fix(multivariate): persist variant key in DynamoDB environment document (#7915)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: gagantrivedi

api/pyproject.toml

@@ -74,7 +74,7 @@ dependencies = [
     "hubspot-api-client>=12.0.0,<13.0.0",
     "djangorestframework-dataclasses>=1.3.1,<2.0.0",
     "pyotp>=2.9.0,<3.0.0",
-    "flagsmith-common[common-core,flagsmith-schemas,task-processor]>=3.9.1,<4",
+    "flagsmith-common[common-core,flagsmith-schemas,task-processor]>=3.10.1,<4",
     "django-stubs>=5.1.3,<6.0.0",
     "tzdata>=2024.1,<2025.0.0",
     "djangorestframework-simplejwt>=5.5.1,<6.0.0",

api/tests/unit/util/mappers/test_unit_mappers_dynamodb.py

@@ -16,7 +16,7 @@
     from environments.identities.models import Identity
     from environments.identities.traits.models import Trait
     from environments.models import Environment, EnvironmentAPIKey
-    from features.models import FeatureState
+    from features.models import Feature, FeatureState
 
 
 def test_map_environment_to_environment_document__valid_environment__returns_expected_document(
@@ -263,6 +263,32 @@ def test_map_environment_to_compressed_environment_document__valid_environment__
     )
 
 
+def test_map_environment_to_compressed_environment_document__mv_option_with_key__key_preserved(
+    environment: "Environment",
+    multivariate_feature: "Feature",
+) -> None:
+    # Given
+    mv_option = multivariate_feature.multivariate_options.first()
+    assert mv_option is not None
+    mv_option.key = "control"
+    mv_option.save()
+
+    # When
+    result = dynamodb.map_environment_to_compressed_environment_document(environment)
+
+    # Then
+    feature_states = json.loads(
+        gzip.decompress(result.document["feature_states"]).decode("utf-8")
+    )
+    mv_options = [
+        mv_value["multivariate_feature_option"]
+        for feature_state in feature_states
+        for mv_value in feature_state["multivariate_feature_state_values"]
+    ]
+    keyed_option = next(option for option in mv_options if option["id"] == mv_option.id)
+    assert keyed_option["key"] == "control"
+
+
 def test_map_environment_to_compressed_environment_v2_document__valid_environment__returns_compressed_fields(
     environment: "Environment",
     feature_state: "FeatureState",