This document discusses white box testing, which is a software testing technique where testers have explicit knowledge of the internal workings of the code. It tests all paths in the code including statements, branches, paths, and conditions. The document defines these terms and provides formulas to calculate coverage metrics like statement coverage. It notes that white box testing can find hidden errors and optimize code but is also more expensive and complex than black box testing.

1. WHITE BOX TESTING
INTRODUCTION

2. SOFTWARE TESTING
• SOFTWARE TESTING IS THE PROCESS OF ANALYZING A SOFTWARE ITEM TO
DETECT THE DIFFERENCES BETWEEN EXISTING AND REQUIRED CONDITIONS
(THAT IS, BUGS) AND TO EVALUATE THE FEATURES OF THE SOFTWARE ITEM.
• TESTING: A PROCESS OF EXECUTING SOFTWARE WITH THE INTENT OF FINDING
ERRORS OR DEFECT AND VERIFY THAT SOFTWARE MEETS ITS REQUIREMENTS AS
PERCEIVED BY THE USER.
• GOOD TESTING: A HIGH PROBABILITY OF FINDING AS-YET-UNDISCOVERED
ERRORS
• SUCCESSFUL TESTING: DISCOVERS UNKNOWN ERRORS

4. WHITE BOX TESTING
• TESTING BASED ON AN ANALYSIS OF THE INTERNAL STRUCTURE OF THE COMPONENT
OR SYSTEM.
• WHITE-BOX/STRUCTURE-BASED MEASURES AND ITS RELATED DESIGN TECHNIQUES ARE
DESCRIBED IN BS7925-2 STANDARD.
• A SOFTWARE TESTING TECHNIQUE WHEREBY EXPLICIT KNOWLEDGE OF THE INTERNAL
WORKINGS OF THE ITEM BEING TESTED ARE USED TO SELECT THE TEST DATA.
• WHITE BOX TESTING IS BASED ON SPECIFIC KNOWLEDGE OF THE SOURCE CODE TO
DEFINE THE TEST CASES AND TO EXAMINE OUTPUTS.
• E.G., WRITE TESTS TO “COVER” INTERNAL PATHS
• INTERNAL STRUCTURE IS KNOWN TO THE TESTER

5. WHITE BOX TESTING
• WHITE BOX TESTING CAN BE APPLIED AT THESE KIND OF TESTING.
• UNIT TESTING
• MODULE TESTING
• SYSTEM TESTING

6. Statement Coverage
Branch Coverage
Path Coverage
Conditional
Coverage

7. WHITE BOX TECHNIQUESCODE COVERAGE IS A MEASURE WHICH DESCRIBES THE DEGREE OF WHICH THE
SOURCE CODE OF THE PROGRAM HAS BEEN TESTED.
IT IS ONE FORM OF WHITE BOX TESTING WHICH FINDS THE AREAS OF THE
PROGRAM NOT EXERCISED BY A SET OF TEST CASES. IT ALSO CREATES SOME
TEST CASES TO INCREASE COVERAGE AND DETERMINING A QUANTITATIVE
MEASURE OF CODE COVERAGE.
IN MOST CASES, CODE COVERAGE SYSTEM GATHERS INFORMATION ABOUT THE
RUNNING PROGRAM. IT ALSO COMBINES THAT WITH SOURCE CODE
INFORMATION TO GENERATE A REPORT ABOUT THE TEST SUITE'S CODE
COVERAGE.
TYPES;
• STATEMENT COVERAGE TESTING
• PATH COVERAGE TESTING
• CONDITION COVERAGE TESTING
• MULTIPLE CONDITION TESTING

8. STATEMENT COVERAGE:
• THE PERCENTAGE OF EXECUTABLE STATEMENTS THAT HAVE BEEN EXERCISED
BY A TEST SUITE.
• IN A PROGRAMMING LANGUAGE, A STATEMENT IS NOTHING BUT THE LINE OF
CODE OR INSTRUCTION FOR THE COMPUTER TO UNDERSTAND AND ACT
ACCORDINGLY.
• STATEMENT COVERAGE IS A WHITE BOX TEST DESIGN TECHNIQUE WHICH
INVOLVES EXECUTION OF ALL THE EXECUTABLE STATEMENTS IN THE SOURCE
CODE AT LEAST ONCE. IT IS USED TO CALCULATE AND MEASURE THE NUMBER
OF STATEMENTS IN THE SOURCE CODE WHICH CAN BE EXECUTED GIVEN THE
REQUIREMENTS.
• STATEMENT COVERAGE = NUMBER OF STATEMENTS EXERCISED / TOTAL
NUMBER OF STATEMENTS * 100%

9. STATEMENT COVERAGE:
1A-2C-3D-E-4G-5H = 1
TOTAL STATEMENTS = 5
COVERED STATEMENTS = 3
STATEMENT COVERAGE =
(3/5)*100
60% OF STATEMENT
COVERAGE

