Jawaharlal Nehru Technological University Hyderabad MCA V Semester SOFTWARE TESTING METHODOLOGIES Previous Question Paper (February - 2021 - R17)

The nightmare list is a prioritized collection of high-risk, complex, or critical scenarios that are most likely to cause system failure or catastrophic errors. It serves as a focus area for testers to ensure that the most problematic components of the software are subjected to rigorous scrutiny before release. Testing should stop when the following criteria are met: the nightmare list items are fully validated, all high-priority defects are resolved and verified, the software meets the pre-defined exit criteria (such as a specific pass rate or coverage percentage), and the remaining open defects are classified as low-risk or cosmetic issues that do not impact core functionality or user experience.

Path testing is a structural testing technique that aims to execute every independent path through a program's control flow graph (CFG). The implementation involves the following steps:

1. Construct the Control Flow Graph (CFG) of the code, representing nodes as statements and edges as the flow of control.
2. Calculate the Cyclomatic Complexity using the formula V(G) = E - N + 2P, where E is the number of edges, N is the number of nodes, and P is the number of connected components.
3. Identify a set of linearly independent paths based on the cyclomatic complexity value.
4. Design test cases to traverse each of these independent paths to ensure complete path coverage.

Path testing is applied during the unit testing phase to ensure that all logical branches and decision points are exercised. It is particularly effective for identifying hidden logic errors, redundant code, and complex conditional dependencies that might be missed by simpler testing methods. By ensuring every independent path is executed, developers can achieve a high degree of confidence in the internal logic of the software module.