Styles of Testing   

Testing traditionally can be conducted in three styles

• Black-Box testing
  • Try to choose "smart" tests based on the requirements, without looking at the code.
• White-Box testing
  • Try to choose "smart" tests based on the structure of the code, with minimal reference to the requirements.
• Random testing
  • Try to use directed random selection to choose tests that are "representative" of how the program will be used.

We’ve already looked at black-box techniques. In this lesson we take up white-box testing.

Complementary Strategies   

Black-box and white-box testing are complementary.

• projects should combine elements of each
• Black-box tests
  • can be designed earlier
  • are better at catching errors of omission and errors in design
• White-box tests
  • must await the development of the code
  • are better at catching errors of commission and errors after design

Combining Black- and White-Box Testing   

Best to

• Do BB testing first
• Measure how well your BB tests did at WB coverage
• Add tests as needed to achieve your WB goals

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