10. BRANCH COVERAGE
• IN THE BRANCH COVERAGE, EVERY OUTCOME FROM A CODE MODULE IS TESTED. FOR
EXAMPLE, IF THE OUTCOMES ARE BINARY, YOU NEED TO TEST BOTH TRUE AND FALSE
OUTCOMES.
• “BRANCH” IN A PROGRAMMING LANGUAGE IS LIKE THE “IF STATEMENTS”. AN IF
STATEMENT HAS TWO BRANCHES: TRUE AND FALSE.
• IT HELPS YOU TO ENSURE THAT EVERY POSSIBLE BRANCH FROM EACH DECISION
CONDITION IS EXECUTED AT LEAST A SINGLE TIME.
• BY USING BRANCH COVERAGE METHOD, YOU CAN ALSO MEASURE THE FRACTION OF
INDEPENDENT CODE SEGMENTS. IT ALSO HELPS YOU TO FIND OUT WHICH IS SECTIONS
OF CODE DON'T HAVE ANY BRANCHES.
• THE FORMULA TO CALCULATE BRANCH COVERAGE:

11. BRANCH COVERAGE = 2
1A-2C-3D-E-4G-5H
1A-2B-E-4F
TOTAL BRANCHES= 4
COVERED BRANCHES=2
CALCULATE THE
BRANCH/DECISION COVERAGE =
(2/4)*100
YOUR TEST CASE, THEREFORE,
HAS 50% OF STATEMENT
COVERAGE

12. PATH COVERAGE:
• PATH COVERAGE TESTS ALL THE PATHS OF THE PROGRAM. THIS IS A
COMPREHENSIVE TECHNIQUE WHICH ENSURES THAT ALL THE PATHS OF THE
PROGRAM ARE TRAVERSED AT LEAST ONCE.
• PATH COVERAGE IS EVEN MORE POWERFUL THAN BRANCH COVERAGE. THIS
TECHNIQUE IS USEFUL FOR TESTING THE COMPLEX PROGRAMS.

13. PATHS THAT YOU CAN TAKE TO TRAVEL
IN THE FLOW CHART FROM THE START TO
THE END.
YOU CAN COVER ALL THE PATHS IN THE
FLOWCHART BY WRITING 4 TEST CASES
THAT FOLLOW THE FOLLOWING FOUR
ROUTES
1A-2B-E-4F
1A-2B-E-4G-5H
1A-2C-3D-E-4G-5H
1A-2C-3D-E-4F
PATH COVERAGE = 4
THERE ARE TOTAL OF 4 PATHS IN YOUR
FLOWCHART
YOU COVER ONLY 1 PATH
CALCULATE THE PATH COVERAGE =
(1/4)*100
THEREFORE IT HAS 25% OF PATH

14. CONDITION COVERAGE:
• IN THIS WHITE BOX TESTING TECHNIQUE TRY TO COVER 100% CONDITION
COVERAGE OF THE CODE, IT MEANS WHILE TESTING THE EVERY POSSIBLE
CONDITIONS IN THE CODE IS EXECUTED AT LEAST ONCE.
• CONDITIONAL COVERAGE OR EXPRESSION COVERAGE WILL REVEAL HOW
THE VARIABLES OR SUBEXPRESSIONS IN THE CONDITIONAL STATEMENT
ARE EVALUATED. IN THIS COVERAGE EXPRESSIONS WITH LOGICAL
OPERANDS ARE ONLY CONSIDERED.
• FOR EXAMPLE, IF AN EXPRESSION HAS BOOLEAN OPERATIONS LIKE AND,
OR, XOR, WHICH INDICATED TOTAL POSSIBILITIES.

15. FOR THE ABOVE EXPRESSION, WE HAVE 4 POSSIBLE COMBINATIONS
• TT
• FF
• TF
• FT
CONSIDER THE FOLLOWING INPUT
X=3
Y=4
(x<y) TRUE Condition
Coverage is ¼ =
25%
A=3
B=4
(a>b) FALSE

16. ADVANTAGES
• IT HELPS IN OPTIMIZING THE CODE.
• EXTRA LINES OF CODE CAN BE
REMOVED.
• DUE TO THE TESTER'S KNOWLEDGE
ABOUT THE CODE, MAXIMUM
COVERAGE IS ATTAINED DURING
TEST SCENARIO WRITING.
• CODE OPTIMIZATION BY FINDING
HIDDEN ERRORS.
• WHITE BOX TESTS CASES CAN BE
EASILY AUTOMATED.
• TESTING IS MORE THOROUGH AS ALL
CODE PATHS ARE USUALLY
COVERED.
• TESTING CAN START EARLY IN SDLC
DISADVANTAGES
• COSTS EXPENSIVE METHOD OF TESTING.
• IT IS DIFFICULT TO MAINTAIN WHITE BOX
TESTING AS THE USE OF SPECIALIZED
TOOLS LIKE CODE ANALYZERS AND
DEBUGGING TOOLS ARE REQUIRED.
WHITE BOX TESTING CAN BE QUITE
COMPLEX AND EXPENSIVE.
• DEVELOPERS WHO USUALLY EXECUTE
WHITE BOX TEST CASES DETEST IT. THE
WHITE BOX TESTING BY DEVELOPERS IS
NOT DETAILED CAN LEAD TO
PRODUCTION ERRORS.
• WHITE BOX TESTING REQUIRES
PROFESSIONAL RESOURCES, WITH A
DETAILED UNDERSTANDING OF
PROGRAMMING AND IMPLEMENTATION.
• WHITE-BOX TESTING IS TIME-

17. THANK YOU!