Testing

The test suite is run with the Julia package manager:

import Pkg; Pkg.test("ImplicitGlobalGrid")

Each test file runs in its own Julia process. Test files can be selected by name:

import Pkg; Pkg.test("ImplicitGlobalGrid"; test_args=["test_update_halo.jl"])

The GPU tests run if CUDA or AMDGPU is functional, and are skipped otherwise. The following environment variables control the test run:

Variable	Description
IGG_TEST_NPROCS	Number of MPI processes for the multi-rank test files (default: 1); all other test files run with a single process.
IGG_TEST_MPIEXEC	MPI launcher overriding MPI.mpiexec() (e.g. "srun --overlap" within a Slurm allocation); if set, all test files are launched with it.
IGG_TEST_BACKEND	GPU backend that must be functional (CUDA or AMDGPU); if it is not, the test run fails instead of skipping the GPU tests.

For example, to run the multi-rank tests with 4 processes (on GPUs: on a GPU node within a Slurm allocation):

CPUs

export IGG_TEST_NPROCS=4
julia --project -e 'import Pkg; Pkg.test()'

Nvidia GPUs

export IGG_TEST_NPROCS=4 IGG_TEST_BACKEND=CUDA IGG_TEST_MPIEXEC="srun --overlap"
julia --project -e 'import Pkg; Pkg.test()'

AMD GPUs

export IGG_TEST_NPROCS=4 IGG_TEST_BACKEND=AMDGPU IGG_TEST_MPIEXEC="srun --overlap"
julia --project -e 'import Pkg; Pkg.test()'

As the tests select the GPU by node-local MPI rank, every rank must see all GPUs of its node (no per-task GPU binding).

Continuous integration

• GitHub Actions (CPU): Julia min, 1 and pre on one process, the multi-rank tests on 4 and 8 processes, and the Polyester code path with multiple threads (.github/workflows/ci.yml).

• CSCS CI on Alps, with one pipeline per vCluster:

  • Daint (Nvidia GH200 GPUs): the full test suite on one process, the multi-rank tests on 1 node × 4 processes (with and without CUDA-aware MPI) and on 2 nodes × 4 processes, and the Polyester code path (ci/cscs-gh200.yml; pipelines). The multi-rank jobs only run if the single-process job passes.

  • Beverin (AMD MI250X and MI300A GPUs): the full test suite on one process, on each GPU type (ci/cscs-mi250.yml, ci/cscs-mi300.yml; MI250X pipelines, MI300A pipelines).

Coverage of all jobs is uploaded to Codecov (flags cpu, gh200, mi250 and mi300).