Schaum's Outline Series

150
By the fourth test case, every statement has been executed. This set of test cases
is not the smallest set that would cover every statement. However, finding the
smallest test set would often not find a good test set.
10.3.4.2 C1—Every-Branch Testing
A more thorough test criterion is every-branchtesting, which is often called C1 test
coverage. In this criterion, the goal is to go both ways out of every decision.
EXAMPLE 10.4
If we model the program of Example 10.3 as a control flow graph (see Chapter 2),
this coverage criterion requires covering every arc in the control flow diagram. See
Fig. 10-1.
A,B,C
E
G
I
K
Fig. 10-1. Control flow graph for
Example 10.3.
10.3.4.3 Every-Path Testing
D
F
H
J
CHAPTER 10 Software Testing
Arcs 3,4,5 3,5,3 0,1,0 4,4,4
ABC–D * * *
ABC–E*
D–E* * *
E–F *
E–G * * *
F–G *
G–H *
G–I * * *
H–I *
I–J *
I–K * * *
J–K *
Even more thorough is the every-pathtesting criterion. A path is a unique sequence
of program nodes that are executed by a test case. In the testing matrix (Example
10.2) above, there were eight subdomains. Each of these just happens to be a path.
In that example, there are sixteen different combinations of T and F. However,
eight of those combinations are infeasible paths. That is, there is no test case that