Introduction
The main objectives of software testing are to check and validate that the software product works as intended and to enhance the software’s quality. The two major types of software testing are functional and non-functional testing. Positive and negative testing go under functional testing.
These testing approaches have their main features and functionalities and play a significant role in testing the software product. This article will cover the basics and explore the differences between the two while offering examples.
First of all, to test any application, we need to provide input values to validate if the results are based on the given requirements or not.
In positive and negative testing, the following elements must be considered:
- Input data
- An action that needs to be performed
- Output data
What is positive testing?
Let’s start by talking about positive testing. Essentially, positive testing is about confirming that the system works as expected when given valid input. It’s the “happy path” of testing, ensuring that everything functions correctly when users do things they’re supposed to do. This is crucial for demonstrating that your software meets all the intended requirements.
For example, if you’re testing an online banking app, positive testing would involve checking that a user can log in with the correct username and password, transfer money between accounts, or view their account balance without any issues. In positive testing, you’re verifying that the software behaves as it should when everything is in place.
What is negative testing?
On the other hand, negative testing is designed to ensure that the system behaves correctly even when it’s subjected to invalid input or unexpected conditions. It’s all about testing how well your software handles “bad” data. For example, what happens if a user tries to log in with an incorrect password, enters too many characters in a text field, or tries to transfer more money than their account balance?
The goal of negative testing is to uncover vulnerabilities, crashes, or unexpected behavior when things go wrong. It’s critical to ensure that your software can gracefully handle errors and return useful feedback to users, without causing major issues or crashes.
Boundary Value Analysis
It is a software testing methodology where test cases are designed with boundary values in a range.
Example: A system can accept numeric values ranging from 0 to 10. All other digits are invalid values. The boundary values -1,0,1 and 9,10,11 will be tested using this methodology.
Equivalence Partitioning
This software testing methodology divides input data into multiple partitions. Each partition’s values must be tested at least once. Positive testing uses partitions with valid values. Negative testing is achieved on partitions with invalid values.
Example: The numbers from 0 to 10 can be divided into two or three partitions. We have two divisions in our case: -10 to -1 and 0 to 10. Sample values (5 and -5) may be taken from each situation to test the scenarios.
Why Are Positive and Negative Testing Important?
Both positive testing and negative testing are essential for building robust, reliable software. While positive testing ensures the system meets its basic functionality, negative testing helps safeguard against potential user errors or malicious input that could compromise security or user experience.
By covering both sides, you’re ensuring that your software works as expected in typical scenarios, while also being resilient to potential issues in the real world.
Real-world Impact
Consider an e-commerce platform where a bug allowed users to enter negative values for product quantities, leading to skewed inventory data. A balanced approach of positive and negative testing could’ve prevented this real-life blunder, safeguarding both the user experience and the company’s bottom line.
Limitations to Keep in Mind
Understanding the limitations of positive and negative testing is key to developing a balanced, efficient QA strategy. Here’s what you should watch out for:
Limitations of Positive Testing
- False Sense of Security: Positive testing mainly deals with ‘happy path’ scenarios, meaning it only checks if the program works under ideal conditions. This can provide a deceptive sense of assurance that the software is bug-free.
- Scope Limitation: Positive testing doesn’t cover edge cases or unexpected user behavior. This limitation leaves gaps in your testing strategy where bugs can hide.
- Lack of Robustness: Solely relying on positive tests might result in a product that appears stable under ‘lab conditions’ but breaks when confronted with real-world anomalies.
Limitations of Negative Testing
- Resource Intensive: Negative testing tries to cover all the bases, which requires a substantial investment in time and skilled manpower. Because it’s comprehensive, it can often seem like you’re looking for a needle in a haystack.
- Complexity: Negative testing often involves complex test cases that are difficult to design and maintain. If not well-documented, this complexity can become a hindrance in future test cycles.
- Risk of Overemphasis: It’s easy to go overboard with negative tests, especially when it’s known that the software will be used in highly variable conditions. The downside is that too much focus on negative testing can lead to a negligence of positive scenarios, causing an imbalance in your testing strategy.
- False Positives: When exploring the full range of ‘what could go wrong,’ negative testing could generate false positives that may not represent actual defects but consume resources to investigate.
Differences between positive and negative testing:
| Positive Testing | Negative Testing |
| does not cover all possible cases. | It covers all possible cases. |
| It’s implemented only for expected conditions. | It’s implemented for unexpected conditions. |
| It’s performed on every application. | It’s performed where there are chances of unexpected conditions. |
| Execution time is shorter for positive testing. | Execution time is longer for negative testing. |
| It’s a testing process where the system is validated in contradiction to the valid input data. | It’s a testing process that contains validation in contrast to invalid input data. |
| Inexperienced people can execute it. | Testing professionals can perform it. |
| Positive testing is less significant than negative testing. | Negative testing is more vital than positive testing. |
| It ensures software is standard. | It provides 100% defect-free software. |
conclusion
By implementing both positive testing and negative testing, you’re taking a comprehensive approach to software testing that ensures your system works as expected and can withstand unexpected conditions. These two testing methodologies go hand in hand to make your software more reliable, secure, and user-friendly.
So, as you continue your testing journey, don’t forget the importance of both positive testing and negative testing. Whether you’re building a simple app or a complex system, these techniques will help ensure you’re delivering quality software that meets user expectations and stands up to potential threats.
Stay Updated with the Latest in QA
The world of software testing and quality assurance is ever-evolving. To stay abreast of the latest methodologies, tools, and best practices, bookmark our blog. We’re committed to providing in-depth insights, expert opinions, and trend analysis that can help you refine your software quality processes.
Delve deeper into a range of specialized services we offer, tailored to meet the diverse needs of modern businesses. As well, hear what our clients have to say about us on Clutch!