• 😀 Software testing principles are general guidelines aimed at improving testing efficiency.
• 😀 Testing cannot guarantee the absence of defects, only the presence of them. Testing aims to identify problems before users encounter them.
• 😀 Exhaustive testing is impossible due to the vast number of potential combinations to test, particularly in complex systems like e-commerce platforms.
• 😀 Prioritize testing critical areas and components, as most defects are often concentrated in a small portion of the code.
• 😀 Early testing saves time and money by identifying defects early in the software development process when fewer elements need to be tested.
• 😀 The pesticide paradox explains that repeating the same tests may not uncover new defects, necessitating regular updates to testing strategies.
• 😀 Software testing depends on the context. Different types of software (e.g., social media apps vs. AAA games) require different testing approaches.
• 😀 Defects tend to cluster in certain areas of the software, such as complex components, third-party dependencies, or new features.
• 😀 The absence of errors is an illusion; software can still fail even if defects are absent. Usability and meeting user needs are crucial.
• 😀 Initial tests in software development help catch issues early and prevent costly delays later in the process.
• 😀 The goal of testing is to ensure the software meets user expectations, functions properly, and is reliable and safe, even though exhaustive testing is not possible.

Q & A

What are the principles of software testing?

The principles of software testing are general guidelines that help ensure effective testing. They are often seen as a reference, like a compass, and evolved over time to the seven principles found in the CTFL syllabus by ISTQB. These principles aim to improve testing efficiency and optimize the use of time.

Why does testing show the presence of defects and not their absence?

Testing helps discover problems before they reach users. However, finding no defects during testing doesn't mean the software is defect-free. It simply means that no defects were found during the tests conducted, and there may still be defects remaining in the software.

What does the principle 'Exhaustive testing is impossible' mean?

Exhaustive testing means testing every possible combination of inputs and scenarios. This is often impractical, especially for complex systems. It is better to focus testing efforts on the most critical areas of the software, based on risk evaluation and the functionality most used by users.

How does early testing save time and money?

Early testing helps identify and correct defects in the initial stages of development. Since the number of elements to be tested is smaller and simpler at the start, it's easier and quicker to fix issues, saving time and reducing costs compared to later-stage testing.

What is the 'Defects Cluster' principle?

The principle that defects tend to cluster means that a small number of software components are often responsible for most of the defects. Testing should prioritize these components, such as complex modules or areas with frequent changes, as they are more likely to contain defects.

How does the 'Pesticide Paradox' relate to software testing?

The Pesticide Paradox, derived from the resistance of pests to a pesticide over time, means that if the same tests are repeatedly used without change, their effectiveness decreases. To avoid this, tests should be regularly updated with new cases and data to continue discovering new defects.

Why is context important in software testing?

The testing approach must consider the context of the software being tested. Different types of software, like a social media app versus a AAA game, will require different testing strategies due to their unique objectives, platforms, and target audiences.

What does the principle 'Absence of errors is an illusion' mean?

Finding and fixing defects does not guarantee the software's success. A system might be technically correct but still fail to meet user needs, especially in terms of usability. Even if defects are low, there might still be unaddressed issues, making the software ineffective or difficult to use.

What role does usability testing play in software development?

Usability testing ensures that the software meets user expectations and is user-friendly. Even if the software is technically correct, poor usability can lead to user frustration, making the software less valuable or even useless.

Why is it necessary to update test cases during the software testing process?

As software evolves, test cases need to be updated to account for new features, changes in the system, or previously undetected issues. This ensures that tests remain relevant and effective in detecting new defects.