White box testing

White box testing, by contrast to black box testing, is when the tester has access to the internal data structures and algorithms (and the code that implement these)

Types of white box testing

The following types of white box testing exist:

• api testing(application programming interface) - Testing of the application using Public and Private APIs.
• code coverage - creating tests to satisfy some criteria of code coverage. For example, the test designer can create tests to cause all statements in the program to be executed at least once.
• fault injection methods.
• mutation testing methods.
• static testing - White box testing includes all static testing.

Code completeness evaluation

White box testing methods can also be used to evaluate the completeness of a test suite that was created with black box testing methods. This allows the software team to examine parts of a system that are rarely tested and ensures that the most important function points have been tested.^[21]

Two common forms of code coverage are:

• function coverage, which reports on functions executed
• and statement coverage, which reports on the number of lines executed to complete the test.

They both return a coverage metric, measured as a percentage.