Incremental Control Dependency Frontier Exploration for Many-Criteria Test Case Generation

Several criteria have been proposed over the years for measuring test suite adequacy. Each criterion can be converted into a specific objective function to optimize with search-based techniques in an attempt to generate test suites achieving the highest possible coverage for that criterion. Recent work has tried to optimize for multiple-criteria at once by constructing a single objective function obtained as a weighted sum of the objective functions of the respective criteria. However, this solution suffers the problem of sum scalarization, i.e., differences along the various dimensions being optimized get lost when such dimensions are projected into a single value. Recent advances in SBST formulated coverage as a many-objective optimization problem rather than applying sum scalarization. Starting from this formulation, in this work, we apply many-objective test generation that handles multiple adequacy criteria simultaneously. To scale the approach to the big number of objectives to be optimized at the same time, we adopt an incremental strategy, where only coverage targets in the control dependency frontier are considered until the frontier is expanded by covering a previously uncovered target.