Introducing regression tests

.pre-commit-config.yaml

@@ -4,6 +4,7 @@
 #
 #   pixi run install-hooks   # one-off: install the git hooks
 #   pixi run lint            # run all hooks on all files
+exclude: ^tests/fairship_tests/references/
 repos:
   # prek runs these as native Rust builtins (no environment, fully portable).
   - repo: https://github.com/pre-commit/pre-commit-hooks

README.md

@@ -11,6 +11,7 @@
     - [Using pixi](#using-pixi)
     - [Run instructions](#run-instructions)
     - [Docker instructions](#docker-instructions)
+    - [Testing](#testing)
     - [Troubleshooting information](#troubleshooting-information)
     - [Documentation](#documentation)
     - [License](#license)
@@ -174,6 +175,20 @@ desirable.
     ```
     The option `-e DISPLAY=unix$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix` forwards graphics from the docker to your local system (similar to `ssh -X`). The option `-v /local_workdir:/image_workdir` mounts `/local_workdir` on the local system as `/image_workdir` within docker.
 
+## Testing
+
+Build and run the complete CTest suite, including the C++ and terminal-output
+regression tests, with:
+
+```bash
+pixi run test
+```
+
+Some regression tests download remote input data and therefore require network
+access. See [`tests/README.md`](tests/README.md) for commands that select
+individual tests or only the regression suite, and for instructions on adding
+tests and regenerating reference output.
+
 ## Troubleshooting information
 
 Please see the wiki for [FAQ](https://github.com/ShipSoft/FairShip/wiki/FAQ-and-common-issues#faq)s and [common issues](https://github.com/ShipSoft/FairShip/wiki/FAQ-and-common-issues#common-issues).

gconfig/DecayConfigTEvtGen.C

@@ -9,6 +9,14 @@ void DecayConfig() {
   // Create the custom EvtGen decayer
   TEvtGenDecayer* decayer = new TEvtGenDecayer();
 
+  // run_simScript exports the resolved command-line seed before VMC loads this
+  // macro. Pass it explicitly so initialization cannot advance the ROOT RNG
+  // and silently change the EvtGen/Pythia8-decayer seed.
+  TString RandomSeed = gSystem->Getenv("FAIRSHIP_RANDOM_SEED");
+  if (!RandomSeed.IsNull()) {
+    decayer->SetSeed(static_cast<UInt_t>(RandomSeed.Atoll()));
+  }
+
   // Configure EvtGen files using EVTGENDATA
   TString DecayFile = TString(gSystem->Getenv("EVTGENDATA")) + "/DECAY.DEC";
   TString ParticleFile = TString(gSystem->Getenv("EVTGENDATA")) + "/evt.pdl";

macro/run_simScript.py

@@ -479,6 +479,7 @@ def _fraction_0_1(value: str) -> float:
 if seed > 900000000:
     seed = seed % 900000000
 ROOT.gRandom.SetSeed(seed)
+os.environ["FAIRSHIP_RANDOM_SEED"] = str(seed)
 shipRoot_conf.configure(0)  # load basic libraries, prepare atexit for python
 if options.reproducible and options.debug == 0:
     ROOT.gErrorIgnoreLevel = ROOT.kWarning
@@ -616,6 +617,7 @@ def _fraction_0_1(value: str) -> float:
             sys.exit()
     if HNL or options.RPVSUSY or options.DarkPhoton:
         assert P8gen is not None  # guaranteed by the three branches above
+        P8gen.SetSeed(seed)
         P8gen.SetSmearBeam(options.SmearBeam * u.cm)  # Gaussian beam smearing
         P8gen.SetPaintRadius(options.PaintBeam * u.cm)  # beam painting radius
         P8gen.SetLmin(ship_geo.decayVolume.z0 - ship_geo.target.z0)
@@ -640,6 +642,7 @@ def _fraction_0_1(value: str) -> float:
             )  # Uniform distribution in x/y on the target (0.5 cm of margin at both sides)
             primGen.SmearVertexXY(True)
         P8gen = ROOT.Pythia8Generator()
+        P8gen.SetSeed(seed)
         P8gen.UseExternalFile(inputFile, options.firstEvent)
         # Use geometry constants instead of fragile TGeo navigation
         P8gen.SetTargetCoordinates(ship_geo.target.z0, ship_geo.target.z0 + ship_geo.target.length)
@@ -651,6 +654,7 @@ def _fraction_0_1(value: str) -> float:
 if options.fixedTarget:
     HNL = False
     P8gen = ROOT.FixedTargetGenerator()
+    P8gen.SetSeed(seed)
     P8gen.SetZoffset(options.z_offset * u.mm)
     # Use geometry constants instead of fragile TGeo navigation
     P8gen.SetTargetCoordinates(ship_geo.target.z0, ship_geo.target.z0 + ship_geo.target.length)

pixi.toml

@@ -29,8 +29,6 @@ numpy = "*"
 scipy = "*"
 matplotlib = "*"
 pandas = "*"
-pytest = "*"
-pytest-xdist = "*"
 pyyaml = "*"
 tabulate = "*"
 
