Testing I/O Failures with Enforcer

Testing application behavior in the presence of I/O failures is extremely difficult. The resources used for testing usually work without failure. Failures typically cannot be initiated on the test suite level and are usually not tested sufficiently. Essentially, each interaction of the application with the environment can result in a failure, making failures hard to test. The Enforcer tool identifies such potential failures and automatically tests all relevant outcomes of such actions. It combines the structure of unit tests, coverage information, and fault injection. By taking advantage of a unit test infrastructure, performance can be improved by orders of magnitude compared to previous approaches. This paper introduces the usage of the Enforcer tool.