fix: handles integer foreign-key priority (#215)

Author: Zaimwa9

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

@@ -6,4 +6,13 @@
 @Data
 public class FeatureSegmentModel extends BaseModel {
   private Integer priority;
+
+  public FeatureSegmentModel() {
+  }
+
+  // Tolerates the integer foreign-key shape emitted by self-hosted Core/EE
+  // /api/v1/identities/ — Edge emits {"priority": <int>} instead.
+  public FeatureSegmentModel(Integer priority) {
+    this.priority = priority;
+  }
 }

src/test/java/com/flagsmith/flagengine/models/FeatureSegmentModelTest.java

@@ -0,0 +1,58 @@
+package com.flagsmith.flagengine.models;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.flagsmith.MapperFactory;
+import com.flagsmith.models.features.FeatureStateModel;
+import org.junit.jupiter.api.Test;
+
+public class FeatureSegmentModelTest {
+
+  @Test
+  public void deserializesFeatureSegmentAsIntegerForeignKey() throws JsonProcessingException {
+    String json = "{"
+        + "\"feature\": {\"id\": 1, \"name\": \"my_feature\", \"type\": \"STANDARD\"},"
+        + "\"enabled\": true,"
+        + "\"feature_state_value\": \"foo\","
+        + "\"feature_segment\": 321"
+        + "}";
+
+    FeatureStateModel model =
+        MapperFactory.getMapper().readValue(json, FeatureStateModel.class);
+
+    assertThat(model.getFeatureSegment()).isNotNull();
+    assertThat(model.getFeatureSegment().getPriority()).isEqualTo(321);
+  }
+
+  @Test
+  public void deserializesFeatureSegmentAsEngineObject() throws JsonProcessingException {
+    String json = "{"
+        + "\"feature\": {\"id\": 1, \"name\": \"my_feature\", \"type\": \"STANDARD\"},"
+        + "\"enabled\": true,"
+        + "\"feature_state_value\": \"foo\","
+        + "\"feature_segment\": {\"priority\": 5}"
+        + "}";
+
+    FeatureStateModel model =
+        MapperFactory.getMapper().readValue(json, FeatureStateModel.class);
+
+    assertThat(model.getFeatureSegment()).isNotNull();
+    assertThat(model.getFeatureSegment().getPriority()).isEqualTo(5);
+  }
+
+  @Test
+  public void deserializesNullFeatureSegment() throws JsonProcessingException {
+    String json = "{"
+        + "\"feature\": {\"id\": 1, \"name\": \"my_feature\", \"type\": \"STANDARD\"},"
+        + "\"enabled\": true,"
+        + "\"feature_state_value\": \"foo\","
+        + "\"feature_segment\": null"
+        + "}";
+
+    FeatureStateModel model =
+        MapperFactory.getMapper().readValue(json, FeatureStateModel.class);
+
+    assertThat(model.getFeatureSegment()).isNull();
+  }
+}