What does path coverage aim to ensure during testing?

Path coverage is a testing criterion that focuses on ensuring that every feasible path through a given program segment is executed at least once during testing. This is important because software can have multiple paths dictated by conditional branching, loops, and logical constructs. By executing all feasible paths, testers can reveal hidden defects that may occur only in specific sequences of execution, helping to ensure comprehensive testing of the program's logic and control flow.

Achieving full path coverage is a rigorous approach that greatly enhances the likelihood of discovering issues that other testing methods might overlook, such as edge cases or rarely executed code paths. This method provides deeper insights into the program's behavior and enhances the overall quality and reliability of the software being tested.

While executing each line of code at least once or ensuring the application behaves as expected with valid inputs are important in their own right, they do not provide the same level of coverage and assurance about the control flow that path coverage does. Testing all functions of the application is also vital but does not guarantee that specific paths within those functions are thoroughly validated. Therefore, focusing on feasible paths is essential for comprehensive test coverage.