In this case like in many other cases, there's not just a
single right answer because you can build many test cases that will
satisfy this test specification. So for example, we could pick value 3
for a and value 9 for b. Those satisfy the specification because a
plus b is equal to 12 and therefore is greater than 0,
and therefore this is a test case that implements this test specification.
And in terms of results, what we expect to see is in
the case of a result greater than 0, the caller should be red,
and the upper value should be 12. And obviously for this test
specification, we just need to pick two inputs such that the sum
of the two inputs is less than 0. So for example, we
could pick minus 5 and minus 8. The output color in this
case is going to be blue, and the output value is going to be
minus 13. So, what we just saw is basically how we can
go from a piece of code to a set of requirements, which
are the interesting aspects of the code that we want to exercise. How we
can satisfy the requirements by finding
the right test specifications, and then how
we can initiate the test specifications into actual test cases. And this is
what we will do in general when doing white books testing. And we'll
do things likely different way, depending on
the specific criteria that we are considering.