What is an infeasible path in software testing?

An infeasible path in software testing is a path that is impossible to achieve with any set of inputs. During software testing, each of the multiple paths of a program is executed and validated, but infeasible paths are impossible to execute.

Cons of infeasible paths

• Infeasible paths consume time and money in the testing process.
• Infeasible paths are present obstacles for automated testing.
• Infeasible paths can produce deadlocks and be a bottleneck in the testing process.
• Infeasible paths present problems for white-box testing because they use the program’s code and structure to create test cases and then execute them.

Example of an infeasible path

The following lines of code present examples of feasible and infeasible paths.

• If the input is less than 50, the path followed will be A, B, C, E, G.
• If the input is more than 50 but less than 90, the path followed will be A, B, D, E, G.
• If the input is more than 90, the path followed will be A, B, D, E, F, G.

However, under no circumstances can the path A, B, C, E, F, G be executed, because F cannot execute if C executes.

A: marks(input)
B: if marks < 50
C: then b = 2
D: else c = 3
E: if marks > 90
F: then d = 4
G: End