Fix cached version hierarchy comparison

codelists/hierarchy.py

@@ -31,6 +31,21 @@ def __init__(self, root, edges):
         self._descendants_cache = {}
         self._ancestors_cache = {}
 
+    def __eq__(self, other):
+        """Compare hierarchies excluding cache items, resolving possible deserialisation differences"""
+
+        def resolve_deser_nulls(_dict):
+            return {k or "null": {i or "null" for i in v} for k, v in _dict.items()}
+
+        return (
+            self.root == other.root
+            and self.nodes == other.nodes
+            and resolve_deser_nulls(self.child_map)
+            == resolve_deser_nulls(other.child_map)
+            and resolve_deser_nulls(self.parent_map)
+            == resolve_deser_nulls(other.parent_map)
+        )
+
     @classmethod
     def from_codes(cls, coding_system, codes):
         """Build a hierarchy containing the given codes, and their ancestors/descendants

coding_systems/base/import_data_utils.py

@@ -1,4 +1,3 @@
-import json
 import shutil
 from itertools import islice
 from pathlib import Path
@@ -339,11 +338,6 @@ def _check_version_by_hierarchy(coding_system, version):
     and identical hierarchies.
     """
 
-    def _hierarchy_excl_cache_items(hierarchy):
-        # `_descendants_cache` and `_ancestors_cache` will not have been generated for the
-        # new hierarchy
-        return {k: v for k, v in hierarchy.items() if not k.endswith("_cache")}
-
     # All codelist versions that existed prior to implementation of coding system releases
     # have an "unknown" coding system release, which represents the coding system data at that
     # point. For older codelist versions, that is not the actual coding system release that was
@@ -352,13 +346,8 @@ def _hierarchy_excl_cache_items(hierarchy):
     # All existing codelist versions, including those with the "unknown" coding system release,
     # will have a cached hierarchy, built with the original coding system release.
     # We compare this to a hierarchy built from the same codes, but with the new release.
-    original_hierarchy_data = _hierarchy_excl_cache_items(
-        json.loads(version.cached_hierarchy.data)
-    )
-    new_hierarchy_data = _hierarchy_excl_cache_items(
-        json.loads(Hierarchy.from_codes(coding_system, version.codes).data_for_cache())
-    )
-    return original_hierarchy_data == new_hierarchy_data
+
+    return version.hierarchy == Hierarchy.from_codes(coding_system, version.codes)
 
 
 def _check_version_by_search(coding_system, version):

coding_systems/base/tests/test_import_data_utils.py

@@ -1,3 +1,4 @@
+import json
 from datetime import datetime
 
 import pytest
@@ -323,3 +324,46 @@ def test_save_codelist_draft_updates_compatibility_multiple_releases(self):
             self.bnf_version_with_search.compatible_releases.first().database_alias
             == "bnf_import-data_20220901"
         )
+
+
+class TestUpdateCodelistVersionCompatibilityIsOrderInsensitive(
+    BaseCodingSystemDynamicDatabaseTestCase
+):
+    db_aliases = [
+        "bnf_import-data_20221101",
+    ]
+
+    @pytest.mark.usefixtures("_get_bnf_release", "_get_bnf_review_version_with_search")
+    def test_update_codelist_version_compatibility_is_order_insensitive(
+        self,
+    ):
+        # modify the cached hierarchy data such that order of list elements is reversed
+        modified_existing_cached_hierarchy = json.loads(
+            self.bnf_review_version_with_search.cached_hierarchy.data
+        )
+        modified_existing_cached_hierarchy["nodes"] = list(
+            reversed(modified_existing_cached_hierarchy["nodes"])
+        )
+        modified_existing_cached_hierarchy["child_map"] = {
+            k: list(reversed(v))
+            for k, v in modified_existing_cached_hierarchy["child_map"].items()
+        }
+        modified_existing_cached_hierarchy["parent_map"] = {
+            k: list(reversed(v))
+            for k, v in modified_existing_cached_hierarchy["parent_map"].items()
+        }
+        modified_existing_cached_hierarchy_data = json.dumps(
+            modified_existing_cached_hierarchy
+        )
+        assert (
+            modified_existing_cached_hierarchy_data
+            != self.bnf_review_version_with_search.cached_hierarchy.data
+        )
+
+        self.bnf_review_version_with_search.cached_hierarchy.data = (
+            modified_existing_cached_hierarchy_data
+        )
+        self.bnf_review_version_with_search.cached_hierarchy.save()
+
+        update_codelist_version_compatibility("bnf", self.bnf_release.database_alias)
+        assert self.bnf_review_version_with_search.compatible_releases.exists()