Properly handle InfeasibleQuotasError in serialize/deserialize

Author: Hamish Downer

src/sortition_algorithms/features.py

@@ -44,7 +44,7 @@
 MAX_FLEX_UNSET = -1
 
 
-@define(kw_only=True, slots=True)
+@define(kw_only=True, slots=True, eq=True)
 class FeatureValueMinMax:
     min: int
     max: int

src/sortition_algorithms/utils.py

@@ -126,7 +126,7 @@ def _unstructure_exception(exc: Exception) -> dict[str, Any]:
         result["all_errors"] = _converter.unstructure(exc.all_errors)
     if hasattr(exc, "features"):
         # Don't serialize features as it's complex and circular
-        result["has_features"] = True
+        result["features"] = _converter.unstructure(exc.features)
     return result
 
 
@@ -148,9 +148,14 @@ def _structure_exception(obj: dict[str, Any], _: Any) -> Exception:
         )
         return errors.ParseTableMultiError(all_errors)
     elif exc_type_name == "sortition_algorithms.errors.InfeasibleQuotasError":
+        # avoid circular import
+        from sortition_algorithms.features import FeatureCollection
+
+        features = _converter.structure(obj.get("features", {}), FeatureCollection)
+        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.SelectionMultilineError(obj.get("all_lines", obj.get("args", ["Infeasible quotas error"])))
+        return errors.InfeasibleQuotasError(features=features, output=output)
     elif exc_type_name.startswith("sortition_algorithms.errors."):
         # For other custom errors, try to find the class
         class_name = exc_type_name.split(".")[-1]

tests/test_utils.py

@@ -5,7 +5,8 @@
 
 import pytest
 
-from sortition_algorithms.errors import SelectionError, SelectionMultilineError
+from sortition_algorithms.errors import InfeasibleQuotasError, SelectionError, SelectionMultilineError
+from sortition_algorithms.features import FeatureValueMinMax
 from sortition_algorithms.utils import ReportLevel, RunReport, get_cell_name
 
 
@@ -506,6 +507,32 @@ def test_run_report_with_multiline_error_deserialisation(self):
         assert str(deserialised_report.last_error()) == "Error line 1\nError line 2\nError line 3"
         assert isinstance(deserialised_report.last_error(), SelectionMultilineError)
 
+    def test_run_report_with_infeasible_quotas_error_serialisation(self):
+        report = RunReport()
+        report.add_error(
+            InfeasibleQuotasError(
+                features={"feat1": {"value1": FeatureValueMinMax(min=2, max=4)}}, output=["line1", "line2"]
+            )
+        )
+        serialised_form = report.serialize()
+        assert "_data" in serialised_form
+        assert len(serialised_form["_data"]) == 1
+
+    def test_run_report_with_infeasible_quotas_error_deserialisation(self):
+        report = RunReport()
+        error = InfeasibleQuotasError(
+            features={"feat1": {"value1": FeatureValueMinMax(min=2, max=4)}}, output=["line1", "line2"]
+        )
+        report.add_error(error)
+        serialised_form = report.serialize()
+        deserialised_report = RunReport.deserialize(serialised_form)
+
+        # Check the error is preserved with all lines and features
+        deserialised_error = deserialised_report.last_error()
+        assert isinstance(deserialised_error, InfeasibleQuotasError)
+        assert str(deserialised_error) == "The quotas are infeasible:\nline1\nline2"
+        assert deserialised_error.features == {"feat1": {"value1": FeatureValueMinMax(min=2, max=4)}}
+
     def test_run_report_with_mixed_content_serialisation_deserialisation(self):
         """Test round-trip with lines, tables, and errors mixed together"""
         report = RunReport()