fix!: Fix cs.Parts .name attribute setting

Setting a name on the `Part` is only allowed during creation. Else this
won't have any effect since its inferred from its `.type`. The user
should be informed about it.

Author: ewuerger

capellambse/model/common/accessors.py

@@ -22,6 +22,7 @@
     "ReferenceSearchingAccessor",
     "ElementListCouplingMixin",
     "RoleTagAccessor",
+    "InvalidChangeRequest",
 ]
 
 import abc
@@ -46,6 +47,10 @@
 _C = t.TypeVar("_C", bound="ElementListCouplingMixin")
 
 
+class InvalidChangeRequest(Exception):
+    """Raised when a change request is invalid."""
+
+
 class NonUniqueMemberError(ValueError):
     """Raised when a duplicate member is inserted into a list."""
 

capellambse/model/common/element.py

@@ -211,17 +211,20 @@ def __init__(
         parent.append(self._element)
         try:
             for key, val in kw.items():
+                prop = getattr(type(self), key)
+                is_acc_or_attr_prop = isinstance(
+                    prop, (accessors.Accessor, properties.AttributeProperty)
+                )
                 if key == "xtype":
                     self._element.set(helpers.ATT_XT, val)
-                elif not isinstance(
-                    getattr(type(self), key),
-                    (accessors.Accessor, properties.AttributeProperty),
+                elif is_acc_or_attr_prop or (
+                    isinstance(prop, property) and not self._constructed
                 ):
+                    setattr(self, key, val)
+                else:
                     raise TypeError(
                         f"Cannot set {key!r} on {type(self).__name__}"
                     )
-                else:
-                    setattr(self, key, val)
             self._model._loader.idcache_index(self._element)
         except BaseException:
             parent.remove(self._element)

capellambse/model/crosslayer/cs.py

@@ -38,10 +38,30 @@ class Part(c.GenericElement):
 
     deployed_parts: c.Accessor
 
-    @property
-    def name(self) -> str:  # type: ignore[override]
+    @property  # type: ignore[override]
+    def name(self) -> str:
+        """Return the name of the Part."""
         return self.type.name
 
+    @name.setter
+    def name(self, value: str) -> None:
+        if not isinstance(value, str):
+            raise TypeError("Name has to be a string")
+
+        if self._constructed:
+            raise c.InvalidChangeRequest(
+                "This won't have any effect. The name is inferred from "
+                "`.type`."
+            )
+
+        if not value:
+            try:
+                del self._element.attrib["name"]
+            except KeyError:
+                pass
+        else:
+            self._element.attrib["name"] = value
+
 
 @c.xtype_handler(None)
 class ExchangeItemAllocation(c.GenericElement):