rewrite to append method and add asserts to test

Signed-off-by: Thijs Baaijen <[email protected]>

Author: Thijss

src/power_grid_model_ds/_core/model/grids/base.py

@@ -441,20 +441,21 @@ def set_feeder_ids(self):
         set_feeder_ids(grid=self)
 
     @classmethod
-    def from_extended(cls, extended: "Grid", load_graphs: bool = True) -> "Grid":
+    def from_extended(cls, extended: "Grid") -> "Grid":
         """Create a grid from an extended Grid object."""
         new_grid = cls.empty()
 
+        # Add nodes first, so that branches can reference them
+        new_grid.append(new_grid.node.__class__.from_extended(extended.node))
+
         for field in dataclasses.fields(cls):
+            if field.name == "node":
+                continue  # already added
             if issubclass(field.type, FancyArray):
                 extended_array = getattr(extended, field.name)
                 new_array = field.type.from_extended(extended_array)
-                setattr(new_grid, field.name, new_array)
-
-        new_grid._id_counter = new_grid.max_id
+                new_grid.append(new_array, check_max_id=False)
 
-        if load_graphs:
-            new_grid.graphs = GraphContainer.from_arrays(new_grid)
         return new_grid
 
 

tests/unit/model/grids/test_grid_base.py

@@ -62,6 +62,9 @@ def test_from_extended_grid():
     assert grid.graphs.active_graph.nr_nodes == len(grid.node)
     assert grid.graphs.complete_graph.nr_nodes == len(grid.branches)
 
+    assert extended_grid.id_counter == grid.id_counter
+    assert extended_grid.max_id == grid.max_id
+
 
 def test_grid_build(basic_grid: Grid):
     grid = basic_grid