fix: Preserve native types for multivariate feature option values

src/main/java/com/flagsmith/models/features/MultivariateFeatureOptionModel.java

@@ -5,5 +5,5 @@
 
 @Data
 public class MultivariateFeatureOptionModel extends BaseModel {
-  private String value;
+  private Object value;
 }

src/test/java/com/flagsmith/flagengine/unit/mappers/EngineMappersTest.java

@@ -1,20 +1,28 @@
 package com.flagsmith.flagengine.unit.mappers;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.flagsmith.MapperFactory;
+import com.flagsmith.flagengine.EvaluationContext;
+import com.flagsmith.flagengine.FeatureContext;
+import com.flagsmith.flagengine.FeatureValue;
+import com.flagsmith.flagengine.Traits;
 import com.flagsmith.mappers.EngineMappers;
 import com.flagsmith.models.TraitConfig;
+import com.flagsmith.models.environments.EnvironmentModel;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
 
+import java.util.List;
 import java.util.Map;
 import java.util.stream.Stream;
 
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
 import com.flagsmith.FlagsmithTestHelper;
-import com.flagsmith.flagengine.EvaluationContext;
-import com.flagsmith.flagengine.Traits;
 
 public class EngineMappersTest {
   private static Stream<Arguments> expectedTraitMaps() {
@@ -49,4 +57,85 @@ public void testMapContextAndIdentityDataToContext_returnsExpectedContext(
       expectedTraits.getAdditionalProperties(),
       mappedContext.getIdentity().getTraits().getAdditionalProperties());
   }
+
+  @Test
+  public void testMapEnvironmentToContext_preservesMultivariateValueTypes()
+      throws JsonProcessingException {
+    String environmentJson = "{\n"
+        + "  \"api_key\": \"test-key\",\n"
+        + "  \"name\": \"Test\",\n"
+        + "  \"project\": {\n"
+        + "    \"name\": \"Test project\",\n"
+        + "    \"organisation\": {\n"
+        + "      \"feature_analytics\": false,\n"
+        + "      \"name\": \"Test Org\",\n"
+        + "      \"id\": 1,\n"
+        + "      \"persist_trait_data\": true,\n"
+        + "      \"stop_serving_flags\": false\n"
+        + "    },\n"
+        + "    \"id\": 1,\n"
+        + "    \"hide_disabled_flags\": false,\n"
+        + "    \"segments\": []\n"
+        + "  },\n"
+        + "  \"segment_overrides\": [],\n"
+        + "  \"id\": 1,\n"
+        + "  \"feature_states\": [\n"
+        + "    {\n"
+        + "      \"feature_state_value\": true,\n"
+        + "      \"django_id\": 1,\n"
+        + "      \"featurestate_uuid\": \"40eb539d-3713-4720-bbd4-829dbef10d51\",\n"
+        + "      \"feature\": { \"name\": \"mv_feature\", \"type\": \"MULTIVARIATE\", \"id\": 1 },\n"
+        + "      \"enabled\": true,\n"
+        + "      \"multivariate_feature_state_values\": [\n"
+        + "        {\n"
+        + "          \"id\": 1,\n"
+        + "          \"multivariate_feature_option\": { \"value\": false },\n"
+        + "          \"percentage_allocation\": 50.0,\n"
+        + "          \"mv_fs_value_uuid\": \"808cba14-03ca-4835-a7f7-58387f01f87d\"\n"
+        + "        },\n"
+        + "        {\n"
+        + "          \"id\": 2,\n"
+        + "          \"multivariate_feature_option\": { \"value\": 42 },\n"
+        + "          \"percentage_allocation\": 30.0,\n"
+        + "          \"mv_fs_value_uuid\": \"918dbb25-14db-4946-b8a8-69488f02f98e\"\n"
+        + "        },\n"
+        + "        {\n"
+        + "          \"id\": 3,\n"
+        + "          \"multivariate_feature_option\": { \"value\": \"a string\" },\n"
+        + "          \"percentage_allocation\": 20.0,\n"
+        + "          \"mv_fs_value_uuid\": \"a29eca36-25dc-5057-c9b9-7a599f13g09f\"\n"
+        + "        }\n"
+        + "      ]\n"
+        + "    }\n"
+        + "  ],\n"
+        + "  \"identity_overrides\": []\n"
+        + "}";
+
+    EnvironmentModel env = MapperFactory.getMapper()
+        .readValue(environmentJson, EnvironmentModel.class);
+
+    EvaluationContext context = EngineMappers.mapEnvironmentToContext(env);
+
+    FeatureContext feature = (FeatureContext) context.getFeatures()
+        .getAdditionalProperties().get("mv_feature");
+    List<FeatureValue> variants = feature.getVariants();
+
+    assertEquals(3, variants.size());
+
+    assertInstanceOf(Boolean.class, feature.getValue(),
+        "Control value should be Boolean, not " + feature.getValue().getClass().getName());
+    assertEquals(true, feature.getValue());
+
+    assertInstanceOf(Boolean.class, variants.get(0).getValue(),
+        "Boolean variant value should be Boolean, not " + variants.get(0).getValue().getClass().getName());
+    assertEquals(false, variants.get(0).getValue());
+
+    assertInstanceOf(Integer.class, variants.get(1).getValue(),
+        "Integer variant value should be Integer, not " + variants.get(1).getValue().getClass().getName());
+    assertEquals(42, variants.get(1).getValue());
+
+    assertInstanceOf(String.class, variants.get(2).getValue(),
+        "String variant value should be String, not " + variants.get(2).getValue().getClass().getName());
+    assertEquals("a string", variants.get(2).getValue());
+  }
 }