  Regular, automated testing is a foundational principle of modern software
development. Numerous widely-used continuous integration systems exist, but
they are often not suitable for the unique needs of scientific simulation
software. Here we describe the testing infrastructure developed for and used by
the Modules for Experiments in Stellar Astrophysics (MESA) project. This system
allows the computationally-demanding MESA test suite to be regularly run on a
heterogeneous set of computers and aggregates and displays the testing results
in a form that allows for the rapid identification and diagnosis of
regressions. Regularly collecting comprehensive testing data also enables
longitudinal studies of the performance of the software and the properties of
the models it generates.
