Scenariographer: a tool for reverse engineering class usage scenarios from method invocation sequences

Typical documentation for object-oriented programs includes descriptions of the parameters and return types of each method in a class, but little or no information on valid method invocation sequences. Knowing the sequence with which methods of a class can be invoked is useful information especially for software engineers (e.g., developers, testers) who are actively involved in the maintenance of large software systems. This paper describes a new approach and a tool for generating class usage scenarios (i.e., how a class is used by other classes) from method invocations, which are collected during the execution of the software. Our approach is algorithmic and employs the notion of canonical sets to categorize method sequences into groups of similar sequences, where each group represents a usage scenario for a given class.