docs(tests/meshIO): added comments to meshIO tests

tests/meshIO/meshIOTest.cpp

@@ -6,6 +6,16 @@
 
 std::string EXAMPLE_FILENAME = std::string(getenv("MESON_SOURCE_ROOT")) + "/src/resources/mesh/sphere.msh";
 
+double ComputeMeshVolume(mfem::Mesh &mesh)
+{
+    double totalVolume = 0.0;
+    for (int i = 0; i < mesh.GetNE(); i++) // Loop over all elements
+    {
+        totalVolume += mesh.GetElementVolume(i);
+    }
+    return totalVolume;
+}
+
 
 class meshIOTest : public ::testing::Test {};
 
@@ -23,4 +33,6 @@ TEST_F(meshIOTest, GetMesh) {
     mfem::Mesh& mesh = meshIO.GetMesh();
     EXPECT_EQ(mesh.GetNE(), 670);
     EXPECT_EQ(mesh.GetNV(), 201);
+    double volume = ComputeMeshVolume(mesh);
+    EXPECT_DOUBLE_EQ(volume, 3.9357596288315868);
 }