fix: Raise InconclusiveMatchError for missing group type mapping

When group_type_mapping is missing, the system should fall back to
/decide/ endpoint rather than returning False. This matches the
behavior of the original _compute_flag_locally method.

Author: haacked

posthog/client.py

@@ -1205,12 +1205,12 @@ def _compute_flag_locally(
                 self.log.warning(
                     f"[FEATURE FLAGS] Unknown group type index {aggregation_group_type_index} for feature flag {feature_flag['key']}"
                 )
-                # failover to `/decide/`
+                # failover to `/flags/`
                 raise InconclusiveMatchError("Flag has unknown group type index")
 
             if group_name not in groups:
                 # Group flags are never enabled in `groups` aren't passed in
-                # don't failover to `/decide/`, since response will be the same
+                # don't failover to `/flags/`, since response will be the same
                 if warn_on_unknown_groups:
                     self.log.warning(
                         f"[FEATURE FLAGS] Can't compute group feature flag: {feature_flag['key']} without group names passed in"

posthog/dependency_graph.py

@@ -433,8 +433,13 @@ def evaluate_flags_with_dependencies(
                 _group_type_mapping = group_type_mapping or {}
 
                 group_name = _group_type_mapping.get(str(aggregation_group_type_index))
-                if not group_name or group_name not in _groups:
-                    # Can't evaluate group flag without proper group info
+                if not group_name:
+                    # Unknown group type index, failover to /flags/
+                    raise InconclusiveMatchError("Flag has unknown group type index")
+
+                if group_name not in _groups:
+                    # Group flags are never enabled if groups aren't passed in
+                    # Don't failover to /flags/, since response will be the same
                     results[flag_key] = False
                     dependency_graph.cache_result(flag_key, False)
                     continue

posthog/test/test_feature_flags.py

@@ -215,7 +215,7 @@ def test_flag_group_properties(self, patch_get, patch_flags):
         )
         self.assertEqual(patch_flags.call_count, 0)
 
-        # Now group type mappings are gone, so fall back to /decide/
+        # Now group type mappings are gone, so fall back to /flags/
         patch_flags.return_value = {
             "featureFlags": {"group-flag": "decide-fallback-value"}
         }