Extra tutorial notes

1. Extra tutorial notes

2. Revision

3. Statement coverage and Branch coverage • Statement coverage – “Execute all statements in the program at least once under some test.” • Branch coverage – “Execute enough tests to assure that every branch alternative has been exercised at least once under some test.” References: Boris Beizer, Software Testing Techniques 2nd edition, 1990 (page 74).

4. Exercises

5. Revision

6. Notes • Assuming that red dots are global definition and green dot is the global c-use. • **The following is not a du-path: • Hence, when you are answering du-paths questions, please make sure that the path fulfills the requirements.

7. x=read(x) y=read(y) max=x x<y 1 2 3 4 x>y max = y 5 Exercise • Findpaths for x that satisfy the following criteria: • All-defs: • All-uses: • All-p-uses: • All-c-uses: • All-du-paths:

8. x=read(x) y=read(y) max=x x<y 1 2 3 4 x>y max = y 5 Exercise • Findpaths for x that satisfy the following criteria: • All-defs: {1,2,3} • All-uses:{1,2,3}, {1,2,3,4}, {1,2,3,5}, • All-p-uses: {1,2,3,4}, {1,2,3,5} • All-c-uses: {1,2,3} • All-du-paths = all-uses + {1,2,3,4,5}

9. Another testing questions

10. Suggested solutions • 0 • 0, 1 • Not possible because the loop does not have a fixed upper bound. We don’t know the value of “n” to execute the loop n-1, n and n+1 times. • Infinite number of test cases because the loop does not have a fixed upper bound. • Global definition: 1-2-3-4-5, 9-10 Global c-uses: 9-10, 11 du-paths: 1-2-3-4-5  9-10 1-2-3-4-5  7  9-10 1-2-3-4-5  11 9-10  9-10 9-10  11

11. An extra question • Propose test cases to achieve all-du-paths criterion of the variable “factorial”.

12. Solutions • 3 test cases: 3, 1, 0. • Remarks: • N = 3 • 1-2-3-4-5  9-10  9-10  11 • N = 0 • 1-2-3-4-5  7  9-10  11 • N = 1 • 1-2-3-4-5  11