WHITE BOX TESTING (WBT)

Entire WBT is done by developers. It is the testing of each and every line of code in the program. Developers do WBT, sends the s/w to testing team. The testing team does black box testing and checks the s/w against requirements and finds any defects and sends it to the developer. The developers fixes the defect and does WBT and sends it to the testing team. Fixing defect means the defect is removed and the feature is working fine.

Test engineers should not be involved in fixing the bug because,

1) if they spend time in fixing the bug, they lose time to catch some more other defects in the s/w

2) fixing a defect might break a lot of other features. Thus, testers should always identify defects and developers should always be involved in fixing defects.

W B T consists of the following tests :

1.Path testing.

2.Condition testing.

3.Loop testing.

Path testing

Write flow graphs and test all the independent paths.

Writing flow graphs means – flow graphs means representing the flow of the  program, how each program is interlinked with one another.

Flow Graph

Test all independent paths – Consider a path from main( ) to function 7. Set the parameters and test if the program is correctly in that path. Similarly test all other paths and fix defects.

Condition testing

Test all the logical conditions for both true and false values i.e, we check for both “if” and “else” condition.

If( condition) - true

{

                …….

                …….

}

Else - false

{

                …..

                …..

}

The program should work correctly for both conditions i.e, if condition is true, then else should be false and vice-versa.

Loop testing

Test the loops(for, while, do-while, etc) for all the cycles and also check for terminating condition if working properly and if the size of the condition is sufficient enough.