What Is Negative Testing And How To Do It?
The software testing process is a vital part of the software development life cycle because it allows the testing of your website or app. There are multiple kinds of tests that you can conduct if you work in the software development industry.
Still, all the types of testing can be divided into two groups: positive and negative testing. Both categories have equal importance, but positive testing is more widely used than negative testing.
In this article, we are going to have a more detailed look at what negative testing is, how it works, and its pros and cons. We will help you learn more about the differences between positive and negative testing. Let’s get started!
What is negative testing?
Negative testing is a type of software testing aimed to check websites or apps for unexpected information inputs and conditions. Such unexpected information or conditions can be caused by different things varying from mistaken data type to powerful malware attacks. Negative testing aims to prevent the software product from failing caused of negative inputs and enhance its quality and responsivity.
Differences between negative and positive testing
Apart from negative testing, positive testing is a testing type that helps make sure that the software product is functioning properly under ordinary circumstances. On the other hand, negative testing focuses on performance under unpredictable conditions. Besides, positive testing takes into account only the input of correct data while negative testing also allows the input of incorrect data.
How to perform negative testing: different techniques
These are the techniques that can be used for performing negative testing:
Boundary Value Analysis
This technique implies writing the test cases for values that are not included in boundary limits.
Equivalence Partitioning
This technique aims at testing the functionality of a software program. It is performed by grouping the input values into different partitions. You will test some values in each partition.
Error Guessing
This method highlights the certain conditions that trigger failure or error messages. If possible, you need to define and fix the issue without crashing the entire product. However, in certain cases, a wrong result may result in a rapid “downstream” failure if the error condition is not detected and handled right away.
Check Listing
It doesn’t belong to common techniques, but this is still an important approach that records error conditions that you are going to test. This technique is commonly used along with error guessing.
Anti-patterns
If there exist design patterns, anti-patterns are their right opposite. If design techniques are the most suitable way to solve a problem, the anti-pattern is a non-working solution, it is a perfect source to perform negative testing.
Exploratory Testing
This negative testing technique is used for increasing your understanding of the product while the test is in progress. It can be performed at the same time as other tests. Exploratory testing can demonstrate to you a more extensive picture of which elements in your product are working and what do not work.
Negative Testing Scenarios
The aim of tests negative is to highlight possible weaknesses under various circumstances. These are possible unexpected situations where errors may take place:
- Populating Required Fields
- Correspondence Between Information and Field Types
- Allowed Information Bounds and Limits
- Permitted Number of Characters
- Web Session Testing
- Reasonable Data
Advantages of Negative Testing
Here are the key benefits of negative testing as a type of software testing:
Negative Tests Help Define Inaccurate Bug Processing
It enables avoiding application failures provoked by incorrect bug processing. It also helps confirm if the code is no longer managing a programmed use case. It can also avert situations where the customer cannot access information that is required for bug fixing.
Helps Define Possible Weaknesses in Security
Negative testing lets you make sure that a client can’t enter a personal account in the program if the organization (software product owner) doesn’t give permission. It allows stopping a group of users from utilizing specialized features of the system if necessary.
Helps Keep Your Database Clean
The database will be in fine condition if it only contains valid information. Negative testing can raise the possibility that only valid data is kept and displayed by the program.
Why Testers Avoid Doing Negative Testing
Apart from the substantial benefits of negative testing, positive testing remains a more preferred type by software testers. To have a better understanding of why it is happening, let’s have a closer look at the disadvantages of this testing method.
In certain cases, negative testing turns into a waste of time and energy. In many cases, there is no necessity to perform excessive negative testing. This testing type requires qualified and experienced testers to create negative test cases. From the client’s perspective, negative testing is another process that delays release and adds cost.
Negative Test Cases Examples
Let’s step away from all that tech stuff and explain how negative testing works. For instance, let’s take a rollercoaster. This is a popular activity for kids and their parents. Everybody knows how it works and what experience people have. If we applied negative test cases to a rollercoaster, we would ask the following and many other questions while performing negative cases:
- What would happen if the weight of the people exceeded the allowed one?
- What would happen if the power goes off during a ride?
- What would happen if people try to drink water during a ride?
Key Takeaways on Negative Testing
Negative testing is a core method of software testing, but it can easily turn into a time-consuming and demanding process that only distracts your team. With its pros and cons, it is crucial but not necessary in all cases.