This document discusses various techniques for white-box testing including statement coverage, branch coverage, path coverage, condition coverage, and loop testing. It provides examples of control flow graphs and describes designing test cases to execute every statement, branch, path, and condition. Loop testing techniques are outlined such as varying loop boundary values and testing nested, concatenated, and unstructured loops.

2. Created By
Ronak Ahir (ME-CSE) Enrolment No : 140870702501
Ankit Mulani (ME-CSE) Enrolment No : 140870702504

3.  White Box Testing
 Control Flow & Control Flow Graph
 Loop Testing

4. Designing white-box test cases:
Requires knowledge about the
internal structure of software.
White-box testing is also called
structural testing.

5.  Statement coverage
 Branch coverage
 Path coverage
 Condition coverage
There Exist Several Popular White-
box Testing Methodologies

6.  Design test cases so that every
statement in a program is
executed at least once.

7.  The Principal Idea
 Unless a statement is executed,
 We have no way of knowing if an error exists in
that statement
 Based on the observation
 An error in a program can not be Discovered
 Unless the part of the program containing the
error is executed

8.  Test cases are designed such that
 different branch conditions
 given true and false values in turn
 Branch Testing guarantees statement coverage
 A stronger testing compared to the statement
coverage-based testing

9.  Why “…and that every program entry point will
have been taken, at least once”?

10.  Design test cases such that
 All linearly independent paths
in the program are executed at
least once.

11.  It is straight forward
 To identify linearly independent
paths of simple programs
 For complicated programs
 It is not so easy to determine the
number of independent paths

12. The Tester Proposes
An Initial set of test data using
his experience and Judgment

13.  Test cases are designed such that
 each component of a composite conditional
expression given both true and false values
 If We Consider a Boolean expression having n
components
 Then For condition coverage we require 2n
test
cases

14. if A or B then
s1
else
s2
end_if_then_else
if A or B then
s1
else
s2
end_if_then_else

15.  To Understand the Path Coverage-Based
Testing We Need to Learn How to Draw
Control Flow Graph of a Program
 A Control Flow Graph (CFG) Describes
 The Sequence in which Different Instructions
of a Program get Executed
 The Way Control Flows Through the Program

16.  Number all the Statements of a Program
 Numbered Statements Represent nodes of the
Control Flow Graph.
 An Edge from one node to another node exists
 If execution of the statement representing the
first node can result in transfer of control to
the other node.

17. Flow Graph Example
1
2
0
3
4
5
6
7 8
9
1011
1
2
3
46
7 8 5
9
1011
R1
R2
R3
R4
FLOW CHART FLOW GRAPH
0

18. Example of Control Flow
Graph
1
2
3 4
5
6

19.  A white-box testing technique that focuses
exclusively on the validity of loop constructs
 Four different classes of loops exist
 Simple loops
 Nested loops
 Concatenated loops
 Unstructured loops
 Testing occurs by varying the loop boundary
values

20.  Skip the loop entirely
 Only one pass through the loop
 Two passes through the loop
 m passes through the loop, where m < n
 n –1, n, n + 1 passes through the loop
Note : ‘n’ is the maximum number of allowable passes through the loop

21.  Start at the innermost loop ; set all other loops to
minimum values
 Conduct simple loop tests for the innermost loop
while holding the outer loops at their minimum
iteration parameter values; add other tests for out-
of-range or excluded values
 Work outward, conducting tests for the next loop,
but keeping all other outer loops at minimum
values and other nested loops to “typical” values
 Continue until all loops have been tested

22.  For independent loops, use the same approach as
for simple loops
 Otherwise, use the approach applied for nested
loops

23.  Redesign the code to reflect the use of structured
programming practices
 Depending on the resultant design, apply testing
for simple loops, nested loops, or concatenated
loops