This Small Business Innovation Research Phase I project will conduct research to design a system for the unit testing of modules. This system will operate by automatically capturing events at the boundary of the module under test while a client of the module executes test cases. These events will be logged to a file so that they can later be replayed to the module in isolation. It is proposed to use Aspect-Oriented Programming (AOP) techniques to implement this tool and to use a third-party open-source licensed tool named AspectJ to implement this tool for Java. <br/> Unit testing solutions offer considerable cost-savings by automating the recording and playback of events for testing by organizations that either develop or use software.