(de)serialize - handle args being complex

As this can happen when the RunReport has been through (de)serialization
a few times.

Author: Hamish Downer

src/sortition_algorithms/utils.py

@@ -117,15 +117,15 @@ def _unstructure_exception(exc: Exception) -> dict[str, Any]:
     """Unstructure hook for exceptions - store type and args"""
     result: dict[str, Any] = {
         "type": f"{exc.__class__.__module__}.{exc.__class__.__name__}",
-        "args": exc.args,
+        "args": _converter.unstructure(exc.args),
     }
     # Special handling for SelectionMultilineError which has custom attributes
     if hasattr(exc, "all_lines"):
         result["all_lines"] = exc.all_lines
     if hasattr(exc, "all_errors"):
         result["all_errors"] = _converter.unstructure(exc.all_errors)
+    # this is for InfeasibleQuotasError
     if hasattr(exc, "features"):
-        # Don't serialize features as it's complex and circular
         result["features"] = _converter.unstructure(exc.features)
     return result
 
@@ -153,8 +153,6 @@ def _structure_exception(obj: dict[str, Any], _: Any) -> Exception:
 
         features = _converter.structure(obj.get("features", {}), FeatureCollection)  # type: ignore[type-abstract]
         output = _converter.structure(obj.get("all_lines", ["dummy"]), list[str])[1:]
-        # We can't fully reconstruct this as it needs a FeatureCollection
-        # Just create a basic SelectionMultilineError with the lines if available
         return errors.InfeasibleQuotasError(features=features, output=output)
     elif exc_type_name.startswith("sortition_algorithms.errors."):
         # For other custom errors, try to find the class

tests/test_utils.py

@@ -520,7 +520,11 @@ def test_run_report_with_infeasible_quotas_error_serialisation(self):
         features = CaseInsensitiveDict()
         features["feat1"] = CaseInsensitiveDict()
         features["feat1"]["value1"] = FeatureValueMinMax(min=2, max=4)
-        report.add_error(InfeasibleQuotasError(features=features, output=["line1", "line2"]))
+        msgs = ["line1", "line2"]
+        iq_error = InfeasibleQuotasError(features=features, output=msgs)
+        # with round trips we can end up with the args being set to include features
+        iq_error.args = (features, ["intro", *msgs])
+        report.add_error(iq_error)
         serialised_form = report.serialize()
         assert "_data" in serialised_form
         assert len(serialised_form["_data"]) == 1
@@ -532,7 +536,11 @@ def test_run_report_with_infeasible_quotas_error_deserialisation(self):
         features = CaseInsensitiveDict()
         features["feat1"] = CaseInsensitiveDict()
         features["feat1"]["value1"] = FeatureValueMinMax(min=2, max=4)
-        report.add_error(InfeasibleQuotasError(features=features, output=["line1", "line2"]))
+        msgs = ["line1", "line2"]
+        iq_error = InfeasibleQuotasError(features=features, output=msgs)
+        # with round trips we can end up with the args being set to include features
+        iq_error.args = (features, ["intro", *msgs])
+        report.add_error(iq_error)
         serialised_form = report.serialize()
         json_report = json.dumps(serialised_form)
         from_json = json.loads(json_report)