This document discusses white box testing techniques like path testing and control flow graphs. Path testing requires complete knowledge of a program's structure and is mostly used by programmers to unit test their own code. A control flow graph uses elements like process blocks, decisions, and junctions to represent a program's control structure graphically. Process blocks are sequences of statements without decisions or junctions, while decisions and junctions diverge and merge the control flow. Path testing aims to execute all possible paths through a program from entry to exit to achieve 100% path coverage.

1. White box design
techniques

2. #
Path testing
 A structural test technique
 Requires complete knowledge of the
programs structure.
 Mostly used by the programmers to unit
test their own code.

3. #
Control flow graph
 Control flow graph is a graphical
representation of programs control structure.
 It uses elements : process blocks , decisions ,
junctions.
Process block:
Process A

4. #
Control flow graph (contd..)
 Process block is a sequence of program
statements uninterrupted by either decisions
or junctions
 A process block can be one statement or
hundreds of statements or instructions.
 A process has one entry and one exit
 A program does not jump into or out of the
process.

5. #
Control flow graph(contd..)
Decision :
 A decision is a program point at which the
control flow can diverge
 When most decisions are two way some are
three way branches in control flow.
 A case statement is a multi way branch or
decision
If
A=B no
yes

6. #
Control flow graph(contd..)
junction :
 A junction is a point in the program where the
control flow can merge.
 Examples of junction : goto, continue
 A case statement is a multi way branch or
decision
1 2

7. #
Flow graph , flow chart
 White box testing is the detailed investigation
of internal logic and structure of the code
 White box testing is also called glass testing
or open box testing.

8. #
Path testing
 A path through a program is a sequence of
instructions or statements that starts at an
entry, junction , decision and ends at another
junction, decision ,exit.

9. #
fundamental path selection
criteria
• Exercise every path from entry to exit
• Exercise every statement or instruction
at least once.
• Exercise every branch and case
statement in each direction at least
once

10. #
• Path testing : execute all possible control flow
paths through the program. This is restricted
to all all possible entry/exit paths through the
program.
100% path coverage
Statement testing
Execute all statements in the program at least
once under some test
100% statement coverage
Branch testing
100% branch coverage