What is Path Coverage Testing?

Path Coverage testing is a structured testing technique for designing test cases with intention to examine all possible paths of execution at least once.

• Creating and executing tests for all possible paths results in 100% statement coverage and 100% branch coverage.
• In this type of testing every statement in the program is guaranteed to be executed at least one time. Flow Graph, Cyclomatic Complexity are used to arrive at basis path

Cyclomatic Complexity

• • Cyclomatic Complexity is a software metric used to indicate the complexity of a program.
  • Cyclomatic Complexity refers to the number of minimum test cases for a white boxed code which will cover every execution path in the flow.

For example:
if a>b
//do something
else
//do something else

In the above code, cyclomatic complexity is 2 as minimum 2 test cases to cover all the possible execution path in the known code.

Cyclomatic Complexity is computed in one of three ways:

1. 1. 1. The numbers of regions of the flow graph correspond to the Cyclomatic complexity.

      2. Cyclomatic complexity, V(G), for a flow graph G is defined as

         V(G) = E – N + 2

         where E = number of flow graph edges  and N = is the number of flow graph nodes.

      3. Cyclomatic complexity, V(G), for a graph flow G is also defined as

         V(G) = P + 1

         Where P = number of predicate nodes contained in the flow graph G.

Advantages of  Path Testing:

• • • Path Testing helps reducing redundant tests
    • Focus on program logic
    • Test cases will execute every statement in a program at least once

PathCoverage =  Number of Paths Covered/ Number of Total Paths

Example of Path Coverage Testing

Read A  
Read B  
IF A+B > 50 THEN  
Print "Large"  
ENDIF  
If A+B<50 THEN  
Print "Small"  
ENDIF