Automatic Generation of Test Inputs for Mercury

Abstract

In this work, we consider the automatic generation of test inputs for Mercury programs. We use an abstract representation of a program that allows to reason about program executions as paths in a control-flow graph. Next, we define how such a path corresponds to a set of constraints whose solution defines input values for the predicate under test such that when the predicate is called with respect to these input values, the execution is guaranteed to follow the given path. The approach is similar to existing work for imperative languages, but has been considerably adapted to deal with the specificities of Mercury, such as symbolic data representation, predicate failure and non-determinism.

Towards a Framework for Constraint-Based Test Case Generation

“…Arguably the most commonly applied strategy for finding errors and thus producing (more) reliable software is testing: running a software component with respect to a wellchosen set of inputs and comparing the outputs that are produced with the expected results in order to find errors. In previous work [4], we have developed a technique that allows to automatically generate a set of test inputs for a given program written in the logic programming language Mercury. The basic idea of that technique, itself inspired by [20], is as follows: first, a path through the control-flow graph of a predicate is transformed into a set of constraints on the (input) variables of the predicate such that when the predicate is called with input values satisfying these constraints, its execution is guaranteed to follow the given path.…”

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“…3 We will assume that ImpL is simply typed and only allows comparison of two values belonging to the same type (either integers or references). 4 Moreover, arithmetic is only allowed on integer values; the language does not support pointer arithmetics.…”

“…It scans the list for two successive identical elements, and severs the list after the first such occurrence. For example, using the notation [1,2,3] for the nil-terminated linked list with successive elements 1,2 and 3, the effect of running this program with x the list [1,2,3,3,4], is that, after the while loop, the list will have the value [1,2,3].…”

Applying Constraint Logic Programming to SQL Test Case Generation

“…Other recent works [2] use RQP (Reverse Query Processing) to generate different database instances for a given query and a result of that query. In [6] the problem…”