feat: Safety checks for CylindricalContainerBuilder BluePrint constru…

…ctor (#2883)

Adding empty builders container and specific binning types safety checks to the BluePrint constructor of the CyllindricalContainerBuilder.

Core/src/Detector/CylindricalContainerBuilder.cpp

@@ -156,7 +156,36 @@ Acts::Experimental::CylindricalContainerBuilder::CylindricalContainerBuilder(
     }
   }
 
+  if (m_cfg.builders.empty()) {
+    throw std::invalid_argument(
+        "CylindricalContainerBuilder: no sub builders provided.");
+  }
   m_cfg.binning = bpNode.binning;
+  // Check if binning value is correctly chosen
+  if (m_cfg.binning.size() == 1u) {
+    // 1-dimensional case
+    auto b = m_cfg.binning.front();
+    if (b != Acts::binR && b != Acts::binZ && b != Acts::binPhi) {
+      throw std::invalid_argument(
+          "CylindricalContainerBuilder: 1D binning only supported in z, r, or "
+          "phi");
+    }
+  } else if (m_cfg.binning.size() == 2u) {
+    // 2-dimensional case, this is for wrapping
+    if (m_cfg.binning !=
+        std::vector<Acts::BinningValue>{Acts::binZ, Acts::binR}) {
+      throw std::invalid_argument(
+          "CylindricalContainerBuilder: 2D binning only supports wrapping in "
+          "z-r.");
+    } else if (m_cfg.builders.size() != 2u) {
+      // Wrapping needs exactly one inner (volume or container) and one outer
+      // volume
+      throw std::invalid_argument(
+          "CylindricalContainerBuilder: 2D wrapping in z-r requires exactly "
+          "two builders.");
+    }
+  }
+
   m_cfg.auxiliary = "*** acts auto-generated from proxy ***";
   m_cfg.geoIdGenerator = bpNode.geoIdGenerator;
   m_cfg.rootVolumeFinderBuilder = bpNode.rootVolumeFinderBuilder;
@@ -205,17 +234,6 @@ Acts::Experimental::CylindricalContainerBuilder::construct(
   }
   ACTS_VERBOSE("Number of root volumes: " << rootVolumes.size());
 
-  // Check if a root volume finder is provided
-  if (m_cfg.rootVolumeFinderBuilder) {
-    // Return the container
-    return Acts::Experimental::DetectorComponent{
-        {},
-        portalContainer,
-        RootDetectorVolumes{
-            rootVolumes,
-            m_cfg.rootVolumeFinderBuilder->construct(gctx, rootVolumes)}};
-  }
-
   // Geometry Id generation
   if (m_cfg.geoIdGenerator != nullptr) {
     ACTS_DEBUG("Assigning geometry ids to the detector");
@@ -244,6 +262,17 @@ Acts::Experimental::CylindricalContainerBuilder::construct(
     }
   }
 
+  // Check if a root volume finder is provided
+  if (m_cfg.rootVolumeFinderBuilder) {
+    // Return the container
+    return Acts::Experimental::DetectorComponent{
+        {},
+        portalContainer,
+        RootDetectorVolumes{
+            rootVolumes,
+            m_cfg.rootVolumeFinderBuilder->construct(gctx, rootVolumes)}};
+  }
+
   // Return the container
   return Acts::Experimental::DetectorComponent{
       {}, portalContainer, RootDetectorVolumes{rootVolumes, tryRootVolumes()}};