A system and method for automatically detecting heap corruption errors and memory leak errors caused by user-supplied code modules that are called by steps of a test executive sequence. The test executive sequence may first be created by including a plurality of test executive steps in the test executive sequence and configuring at least a subset of the steps to call user-supplied code modules. The test executive sequence may then be executed on a host computer under control of a test executive engine. For each step that calls a user-supplied code module, the test executive engine may perform certain actions to automatically detect whether the user-supplied code module causes a heap corruption error and/or automatically detect whether the user-supplied code module causes a memory leak error.