Negative Testing in Software Testing: A Complete Guide by QASource

QASource Engineering Team
QASource Engineering Team | October 27, 2023

A Complete Guide to Negative Testing in Software Testing

Software testing is vital because it allows you to test if an application is working properly. There are various types of tests that you can perform if you work in the software industry.

Nevertheless, all these tests fall under one of these two classifications: positive and negative testing. Both categories are equally important, but positive testing is more popular than negative testing.

Find out what is negative testing is in software testing. Learn why testers usually avoid performing negative tests in this blog. Discover how to implement it and what testing scenarios you can expect. Understand what the difference is between positive and negative testing. Finally, explore the benefits of it in the following sections.

What Is Negative Testing?

Software testing is the process of checking if the basic functions of your software program work correctly according to its design. At the same time, it verifies if the application is equipped to handle challenging situations and invalid inputs.

It refers to a negative approach to software testing. It is also called failure testing or error-based testing. It aims to spot the negative characteristics of the application by designing test cases. It reveals how the program responds to invalid data. It allows you to compare the expected output against the incorrect output.

 

Why Do Testers Avoid Performing Negative Testing?

Despite its usefulness, it seems to have a negative reputation among software testers. Many professionals are hesitant to perform it because they believe it may unnecessarily cause a delay in the launch of the software product.

Some testers consider it a distraction that wastes time and resources. They are convinced it is better to pour their efforts into positive testing instead.

The lack of skills and knowledge also hinders testers from employing it. Not everyone understands completely how the software works and what its limitations are.

However, despite its name, it leads to positive results. It should be an essential part of your software testing strategy for the following reasons:

  • Organizational Responsibility

    Your company is responsible for offering excellent software products to its clients. Negative testing, in tandem with positive testing, is necessary to ensure the stability of your application. You may not be able to guarantee that your program is entirely free from errors, but you must at least do your best to minimize failures through this testing.

  • Client Satisfaction

    Your clients have entrusted software projects to your company because they believe you can create excellent software products. High-quality software is especially important if it is related to online stocks, e-commerce, and other sensitive business matters.

    It is crucial if you aim to attain client satisfaction. Still, it is up to your clients to decide if they will invest in the extra expenses necessary for negative testing.

 

How To Perform Negative Testing in Practice

These are some smart techniques you can utilize to perform negative testing on software applications:

  • Boundary Value Analysis

    This method involves writing the test cases for values outside the boundary limits. For instance, your boundary limits are 1 to 100 in case you are testing a text field that accepts data within the 1 to 100 character range.

  • Equivalence Partitioning

    It is a technique that tests the functionality of a software program. It entails grouping the input values into various partitions. You will be testing some values in every partition.

  • Error Guessing

    This procedure pinpoints the specific conditions that trigger failure or error messages. If possible, you should try to identify and correct the issue without a system crash. In some cases, though, an incorrect result may lead to an extreme “downstream” failure if the error condition is not immediately noticed and addressed.

  • Checklists

    It is a basic but crucial method that documents the error conditions you plan to test. A software testing checklist is commonly used in tandem with error guessing.

  • Anti-patterns

    If there are design patterns, anti-patterns are their antithesis. If the former is the best way of resolving an issue, the latter is a solution that does not work. Anti-patterns are the ideal source of negative tests.

  • Exploratory Testing

    This technique increases your knowledge about the application while the test is ongoing. It may be conducted simultaneously with other tests. Exploratory testing can give you a clear picture of which aspects of the application work and what don't.

  • Small Scale Test Automation

    It is a method that uncovers memory errors, code defects, and other issues that are occasionally revealed in production use. It entails performing the same action thousands of times to see its effect on the program.

  • Fuzz Testing

    This procedure involves the input of random data, which may cause unexpected failures, crashes, and issues. In this case, there are no preset expected results, unlike other negative test cases. It is simply an observation of what may potentially occur because of arbitrary inputs.

  • State Transition Testing

    It is a technique that is utilized to spot defects in the application. It originates from the concept that software can only exist in one particular state simultaneously. For instance, a program is considered to be in its normal state until an issue reveals itself.

 

Negative Testing Scenarios

The purpose of it is to pinpoint possible application failures in different circumstances. Here are some potential situations where errors and crashes may unexpectedly occur:

  • Populating Required Fields

    Certain software and web pages showcase fields that must be filled up by the user. You can design a test that leaves the required fields blank so you can evaluate the program’s response to this scenario.

