A logical test case is a test scenario that defines the conditions to be tested, using logical operators, but without specific implementation-level values for input data or expected results.
Understanding Logical Test Cases
Essentially, a logical test case outlines what to test, not specifically how to test it with concrete data. It focuses on the logic or the condition that must be satisfied for a particular functionality to be considered correct. The actual values and outcomes will be determined in subsequent stages with concrete or physical test cases.
Key Characteristics of a Logical Test Case
- Abstract Data: It uses logical expressions and conditions instead of real input values. Examples include: "a positive number," "an empty string," "a number within a certain range," etc.
- Focus on Logic: The main focus is on the validation of specific paths of the code based on the defined logic, not on specific implementation details.
- No Concrete Results: Expected results are described in general terms (e.g., "should return an error," "should be true," etc.) and not as absolute values.
- Foundation for Concrete Cases: Logical test cases serve as blueprints for creating concrete test cases with implementation-specific input values and expected results.
Examples and Practical Application
Here's a table that demonstrates the difference between a logical test case and its concrete counterparts:
| Aspect | Logical Test Case | Concrete Test Case |
|---|---|---|
| Input Data | "A valid username and password" | Username: "user123", Password: "password456" |
| Expected Result | "User should log in successfully" | Application should display "Welcome, user123!" |
| Logical Condition | Username length greater than 5 characters | Actual string length of the username is greater than 5 |
Practical Insight:
Creating logical test cases is often the first step in the test design process. Here's how it works:
- Identify Requirements: Understand the functionality you are about to test.
- Formulate Logical Conditions: Describe the different logical scenarios that could exist based on input and expected behavior. For instance:
- Input data is of a certain type (e.g. integer, string).
- Input data satisfies a specific condition (e.g. within a range, not null).
- Operation should return true or false, without assigning actual values.
- Derive Concrete Tests: Convert the logical tests into specific test cases by assigning actual values for the input, and define the expected outputs precisely.
Benefits of Using Logical Test Cases
- Clarity: They provide an easier-to-understand description of the tests to be performed for the requirements.
- Reusability: Logical test cases can be used across different data sets to create multiple concrete test cases, ensuring wide coverage.
- Maintainability: When changes are made to the code, the impact on logical conditions is assessed more easily than with concrete test cases alone.
- Flexibility: They can be used to generate concrete test cases for different platforms and data ranges.
Conclusion
In essence, a logical test case is an abstract representation of a test, focusing on the conditions that must be validated. It provides a structured framework for further development of implementation-specific concrete test cases that verify the functionality using real data.
