Tests

python -m pytest
mpirun -n 2 python -m pytest
mpirun -n 4 python -m pytest
mpirun -n 1 python -m pytest -m examples

The default run is the serial suite: adjoint checks of every operator by the dot-product identity, finite-difference checks of the full adjoint on coarse 2D and 3D beams, repeated-evaluation and constraint gradient checks, material consistency checks, and regression values for the beam. The examples marker runs one iteration of every example input and compares the first objective with the recorded value; run it under mpirun as well, since some errors only appear with more than one rank.