1. A computer-readable memory medium storing program instructions executable to: include a plurality of test executive steps in a test executive sequence in response to user input; configure each respective step of the plurality of test executive steps to call a respective user-supplied code module in response to user input; determine an initial location on a stack before execution of the test executive sequence begins; and execute the test executive sequence, wherein said executing comprises executing each respective step of the plurality of test executive steps after determining the initial location; wherein executing each respective step comprises: storing a first portion of the stack ranging from the initial location to a current stack pointer location; invoking execution of the respective user-supplied code module called by the respective step; and checking the stored portion of the stack against contents of the stack after the respective user-supplied code module called by the respective step finishes executing to determine whether the first portion of the stack changed during execution of the respective user-supplied code module called by the respective step; wherein for each respective step of the plurality of test executive steps, said storing the first portion of the stack comprises storing a respective portion of the stack beginning at the same initial location.