Fix unhashable list

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pysdmx"
-version = "1.0.0-beta-5"
+version = "1.0.0-beta-6"
 description = "Your opinionated Python SDMX library"
 authors = [
     "Xavier Sosnovsky <xavier.sosnovsky@bis.org>",

src/pysdmx/__init__.py

@@ -1,3 +1,3 @@
 """Your opinionated Python SDMX library."""
 
-__version__ = "1.0.0-beta-5"
+__version__ = "1.0.0-beta-6"

src/pysdmx/model/code.py

@@ -17,7 +17,7 @@
 """
 
 from datetime import datetime
-from typing import FrozenSet, Iterator, Optional, Sequence
+from typing import Iterator, Optional, Sequence
 
 from msgspec import Struct
 
@@ -211,17 +211,21 @@ def __extract_code(
         return None
 
     def __by_id(
-        self, id: str, codes: Sequence[HierarchicalCode]
-    ) -> FrozenSet[HierarchicalCode]:
-        out = []
+        self,
+        id: str,
+        codes: Sequence[HierarchicalCode],
+        out: Optional[Sequence[HierarchicalCode]] = None,
+    ) -> Sequence[HierarchicalCode]:
+        if out is None:
+            out = []
         for i in codes:
-            if i.id == id:
-                out.append(i)
+            if i.id == id and i not in out:
+                out.append(i)  # type: ignore[attr-defined]
             if i.codes:
-                out.extend(self.__by_id(id, i.codes))
-        return frozenset(out)
+                self.__by_id(id, i.codes, out)
+        return out
 
-    def by_id(self, id: str) -> FrozenSet[HierarchicalCode]:
+    def by_id(self, id: str) -> Sequence[HierarchicalCode]:
         """Get a code without knowing its parent IDs.
 
         Codes in a hierarchy can be retrieved using their full ID,

tests/model/test_hierarchy.py

@@ -138,7 +138,7 @@ def test_codes_by_id_is_a_set(id, name, agency):
     assert m[0] == grandchild1
 
 
-def test_codes_by_id_dff_names(id, name, agency):
+def test_codes_by_id_diff_names(id, name, agency):
     grandchild1 = HierarchicalCode("child211", "Child 2.1.1")
     grandchild2 = HierarchicalCode("child212", "Child 2.1.2")
     grandchild3 = HierarchicalCode("child211", "Child 2.1.1 - Diff name")