Property-Based Testing with External Test-Case Generators

Previous work has demonstrated that property-based testing (PBT) is a flexible
random testing technique that facilitates the generation of complex form data.
For example, it has been shown that PBT can be applied to web-service
applications that require various inputs for web-forms. We want to exploit this
data generation feature of PBT and combine it with an external test-case
generator that can generate test cases via model-based mutation testing.
PBT already supports the generation of test cases from stateful models, but it
is limited, because it normally only considers the current state during
exploration of the model. We want to give the tester more control on how to
produce meaningful operation sequences for test cases. By integrating an
external test-case generator into a PBT tool, we can create test cases that
follow certain coverage criteria. This allows us to reduce the test execution
time, because we do not need a large number of random tests to cover certain
model aspects. We demonstrate our approach with a simple example of an external
generator for regular expressions and perform an industrial case study, where
we integrate an existing model-based mutation testing generator.