make Component.remap_layers safe

Former-commit-id: dd80ff1 [formerly 051d74e]
Former-commit-id: c922bd4db2d47a49f4bc8bad406bd8a69ff5d1c2

gdsfactory/component.py

@@ -2071,17 +2071,18 @@ def get_info(self):
     def remap_layers(
         self, layermap, include_labels: bool = True, include_paths: bool = True
     ) -> Component:
-        """Moves all polygons in the Component from one layer to another according to the layermap argument.
+        """Returns a copy of the component with remapped layers.
 
         Args:
             layermap: Dictionary of values in format {layer_from : layer_to}.
             include_labels: Selects whether to move Labels along with polygons.
             include_paths: Selects whether to move Paths along with polygons.
         """
+        component = self.copy()
         layermap = {_parse_layer(k): _parse_layer(v) for k, v in layermap.items()}
 
-        all_D = list(self.get_dependencies(True))
-        all_D.append(self)
+        all_D = list(component.get_dependencies(True))
+        all_D.append(component)
         for D in all_D:
             for p in D.polygons:
                 layer = (p.layer, p.datatype)
@@ -2112,7 +2113,7 @@ def remap_layers(
                             new_datatypes[layer_number] = new_layer[1]
                     path.set_layers(*new_layers)
                     path.set_datatypes(*new_datatypes)
-        return self
+        return component
 
 
 def copy(

tests/test_remap.py

@@ -9,11 +9,12 @@ def test_remap_layers():
     c2 = c.remap_layers({gf.LAYER.WG: gf.LAYER.WGN, gf.LAYER.PORT: gf.LAYER.PORTE})
 
     assert len(c.polygons) == 1, len(c.polygons)
-    assert len(c2.polygons) == 0, len(c2.polygons)
+    assert len(c2.polygons) == 1, len(c2.polygons)
     assert len(c.paths) == 2, len(c.paths)
     assert len(c2.paths) == 2, len(c2.paths)
-    assert gf.LAYER.WGCLAD in c.layers
-    assert gf.LAYER.PORT in c2.layers
+    assert gf.LAYER.WG in c.layers
+    assert gf.LAYER.WGN in c2.layers
+    assert gf.LAYER.PORTE in c2.layers
     return c2
 
 
@@ -22,6 +23,5 @@ def test_remap_layers():
     # c.show()
 
     c = gf.components.straight(length=1, width=0.5, add_pins=add_pins_siepic)
-    # c2 = c.remap_layers({gf.LAYER.WG: gf.LAYER.WGN})
     c2 = c.remap_layers({gf.LAYER.WG: gf.LAYER.WGN, gf.LAYER.PORT: gf.LAYER.PORTE})
     c2.show()