fix: hydrate empty Event source via Jackson deserializer

Author: JuroUhlar

.openapi-generator-ignore

@@ -4,6 +4,8 @@ git_push.sh
 api/*
 src/test/java/com/fingerprint/v4/model/*
 src/main/java/com/fingerprint/v4/model/AbstractOpenApiSchema.java
+src/main/java/com/fingerprint/v4/sdk/EventDeserializer.java
+src/main/java/com/fingerprint/v4/sdk/EventMixin.java
 src/main/AndroidManifest.xml
 .github/workflows/maven.yml
 pom.xml

sdk/src/main/java/com/fingerprint/v4/model/Event.java

@@ -24,8 +24,7 @@
     use = JsonTypeInfo.Id.NAME,
     include = JsonTypeInfo.As.PROPERTY,
     property = "source",
-    // SPIKE INTER-2457 option B: missing source hydrates to EventDevice. Never rewrite source:edge.
-    defaultImpl = EventDevice.class,
+    defaultImpl = Event.UnknownEvent.class,
     visible = true)
 @JsonSubTypes({
   @JsonSubTypes.Type(value = EventDevice.class, name = "device"),

sdk/src/main/java/com/fingerprint/v4/sdk/EventDeserializer.java

@@ -0,0 +1,55 @@
+package com.fingerprint.v4.sdk;
+
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.fingerprint.v4.model.Event;
+import com.fingerprint.v4.model.EventDevice;
+import com.fingerprint.v4.model.EventEdge;
+import java.io.IOException;
+
+/**
+ * Treats a missing, null, or empty Event {@code source} as {@code device}.
+ * Unknown non-empty values fail. Never rewrites {@code edge}.
+ */
+public final class EventDeserializer extends JsonDeserializer<Event> {
+  @Override
+  public Event deserialize(JsonParser parser, DeserializationContext context) throws IOException {
+    JsonNode node = parser.getCodec().readTree(parser);
+    if (node == null || !node.isObject()) {
+      throw JsonMappingException.from(parser, "event JSON must be an object");
+    }
+
+    ObjectNode object = (ObjectNode) node;
+    JsonNode source = object.get("source");
+    if (source == null || source.isNull() || (source.isTextual() && source.asText().isEmpty())) {
+      object.put("source", "device");
+      source = object.get("source");
+    }
+
+    if (!source.isTextual()) {
+      throw JsonMappingException.from(parser, "unknown Event source: " + source);
+    }
+
+    String value = source.asText();
+    ObjectMapper implMapper = ((ObjectMapper) parser.getCodec()).copy();
+    implMapper.addMixIn(Event.class, StripEventPolymorphism.class);
+    if ("device".equals(value)) {
+      return implMapper.treeToValue(object, EventDevice.class);
+    }
+    if ("edge".equals(value)) {
+      return implMapper.treeToValue(object, EventEdge.class);
+    }
+    throw JsonMappingException.from(parser, "unknown Event source: " + value);
+  }
+
+  @JsonTypeInfo(use = JsonTypeInfo.Id.NONE)
+  @JsonDeserialize(using = JsonDeserializer.None.class)
+  abstract static class StripEventPolymorphism {}
+}

sdk/src/main/java/com/fingerprint/v4/sdk/EventMixin.java

@@ -0,0 +1,6 @@
+package com.fingerprint.v4.sdk;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+@JsonDeserialize(using = EventDeserializer.class)
+public abstract class EventMixin {}

sdk/src/main/java/com/fingerprint/v4/sdk/JSON.java

@@ -15,7 +15,9 @@
 import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.fingerprint.v4.model.Event;
 import jakarta.ws.rs.core.GenericType;
 import jakarta.ws.rs.ext.ContextResolver;
 import java.text.DateFormat;
@@ -45,6 +47,10 @@ public JSON() {
             .defaultDateFormat(new RFC3339DateFormat())
             .addModule(new JavaTimeModule())
             .addModule(new RFC3339JavaTimeModule())
+            .addModule(
+                new SimpleModule()
+                    .setMixInAnnotation(Event.class, EventMixin.class)
+                    .addDeserializer(Event.class, new EventDeserializer()))
             .build();
   }
 

sdk/src/test/java/com/fingerprint/v4/SerializationTest.java

@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertInstanceOf;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -124,6 +125,29 @@ public void missingSourceHydratesToEventDeviceAndSourceEdgeStaysEventEdge() thro
     assertInstanceOf(EventEdge.class, edge);
   }
 
+  @Test
+  public void emptySourceHydratesToEventDevice() throws IOException {
+    ObjectMapper sdkObjectMapper = JSON.getDefault().getMapper();
+    ObjectNode deviceNode =
+        sdkObjectMapper.readValue(
+            getFileAsIOStream("mocks/events/get_event_200.json"), ObjectNode.class);
+    deviceNode.put("source", "");
+    Event event = sdkObjectMapper.treeToValue(deviceNode, Event.class);
+    assertInstanceOf(EventDevice.class, event);
+  }
+
+  @Test
+  public void unknownSourceFails() throws IOException {
+    ObjectMapper sdkObjectMapper = JSON.getDefault().getMapper();
+    ObjectNode deviceNode =
+        sdkObjectMapper.readValue(
+            getFileAsIOStream("mocks/events/get_event_200.json"), ObjectNode.class);
+    deviceNode.put("source", "webhook");
+    assertThrows(
+        com.fasterxml.jackson.databind.JsonMappingException.class,
+        () -> sdkObjectMapper.treeToValue(deviceNode, Event.class));
+  }
+
   @TestFactory
   public Stream<DynamicTest> deserializeErrorResponses() {
     ObjectMapper sdkObjectMapper = JSON.getDefault().getMapper();

template/libraries/jersey3/JSON.mustache

@@ -5,6 +5,8 @@ package {{invokerPackage}};
 import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fingerprint.v4.model.Event;
 {{#openApiNullable}}
 import org.openapitools.jackson.nullable.JsonNullableModule;
 {{/openApiNullable}}
@@ -44,6 +46,10 @@ public class JSON implements ContextResolver<ObjectMapper> {
             .addModule(new JsonNullableModule())
             {{/openApiNullable}}
             .addModule(new RFC3339JavaTimeModule())
+            .addModule(
+                new SimpleModule()
+                    .setMixInAnnotation(Event.class, EventMixin.class)
+                    .addDeserializer(Event.class, new EventDeserializer()))
             .build();
   }