Part/Toponaming: Refactor makeElementCompound

Refactor to address linter issues, breaking up large methods, renaming variables, etc.

tests/src/Mod/Part/App/TopoShapeExpansion.cpp

@@ -4,7 +4,9 @@
 #include "src/App/InitApplication.h"
 #include <Mod/Part/App/TopoShape.h>
 
+#include <BRepAlgoAPI_Fuse.hxx>
 #include <BRepBuilderAPI_MakeEdge.hxx>
+#include <BRepPrimAPI_MakeBox.hxx>
 #include <TopoDS_Edge.hxx>
 #include <BRep_Builder.hxx>
 
@@ -115,4 +117,48 @@ TEST_F(TopoShapeExpansionTest, makeElementCompoundTwoShapesGeneratesMap)
     EXPECT_EQ(4, topoShape.getMappedChildElements().size());  // two vertices and two edges
 }
 
+namespace
+{
+
+std::pair<TopoDS_Shape, TopoDS_Shape> CreateTwoCubes()
+{
+    auto boxMaker1 = BRepPrimAPI_MakeBox(1.0, 1.0, 1.0);
+    boxMaker1.Build();
+    auto box1 = boxMaker1.Shape();
+
+    auto boxMaker2 = BRepPrimAPI_MakeBox(1.0, 1.0, 1.0);
+    boxMaker2.Build();
+    auto box2 = boxMaker2.Shape();
+    auto transform = gp_Trsf();
+    transform.SetTranslation(gp_Pnt(0.0, 0.0, 0.0), gp_Pnt(1.0, 0.0, 0.0));
+    box2.Location(TopLoc_Location(transform));
+
+    return {box1, box2};
+}
+}  // namespace
+
+TEST_F(TopoShapeExpansionTest, makeElementCompoundTwoCubes)
+{
+    // Arrange
+    auto [cube1, cube2] = CreateTwoCubes();
+    Part::TopoShape cube1TS {cube1};
+    cube1TS.Tag = 1;
+    Part::TopoShape cube2TS {cube2};
+    cube2TS.Tag = 2;
+
+    // Act
+    Part::TopoShape topoShape;
+    topoShape.makeElementCompound({cube1TS, cube2TS});
+
+    // Assert
+    auto elementMap = topoShape.getElementMap();
+    EXPECT_EQ(52, elementMap.size());
+    // Two cubes, each consisting of:
+    // 8 Vertices
+    // 12 Edges
+    // 6 Faces
+    // ----------
+    // 26 subshapes each
+}
+
 // NOLINTEND(readability-magic-numbers,cppcoreguidelines-avoid-magic-numbers)