Abstract
Code coverage tells you which lines your tests run, but not whether your tests would actually catch a bug in them. Mutation testing answers that question directly: it introduces small, systematic changes into the source code and checks whether the test suite detects them. In this talk I present mutator, an automated mutation testing tool for R packages. mutator mutates R source at the level of the abstract syntax tree, runs the package’s tests against each mutant, and reports which mutants are killed, survive, or time out, summarising the result as a mutation score. I discuss the mutation operators it supports, how it integrates with testthat and continuous integration, and the techniques it uses to keep mutation testing tractable, including parallel execution and coverage-guided test selection.
Pierre Donat-Bouillud
Researcher
My research interests including programming languages, fuzzing and testing.