# Tutorial 8

1. Consider the deceptively simple program below. Consider the three initial values of `a`, `b` and `c` to be inputs to the program. So the search space for test data generation is a vector of three values `<a, b, c>`. In this exercise, we are concerned with branch and target coverage. There are four targets: 1, 2, 3, 4 in the program for which we wish to generate test data.
``````1int a, b, c
2
3if (a>b)
4    c = 1 /* target 1 */ ;
5else {
6    c = 2;
7
8    if (b==c)
9    /* target 2 */ ;
10}
11
12if (c==3)
13    do something; /* target 3 */ ;
14if (b==42)
15    do something else; /* target 4*/ ;``````

a). Consider the following 3 input vectors and show what each output each produces.

i). `<1, 2, 3>`

The program will reach `/* target 2 */` and end with `<1, 2, 2>`.

ii). `<-1, -1, 4>`

The program will end with `<-1, -1, 2>`.

iii). `<24, 52, 1>`

The program will end with `<24, 52, 2>`.

iv). None of these cover target 1. Which comes closest?

ii). comes closest as it gets closest to `a > b`.

b). Explain why it is not possible to cover target 3 in this program. Which input vector or vectors come closest to hitting target 3?

Because of the first if-else statement, `c` is always set to either `1` or `2`. When `a < b`, then `c = 2` and that is the closest the program gets to hitting target 3.

c). Which input vectors hit target 4?

`<1, 42, 2>`

d). Is it possible to achieve 100% branch coverage? If yes, give the test suite with 100% coverage. If not, explain why not and construct a test suite that covers all the reachable branches.

It is not possible to attain 100% branch coverage as target 3 is unreachable. The following test suite covers the other branches:

• : `<3, 2, 1>` (target 1)
• : `<1, 2, 1>` (target 2)
• : `<1, 42, 1>` (target 4)

This could be done with 2 test cases, but then you are combining 2 targets into one test.

1. Assume you have a part of a program:
``````1if ((a && b) || c) do X;
2else do Y;``````

Construct a test suite that gives 100% condition coverage; 100% branch coverage; 100% MC/DC.

Test Suite:

• : `TTT`
• : `TTF`
• : `TFF`
• : `FFF`
• : `FFT`
• : `FTT`
• : `FTF`
• : `TFT`

``````1a:
2  TTF = T x
3  FTF = F x
4b:
5  TTF = T
6  TFF = F x
7c:
8  TFT = T x
9  TFF = F
``````
1. Calculate the McCabe Number (cyclomatic complexity) for the following graphs:
• a).
• b).
• c).
• d).

a, b, c) are control flow graphs, whereas d is an arbitrary graph.