@@ -71,7 +69,9 @@ configure = { cmd = """cmake -S . -B build -G Ninja \
     "-DCMAKE_CXX_FLAGS=-isystem $CONDA_PREFIX/include/geant4vmc -isystem $CONDA_PREFIX/include/Geant4" """ }
 build = { cmd = "cmake --build build -j$(nproc)", depends-on = ["configure"] }
 install = { cmd = "cmake --install build", depends-on = ["build"] }
-test = { cmd = "ctest --test-dir build --output-on-failure", depends-on = ["build"] }
+test = { cmd = "ctest --test-dir build --output-on-failure -LE regression", depends-on = ["build"] }
+test-fairship = { cmd = "ctest --test-dir build --output-on-failure --parallel 4 -L regression", depends-on = ["build"] }
+regenerate-fairship-references = { cmd = "tests/fairship_tests/regenerate_references.sh", depends-on = ["build"]  }
 
 # --- CI sim-chain tasks ---
 # Mirror the per-step commands in .github/workflows/build-run.yml so the

shipgen/DPPythia8Generator.cxx

@@ -48,8 +48,9 @@ void DPPythia8Generator::Print() { fPythia->settings.listAll(); };
 
 // -----   Init   ----------------------------------------------------------
 Bool_t DPPythia8Generator::Init() {
-  if (fUseRandom1) fRandomEngine = std::make_shared<PyTr1Rng>();
-  if (fUseRandom3) fRandomEngine = std::make_shared<PyTr3Rng>();
+  const UInt_t seed = fSeed != 0 ? fSeed : gRandom->GetSeed();
+  if (fUseRandom1) fRandomEngine = std::make_shared<PyTr1Rng>(seed);
+  if (fUseRandom3) fRandomEngine = std::make_shared<PyTr3Rng>(seed);
   fPythia->setRndmEnginePtr(fRandomEngine);
   // fPythiaHadDecay->setRndmEnginePtr(fRandomEngine);
   fn = 0;

shipgen/DPPythia8Generator.h

@@ -57,6 +57,7 @@ class DPPythia8Generator : public SHiP::Generator {
   void SetMom(Double_t mom) { fMom = mom; };
   Double_t GetMom() { return fMom; };
   void SetId(Double_t id) { fId = id; };
+  void SetSeed(UInt_t seed) { fSeed = seed; };
   void SetDPId(Int_t id) { fDP = id; };
   Int_t GetDPId() { return fDP; };
   void SetLmin(Double_t z) { fLmin = z; };
@@ -98,6 +99,7 @@ class DPPythia8Generator : public SHiP::Generator {
   Int_t fId;                   // target type
   Bool_t fUseRandom1{kFALSE};  // flag to use TRandom1
   Bool_t fUseRandom3{kTRUE};   // flag to use TRandom3 (default)
+  UInt_t fSeed{0};             // explicit RNG seed; 0 uses gRandom's seed
   Bool_t
       fpbrem;  // flag to do proton bremstrahlung production (default is false)
   TH2F* fpbremPDF;   // pointer to TH2 containing PDF(p,theta) to have a dark

shipgen/FixedTargetGenerator.cxx

@@ -174,8 +174,10 @@ Bool_t FixedTargetGenerator::Init() {
     LOG(error) << "Option not known " << Option.Data() << ", abort";
     return kFALSE;
   }
-  if (fUseRandom1) fRandomEngine = std::make_shared<PyTr1Rng>();
-  if (fUseRandom3) fRandomEngine = std::make_shared<PyTr3Rng>();
+  const UInt_t seed =
+      fSeed != 0 ? static_cast<UInt_t>(fSeed) : gRandom->GetSeed();
+  if (fUseRandom1) fRandomEngine = std::make_shared<PyTr1Rng>(seed);
+  if (fUseRandom3) fRandomEngine = std::make_shared<PyTr3Rng>(seed);
   std::vector<int> r = {221, 221, 223, 223, 113, 331, 333};
   std::vector<int> c = {6, 7, 5, 7, 5, 6, 9};  // decay channel mumu mumuX
 

shipgen/HNLPythia8Generator.cxx

@@ -41,8 +41,9 @@ Bool_t HNLPythia8Generator::Init() {
   if (debug) {
     List(9900015);
   }
-  if (fUseRandom1) fRandomEngine = std::make_shared<PyTr1Rng>();
-  if (fUseRandom3) fRandomEngine = std::make_shared<PyTr3Rng>();
+  const UInt_t seed = fSeed != 0 ? fSeed : gRandom->GetSeed();
+  if (fUseRandom1) fRandomEngine = std::make_shared<PyTr1Rng>(seed);
+  if (fUseRandom3) fRandomEngine = std::make_shared<PyTr3Rng>(seed);
   fPythia->setRndmEnginePtr(fRandomEngine);
   fn = 0;
   if (fextFile) {