Negative testing is the process of software testing in which software has to go through possible negative test cases. These test cases can be related to Negative workflow or negative security testing. Talking about negative workflow, negative test cases are the cases that most probably will not be followed by the end-user of the software. Negative testing validates the software with invalid data. It determines the software’s capability to prevent negative flow and react as expected.
Negative testing determines the stability of the software under different conditions. It shows that software works only how it is supposed to work. The software will not entertain any other workflow that is not valid for the particular software.
A few Techniques are used for negative testing, and negative test cases depend on the type of software used. It can differ according to the type of software, but below are some common things used for negative testing.
Negative Testing Software Scenario & Techniques
There are many types of testing worldwide, each with its own purpose. Some are more commonly used than others, but each is necessary to ensure that your product functions correctly. However, some testing techniques may not be necessary at all. Here’s a quick look at negative testing techniques.
1. Injecting invalid data into URL (URL Testing)
- Testing URL of any applications. It includes security; for example, SQL injections can be taken as negative testing of a particular URL.
- Other examples of URL testing. URL https://www.google.co.in is the basic URL for Google search. But putting invalid characters between URLs and checking their behavior includes negative testing. For example, hitting the URL as https://www.goo$%gle.co.in/ should not display the Google page.
2. Not entering proper data into the input field and continue
- The basic requirement of doing negative testing on input fields is that it should accept proper data.
- Suppose the application allows wrong data to be entered into the input field. It leads to the wrong data collection, which can be harmful when using that data in corporate.
- In the first negative testing example, if input fields only allow integers, they should be tested by entering any string char, too. That should prevent the user from entering any string char instead of an integer. See the below screenshot.
- The second negative testing example is for the input field; for example, we see subscribe input fields in many websites where we input email to get news later. It should only accept email format. If it’s taking a format that is not email, it should prevent the user from processing further. See below screenshot
3. Verify database type test in UI as well as the database
- While working on the database testing, database fields must only accept the value set to its table structure. It should not allow other types of value.
- If the column is set with the date and time data type, it should only accept the date and time apart from that value, which should throw an error into a console. That needs to be validated by database schema design. So, that would be a negative test case for the database testing. The same thing should be tested on the UI part as well,
4. Testing size possibility of any input field or any column of the database
- Testing possible size means testing the input field’s length. If one field, a text field, has a length of 500 chars, then negative testing would be entering more than 500 chars and testing that field.
- It will validate the size of the text field and the UI part so that the UI can prevent users from updating this kind of negative flow.
- Another good example of Negative testing on an input field. Any password input field minimum expects 6 chars to be entered. It should not accept less than 6 chars. That would be negative testing of the field.
5. Verify date format possibilities
- Negative testing of a date is necessary to prevent wrong and faulty data from being entered into the database and UI.
- Example of negative testing on date format. For example date, input field allows only MM/dd/yyyy format. Then, we must enter all possible date formats to test the validation and check how the software behaves in the different conditions.
Session-based negative testing
- A session is a time span in which it will decide user validation on a user account. Some decide the time span of an ideal situation should be logged out automatically. So after some time of being an idea, if a user tries to attend to change anything in their account, it shouldn’t let them do that. It will validate the session timeout.
- So, a negative test case will be the same. Keep the idea time span satisfied, and then try to change anything in the user account. It must prevent the user from changing anything into a user account.
- Also, it needs to be confirmed that it should time out at the time the developer has given. It should not time out before and after the exact time. That is a priority negative test case.
Importance of negative testing from the company’s perspective
- Negative testing secures the product on a security basis. It prevents software from being vulnerable to hackers or any entity.
- Negative testing makes sure that the product is secured and will not be a failure with any negative workflows.
- Testing all negative desired workflow of the software will ensure the good health of the software that reflects positively on the organization’s report. The software organization’s first and foremost priority is to deliver quality and bug-free software to the client.
- There is no doubt that positive cases are mandatory, and software must work on all positive workflows. However, negative testing is more critical because any negative workflow failure can lead to the product’s fatal failure, which can cause huge financial and trust issues with the client.
Importance of negative testing from the client’s perspective
- The client always has high expectations for zero bugs to ensure that negative test cases are handled. If any function breaks, it can be taken care of and resolved. However, a client will take any security issue seriously and may give a bad impression.
- The risk level of any negative workflow may differ with the domain of the product. Let’s say any stock market product will take any digit negative testing very seriously compared to any social domain product.
- While creating a negative test case and giving information to the client, it sometimes becomes necessary to categorize negative bug flows and priority for the same.
How to create negative test cases, and what are the things to keep in mind while creating negative test cases for any product?
- The first and foremost thing that needs to be considered is identifying the risk factor for any product and boundary value analysis.
- The important thing is to think about all possible negative test cases that can be possible with the product. In this way, the product can fail. All the flows need to be included in the report.
- We need to cover all the prior cases of the workflows, which are high in risk, and the product’s main functionality.
- Cases also include medium-risk and low-risk bugs; however, the whole software must be validated with the testing.
Advantages of the Negative testing.
- The software will be tested 360 degrees.
- Software security will get much stronger, with fewer chances of software failure.
- Negative testing will make the client trust more and more confident in any software release.
- Negative testing becomes very positive and profitable when the product is related to finance or intelligence-related.
Disadvantages of the negative testing.
- Sometimes, it increases workload and unnecessary testing.
- Sometimes it is too time-consuming.
- We need to have a resource who is experienced in a particular domain.
How does it occur in an industry, and how does the workflow go?
- Whenever any product comes to the testing phase, the tester will plan all the possible functional test cases, and the test plan will be executed.
- Then, according to the size of the product, a team of testers, according to the module, will be assigned to create negative workflows.
- Again, the priority of negative test cases changes according to the product domain.
- Once all the negative tests have been executed, the product gets released if any priority bug is found, and then it goes again for the bug correction.
- Some companies give more importance to negative test cases if that product contains more confidential information. But again, it differs according to the product domain.
- Keep in mind that functional testing is the most important for any product. Negative testing must be included in the test case and strategy to ensure the security, quality, stability, and strength of the software.
- Hence, negative testing often increases some testing load but reduces risk factors—some domains like finance and other risk factor-containing applications.
- It will validate all the data that is getting inserted into fields. It includes valid data and invalid data, too.