Effective software testing goes beyond confirming that an application functions as expected with valid inputs; it includes both positive and negative testing.
While positive testing ensures the system works correctly with valid inputs, negative testing explores how well the application handles invalid inputs and unexpected scenarios.
Remarkably, a substantial portion of test cases—approximately 85%—usually correspond to just 70% of the overall requirements. This emphasizes the significance of validating positive scenarios. However, the often overlooked 30% dedicated to failed negative value testing is equally crucial. This aspect ensures that the application exhibits robust behavior under unfavorable conditions and unexpected inputs.
This comprehensive approach, covering both positive and negative scenarios, contributes significantly to delivering a dependable and high-quality software product.
Positive testing involves validating an application’s functionality with valid inputs to ensure that it performs as expected. Testers do this by creating test cases based on predetermined outputs with the intention of confirming that the system accepts inputs for typical user use.
This type of testing is crucial and helpful for identifying vulnerabilities and ensuring the system’s resilience against inappropriate data.
For instance, consider a login functionality where a user is required to enter a username and password. In this scenario, positive testing would involve verifying that the system allows access with the correct combination of a valid username and password.
Positive testing not only ensures the system’s expected behavior but also aids in knowledge sharing regarding the system architecture throughout the Software Development Life Cycle (SDLC).Example of Positive Testing
The method is the same as that of negative testing. But here, instead of false data, valid data will be entered, and the expected result is the system accepting the code with no problem.
Specific Benefits
Negative testing explores the system’s behavior when it is subjected to invalid inputs or unexpected conditions.
The objective of negative testing is to ensure that the system responds appropriately by displaying errors when necessary and not exhibiting errors in situations where it should not.
Negative testing is essential for uncovering vulnerabilities and testing scenarios that may not have been explicitly designed.
For instance, consider a scenario where a user is required to enter a password. Negative testing in this context would involve entering invalid inputs, such as passwords with special characters or exceeding the allowed character limit.
The purpose is simple – to test the system’s ability to handle unexpected inputs and scenarios that may arise during real-world usage.
Filling up Required Fields – Imagine that there are fields in the website that require a user to fill it up. Negative testing can be done by feeding the box with negative inputs such as alphabets; either the webpage should show an error message or it should not accept the input.
Factors that need to be considered while performing a negative test
Forget about simply aiming to crash your application. True negative testing is about resilience and smart defense:
The Real-World Impact
Think of users out there – they won’t always be perfect. Negative testing makes sure your software is ready for:
The Bottom Line for Testers
Not doing negative testing is like boxing training without ever sparring. Sure, they know the moves, but a real fight is messy. Negative tests get us ready for the real-world chaos users inevitably create, ensuring a robust, user-friendly experience.
While each type of testing has its own unique characteristics and features, as mentioned below
are some of the key differences between positive and negative testing
Feature | Positive Testing | Negative Testing |
---|---|---|
Scope of Inputs | Focuses on testing a specific number of user inputs with a valid set of values. | Involves testing with excessive (load) inputs and an invalid set of values. |
Perspective | Done with a positive point of view, ensuring that the system accepts valid inputs. | Approached with a negative point of view, testing for scenarios and inputs that are not designed. |
Test Conditions | Identifies a known set of test conditions based on client requirements. | Conducted with an unknown set of test conditions, testing anything not mentioned in client requirements. |
Password Test Example | Validates that the password test scenario accepts 6–20 characters, including alphanumeric values. | Ensures the password test scenario does not exceed 20 characters and does not accept special characters. |
Positive and negative testing are integral components of software testing, collectively working towards achieving a 100% reliable and quality application.
Positive testing ensures that the system performs as expected under normal circumstances, while negative testing explores how the system behaves when subjected to invalid inputs and unanticipated scenarios.
Therefore, it is important for organizations and testers to recognize the significance of both testing methodologies and incorporate them into their testing strategies to deliver bug-free software and enhance overall software quality.
By understanding and implementing positive and negative testing effectively, testers can contribute significantly to the development of robust and resilient software applications.
Writing positive and negative test cases in Selenium involves crafting scenarios that cover expected behaviors (positive) and potential failure scenarios (negative). Here are examples for both:
Test Steps:
Expected Result:
public void testValidLogin() {
// Test steps to open login page, enter valid credentials, and click login
// Assert statements to verify successful login and redirection
}
Test Steps:
Expected Result:
public void testInvalidLogin() {
// Test steps to open login page, enter invalid credentials, and click login
// Assert statements to verify login failure and error message presence
}
In both cases, use assertions (e.g., Assert.assertEquals()
, Assert.assertTrue()
) to validate the expected outcomes. Make sure to handle synchronization issues using appropriate waits to ensure the elements are present or visible before interacting with them.
Remember, negative testing should cover various failure scenarios such as incorrect inputs, missing data, or unexpected behaviors.
Positive Testing
Happy Path Testing
Key Differences
Example
Consider testing a login form:
Positive Testing:
Happy Path Testing:
1. Invalid Data Format
(Source)
2. Boundary Value Testing
3. Entering Invalid Characters
( Source )
4. Mandatory Field Omission
( Source )
5. Incorrect Data Combinations
6. Duplicate Data Entry
( Source )
7. File Upload Errors
( Source )
8. Interrupted Operations
9. Session Expiration
( Source )
10. Excessive Data Input