The document discusses various white box testing techniques: 1. Statement testing executes all statements in the code. 2. Branch/Decision Testing executes all outcomes (true/false) of decision points. 3. Branch Condition Combination Testing checks that each combination of inputs for a condition is tested to cover all branches. 4. Modified Condition Combination Testing independently tests each atomic condition to check its effect on the decision outcome.

1. SOFTWARE QUALITY ASSURANCE WHITE BOX Seminar: Oana FEIDI Quality Manager – Continental Automotive

2. White Box (Structural Testing) Structural - test case selection is based on an analysis of the internal structure of component Control flow Statement testing Branch/Decision Testing Branch Condition Testing Modified Condition Combination Testing Data flow testing

3. White Box Using the white-box testing techniques outlined in this seminar , a software engineer can design test cases that exercise independent paths within a module or unit; e xercise logical decisions on both their true and false side; execute loops at their boundaries and within their operational bounds exercise internal data structures to ensure their validity

4. Statement testing uses a model of the program’s control flow it is designed in order to execute all or selected statements of the test object An entity in a programming language which is typically the smallest indivisible unit of execution. Test cases are design to execute each statement. For each test case specify: the input(s) of the component identification of statement(s) to be executed by the test case the expected outcome of the test case Test completeness criteria : the percentage of the statements in the software which were executed at least at once (executing a statement means that the statement was encountered and evaluated during testing).

5. Example float foo (int a, int b, int c, int d, float e) { float e; if (a == 0) { return 0; } int x = 0; if ((a==b) OR ((c == d) AND bug(a) )) { x=1; } e = 1/x; return e; } statement

6. Branch/Decision Testing uses a model of the program’s flow it is designed in order to execute (each) outcome of all or selected decision points in a test object an executable statement which may transfer control to another statement, depending upon the logic of the decision statement For each test specify: the input(s) of the component Identification of decision outcome(s) to be executed by the test case the expected outcome of the test case Test completeness criteria : achievement of the test coverage – 100% of the branches (one true and one false for each part of condition)

7. Example A = true and (B or C) = false A = false and (B or C) = true if A and (B or C) Case A B C Output 1 0 1 1 0 2 1 0 0 0

8. Branch Condition Combination uses a model of the program flow where each combination of the inputs for a decision/condition must be tested, in order to check if each branch is covered For each test case specify: the input(s) of the component the expected outcome of the test case which can show which branch is covered Test completeness criteria : for a condition containing n boolean operands -> 2 n test cases are required to achieve 100% coverage Note: this coverage rapidly becomes unachievable for more complex conditions.

9. Example Start if a & (b or c) End true false A = true, false B = true, false C = true, false Exercise !!! Case A B C Outcome

10. White Box - summary Statement testing uses a model of the program’s control flow it is designed in order to execute all or selected statements of the test object Branch/Decision Testing uses a model of the program’s flow it is designed in order to execute (each) outcome of all or selected decision points in a test object Branch Condition Combination uses a model of the program flow where each combination of the inputs for a decision/condition must be tested, in order to check if each branch is covered

11. Can we discover the mistake? What happens if we have: IF(A AND (B AND C)) instead of IF (A AND (B OR C)) Exercise : Verify if using Branch/Decision testing and Branch Condition Combination testing we can discover the mistake.

12. Modified Condition Combination Testing uses a model of the program’s flow where each atomic condition is independently tested, in order to show how the decision outcome is affected test case are designed to show that each condition independently affects the decision outcome For each test case specify: the input(s) of the component The expected outcome of the test case

13. Modified Condition Combination Testing Test completeness criteria for a condition containing n boolean operands, to achieve 100% coverage are necessary: minimum: n + 1 test cases maximum: 2n test cases Example: for 3 boolean operands, to achieve 100% coverage are necessary: Minimum 4 test cases Maximum 6 test cases

14. Example if (A and (B or C)) Case A B B or C C Outcome 1 1 1 1 0 1 2 0 0 3 1 1 1 0 1 4 0 0 0 5 1 0 1 1 1 6 0 0 0

15. Loop Testing Simple Loops :- 'n' is the maximum number of allowable passes skip the loop entirely. only one pass thru the loop. two passes thru the loop. m passes thru the loop where m< n. n-1,n,n+1 passes thru the loop Nested loops start with the innermost loop. Set all other loop to min. values. conduct simple loop tests for the innermost loop while holding the outer loops at their min. iteration values. work outward, conducting tests for the next loop, but keeping all the outer loops at their min. iteration count. continue until all loops have been tested.