run-tests

name	run-tests
description	Run targeted JustPIC tests, prioritized by what's likely to break

Run Tests

Run targeted tests first, prioritized by what's most likely to fail given recent changes. Only fall back to the full suite once the targeted files pass.

Step 1: Identify What Changed

Map the changed area to test files (testsets for a feature usually exist in both test_2D.jl and test_3D.jl):

Changed area	Test files to run first
src/Particles/ (move/injection/utils)	test_2D.jl, test_3D.jl (Particles initialization, Cell index, Forced injection, Miniapps testsets)
src/Particles/Advection/, src/Advection/	test_integrators.jl, then advection testsets in test_2D.jl/test_3D.jl
src/Interpolations/	test_interpolation_kernels.jl, Interpolations testsets in test_2D.jl/test_3D.jl
src/CellArrays/, src/launch.jl	test_CellArrays.jl
src/MarkerChain/	test_save_load.jl (only existing coverage — consider adding testsets to test_2D.jl when touching this area)
src/PassiveMarkers/	Passive markers testsets in test_2D.jl/test_3D.jl
src/PhaseRatios/	Phase ratios testsets in test_CellArrays.jl
src/Physics/	Subgrid diffusion testsets in test_2D.jl/test_3D.jl
src/IO/	test_save_load.jl
Exports / Project.toml / new deps	test_Aqua.jl
ext/	full GPU run (--backend=CUDA) — extensions are only exercised there

Step 2: Run the Most Likely File First

Single file, CPU (fast iteration; needs TestEnv in your default env once: julia -e 'using Pkg; Pkg.add("TestEnv")'):

julia --project=. -e 'using TestEnv; TestEnv.activate();
                      ENV["JULIA_JUSTPIC_BACKEND"] = "CPU";
                      include("test/test_2D.jl")'

Swap the env var to "CUDA" / "AMDGPU" to run the same file on a GPU.

Step 3: Fix and Iterate

1. Fix the failure, re-run the same file to confirm
2. Move to the next most likely file
3. Run test_Aqua.jl for any change touching exports, deps, or method signatures (ambiguity checks)

Step 4: Full Suite Before Handing Off

julia --project=. -e 'using Pkg; Pkg.test()'                                   # CPU
julia --project=. -e 'using Pkg; Pkg.test(; test_args=["--backend=CUDA"])'     # GPU

Notes

• New test_*.jl files must be registered in test/runtests.jl (both the CPU include list and the gpu_testfiles tuple) or they never run
• GPU-only failures are usually type instability — reproduce on CPU first
• The GPU path spawns a subprocess per file with --project=<Pkg.test sandbox>; that flag is load-bearing, don't "simplify" it away