  • Correspondence Between Data and Field Types

    Most digital forms and dialog boxes are capable of receiving data in a certain form, such as text, number, date and time. You can make a test where the wrong data type is entered into a control to see how the application reacts in this case.

  • Allowed Data Bounds and Limits

    Some software programs include input fields that only receive data that falls under a particular range of numbers or text. You may design a test that inputs a value lower or higher than the boundaries of a particular field.

  • Allowed Number of Characters

    There are web pages and applications with fields that only permit a limited number of characters to be entered by the user. You have the option of conceptualizing a test where more characters are entered in the field than is normally allowed.

  • Web Session Testing

    Certain web browsers require users to log in before loading web pages. You can prepare a test that attempts to open web pages in the application without logging in beforehand.

  • Reasonable Data

    Some programs and web pages feature fields with a reasonable limit. You can make a negative test that inputs invalid data into the field.

  • Interrupt Testing

    In the case of mobile app testing, simultaneous interruptions, for example, incoming calls, messaging, low battery and network loss to check how the app handles these interruptions.

  • User Interface Testing

    By providing invalid inputs to generate the error intentionally, we can check whether the error messages are correctly displayed and whether user-friendly information is displayed.

 

Difference Between Positive and Negative Testing

In contrast to negative testing, positive testing is a type of software testing that ensures that the application is working properly under normal circumstances. This table gives you an overview of the main differences between the two:

Positive Testing Negative Testing

It presupposes that the software application will be used under standard conditions.

It considers the possibility that the software application may be used in challenging circumstances.

It assumes that the program will not encounter issues under ordinary circumstances.

It is open to the likelihood that you could encounter errors in less than ideal situations.

It is taken for granted that only valid data will be entered by the user.

It considers the probability that invalid data may be inputted by the user.

 

Benefits of Negative Testing in Software Testing

Positive testing has its advantages, but negative testing also has crucial benefits. These are just some of the perks of negative testing software applications:

  • Identify Incorrect Bug Processing

    It allows you to avoid application failures caused by faulty bug processing. It helps confirm whether the software code stopped managing a programmed use case. It can also prevent situations where the client cannot access the data necessary for bug fixing.

  • Identify Possible Weak Spots in Security

    Negative testing in software testing allows you to ensure that a client cannot access a personal account in the program in case they are not permitted to do so by the organization. It enables you to prevent a group of users from using specialized functions of the application if necessary.

  • Maintain a Clean Database

    The database of a program will be in good condition if it only includes valid data. It can increase the possibility that only valid information is stored and displayed by the application.

  • Enhanced system Robustness and Resilience

    System exposure to various failure conditions helps refine the error handling mechanism and improve the quality, which helps achieve the enhanced robustness and resilience of the system.

 

How Artificial Intelligence (AI) Helps in Performing Negative Testing?

Artificial Intelligence (AI) is revolutionizing the field of software testing, including negative testing, by automating and enhancing the process. AI is transforming the landscape of negative testing in software quality assurance by automating, enhancing and accelerating the process. These advancements help identify potential issues and vulnerabilities in software applications, ultimately leading to more robust and reliable systems.

  • Invalid Input Testing

    AI can automatically generate test cases with invalid inputs, such as entering letters in a numerical field, to ensure the software handles these situations without crashing.

  • Security Testing

    AI tools can simulate common security attacks like SQL injection, cross-site scripting (XSS) and cross-site request forgery (CSRF) to check how the software responds to potential threats.

  • Performance Testing

    AI can stress-test a system by generating a high volume of user requests to see how the application behaves under load and identify performance bottlenecks.

  • Negative UI Testing

    With the help of AI can simulate negative user interactions, like clicking multiple buttons at once or trying to perform actions that are not allowed, to check for unintended behavior.

  • Root Cause Analysis

    AI-powered tools can help identify the root causes of negative testing failures. By analyzing logs, system behavior, and error messages, AI can pinpoint the exact source of the problem. This information is invaluable for developers to fix issues promptly. For example, in a social media application, AI can help trace the source of login failures or data corruption errors.

 

Conclusion

Negative testing is a key element of software testing, but it can be a time-consuming and expensive process. You have the option of partnering with QASource to save time and resources. Our outstanding QA outsourcing services are the ideal solution to your software testing needs. Let our expert team of engineers handle your negative testing projects for the best results.

Disclaimer

This publication is for informational purposes only, and nothing contained in it should be considered legal advice. We expressly disclaim any warranty or responsibility for damages arising out of this information and encourage you to consult with legal counsel regarding your specific needs. We do not undertake any duty to update previously posted materials.