Add tests for DiscreteFunctionIntegrator (by zone)

Also fixed a bug related to type conversions

src/scheme/DiscreteFunctionIntegrator.cpp

@@ -46,10 +46,10 @@ DiscreteFunctionIntegrator::_integrateOnZoneList() const
     }
   }
 
-  Array<DataType> array =
-    IntegrateCellValue<DataType(TinyVector<Dimension>)>::template integrate<MeshType>(m_function_id,
-                                                                                      *m_quadrature_descriptor, *p_mesh,
-                                                                                      zone_cell_list);
+  Array<ValueType> array =
+    IntegrateCellValue<ValueType(TinyVector<Dimension>)>::template integrate<MeshType>(m_function_id,
+                                                                                       *m_quadrature_descriptor,
+                                                                                       *p_mesh, zone_cell_list);
 
   CellValue<ValueType> cell_value{p_mesh->connectivity()};
   if constexpr (is_tiny_vector_v<ValueType> or is_tiny_matrix_v<ValueType>) {

tests/CMakeLists.txt

@@ -158,6 +158,7 @@ add_executable (mpi_unit_tests
   mpi_test_main.cpp
   test_Connectivity.cpp
   test_DiscreteFunctionIntegrator.cpp
+  test_DiscreteFunctionIntegratorByZone.cpp
   test_DiscreteFunctionInterpoler.cpp
   test_DiscreteFunctionInterpolerByZone.cpp
   test_DiscreteFunctionP0.cpp