Low-level test cases, also known as unit tests or component tests, focus on testing individual units or components of a software system in isolation.
Scope: These tests are concerned with the smallest building blocks of a system, such as functions, methods, or modules.
Purpose: The primary goal of low-level test cases is to verify that each unit of the software performs as intended and functions correctly. It helps identify and fix defects in the code at an early stage.
The advantages of low-level test cases include:
- Detailed Guidance: Novice testing personnel can depend on comprehensive information provided within the project. Low-level test cases furnish specific details and procedures necessary for the tester to execute the test case, including any data requirements, and to validate the actual results.
- Consistency in Results: Tests can be rerun by different testers, aiming to achieve consistent results.
- Uncovering Non-obvious Defects: Non-apparent defects in the test basis can be brought to light through the detailed examination at this level.
- Independent Verification: The level of detail allows for independent verification of the tests, including audits if necessary.
- Reduced Time for Automation: Implementation of automated test cases may require less time due to the detailed nature of low-level test cases.
However, low-level test cases come with certain drawbacks:
- Substantial Effort: The creation and maintenance of low-level test cases may demand a significant amount of effort.
- Limitation on Tester Creativity: During execution, these tests may restrict the ingenuity of testers.
- Dependency on Well-Defined Test Basis: Successful execution of low-level test cases necessitates a well-defined test basis.
- Traceability Challenges: Tracing these test cases back to test conditions might require more effort compared to high-level test cases.