Add tests for DiscreteFunctionIntegrator (globally)

Also fixed a type conversion error

src/scheme/DiscreteFunctionIntegrator.cpp

@@ -73,26 +73,12 @@ DiscreteFunctionIntegrator::_integrateGlobally() const
   using MeshType       = Mesh<Connectivity<Dimension>>;
   std::shared_ptr mesh = std::dynamic_pointer_cast<const MeshType>(m_mesh);
 
-  if constexpr (std::is_same_v<DataType, ValueType>) {
+  static_assert(std::is_convertible_v<DataType, ValueType>);
+
   return std::make_shared<
     DiscreteFunctionP0<Dimension, ValueType>>(mesh,
-                                                IntegrateCellValue<DataType(TinyVector<Dimension>)>::template integrate<
+                                              IntegrateCellValue<ValueType(TinyVector<Dimension>)>::template integrate<
                                                 MeshType>(m_function_id, *m_quadrature_descriptor, *mesh));
-  } else {
-    static_assert(std::is_convertible_v<DataType, ValueType>);
-
-    CellValue<DataType> cell_data =
-      IntegrateCellValue<DataType(TinyVector<Dimension>)>::template integrate<MeshType>(m_function_id,
-                                                                                        *m_quadrature_descriptor,
-                                                                                        *mesh);
-
-    CellValue<ValueType> cell_value{mesh->connectivity()};
-
-    parallel_for(
-      mesh->numberOfCells(), PUGS_LAMBDA(const CellId cell_id) { cell_value[cell_id] = cell_data[cell_id]; });
-
-    return std::make_shared<DiscreteFunctionP0<Dimension, ValueType>>(mesh, cell_value);
-  }
 }
 
 template <size_t Dimension, typename DataType, typename ValueType>

tests/CMakeLists.txt

@@ -157,6 +157,7 @@ add_executable (unit_tests
 add_executable (mpi_unit_tests
   mpi_test_main.cpp
   test_Connectivity.cpp
+  test_DiscreteFunctionIntegrator.cpp
   test_DiscreteFunctionInterpoler.cpp
   test_DiscreteFunctionInterpolerByZone.cpp
   test_DiscreteFunctionP0.cpp