11S3112 PPMPL

White Box Testing : Control Flow Coverage Part 1

Week 4 Session 1Tahun Ajaran 21/22

Lecturer : ACB Teaching Assistant: Apria

- PPMPL 11S3112–- Sem Ganjil 2021/2022 -

Institut Teknologi DelJl. SisingamangarajaSitoluama, Laguboti 22381Toba – SUMUThttp://www.pidel.org

• What is white box testing ?• Advantages and disadvantages• Importance of coverage based testing• Control flow coverage• Test suite generation using coverage

based testing

9/12/21 ACB

Overview

• Known as code-based testing or glass box testing or structural testing

• Generate test cases based on the program source and on the internal workings of the source

9/12/21 ACB

What is White Box Testing ?

9/12/21 ACB

White Box Testing – A common view

PROGRAM…IF (a>b) then

Do somethingElse

Do other Things….

INPUT OUTPUT

TEST CASE SELECTION STRATEGIES

• Advantagesq Test implemented modules, specially ones that have not been specifiedq Therefore faults in such modules can be detected, but not in black box

testing

• Disadvantagesq Not test specified but not implemented modules (why is this important?)q Testing cannot be conducted before coding / implementation completedq Need to have programming skills

9/12/21 ACB

Advantages and Disadvantages

• Coverage testing: a certain part of the program is not covered, we cannot know whether there are faults inside that part.

• Coverage criteriaq Control-flow coverageq Data-flow coverage

9/12/21 ACB

Intuition of white box testing

• Given a coverage criterion, list out all the items to be covered

• Find test cases to execute each item at least once

9/12/21 ACB

Procedure in coverage testing

• By program instrumentationInsert some printing statements to trace the program execution

9/12/21 ACB

How do we know that an item has beenexecuted?

• Control flow coverage testing:q statement coverage testingq branch / decision coverage testingq condition coverage (cc)qDecision/condition coverage (d/cc)q modified condition/decision coverage

(MC/DC)q multiple-condition coverage (M-CC)

• Data flow coverage testingq all-defs, all-c-uses, all-p-uses, all-c-

uses/some-p-uses, all-p-uses/some-c-uses, all-uses, and all-du-paths

9/12/21 ACB

Classification

• Node: A block of statements that is not separated by any branch

• Edge: link between nodes

• Branch: An edge, associated with the true or false branch of a decision node (or called predicate)For example, Node 2 (5th line of code) is a decision node, which has two out-going edges (b and d) b and d are called the branches of Node 2. Each edge is labeled as a character, that is, a, b, c, … in the next 2 slide

9/12/21 ACB

Node, Edge, and Branch

1 Sub F1 (int a, int b)2 {3 int z; \\ S14 z = 5 ; \\ S25 if (a>1) && (b==0) \\ S36 {7 a = a + 10; \\ S48 }9 z= z + a + b \\ S510 print z; \\ S611 }

9/12/21 ACB

Example: find the nodes

1 Sub F1 (int a, int b)2 {3 int z; \\ S1 N14 z = 5 ; \\ S2 5 if (a>1) && (b==0) \\ S3 N26 {7 a = a + 10; \\ S4 N38 }9 z= z + a + b \\ S5 N410 print z; \\ S611 }

9/12/21 ACB

Example: find the nodes

9/12/21 ACB

Example: Control Flow Graph

1

3

4

2

START

END

a

b

c

d

1Public int getExtraHours()2{3 int hours, i; //s14 hours = 0; //s25 i = 0; //s36 while (i < numSession) //s47 {8 if (session[i].status == EXTRA) //s59 {10 hours = hours + session[i].duration; //s611 }12 else 13 {14 hours = hours //s8 15 }16 i++; //s917}18return hours; //s1019}

Program under study:determine the nodes !

9/12/21 ACB

1Public int getExtraHours()2{3 int hours, i; //s1, node14 hours = 0; //s25 i = 0; //s36 while (i < numSession) //s4, node27 {8 if (session[i].status == EXTRA) //s5, node39 {10 hours = hours + session[i].duration; //s6, node411 }12 else 13 {14 hours = hours //s8, node 5 15 }16 i++; //s9, node617}18return hours; //s10, node719}

Program under study: The Nodes

9/12/21 ACB

9/12/21 ACB

Control Flow Graph

1

23

4

5

7

START

END6

1Public int getExtraHours()2{3 int hours, i;//s1, node14 hours = 0; //s25 i = 0; //s36 while (i < numSession) //s4, node27 {8 if (session[i].status == EXTRA) //s5, node39 {10 hours = hours + session[i].duration; //s6, node411 }12 else 13 {14 hours = hours //s8, node 5 15 }16 i++; //s9, node617 }18 return hours; //s10, node719}