fix: merge metadata appendArtifactToTask metadata #615 (#616)

flex-myeonghyeon · mhyeon-lee · web-flow · commit 767ca4348d6c · 2026-02-06T10:38:52.000Z
Co-authored-by: mhyeon-lee &lt;mhyeon.lee@gmail.com&gt;
diff --git a/server-common/src/test/java/io/a2a/server/tasks/TaskManagerTest.java b/server-common/src/test/java/io/a2a/server/tasks/TaskManagerTest.java
@@ -191,6 +191,7 @@ public void testTaskArtifactUpdateEventAppendTrueWithExistingArtifact() throws A
                 .artifactId("artifact-id")
                 .name("artifact-1")
                 .parts(Collections.singletonList(new TextPart("existing content")))
+                .metadata(Map.of("key1", "value1"))
                 .build();
         Task taskWithArtifact = Task.builder(initialTask)
                 .artifacts(Collections.singletonList(existingArtifact))
@@ -202,6 +203,7 @@ public void testTaskArtifactUpdateEventAppendTrueWithExistingArtifact() throws A
                 .artifactId("artifact-id")
                 .name("artifact-1")
                 .parts(Collections.singletonList(new TextPart("new content")))
+                .metadata(Map.of("key2", "value2"))
                 .build();
         TaskArtifactUpdateEvent event = TaskArtifactUpdateEvent.builder()
                 .taskId(minimalTask.id())
@@ -219,6 +221,9 @@ public void testTaskArtifactUpdateEventAppendTrueWithExistingArtifact() throws A
         assertEquals(2, updatedArtifact.parts().size());
         assertEquals("existing content", ((TextPart) updatedArtifact.parts().get(0)).text());
         assertEquals("new content", ((TextPart) updatedArtifact.parts().get(1)).text());
+
+        assertEquals("value1", updatedArtifact.metadata().get("key1"));
+        assertEquals("value2", updatedArtifact.metadata().get("key2"));
     }
 
     @Test
diff --git a/spec/src/main/java/io/a2a/util/Utils.java b/spec/src/main/java/io/a2a/util/Utils.java
@@ -3,7 +3,9 @@
 import static io.a2a.util.Assert.checkNotNullParam;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.logging.Logger;
 
 import com.google.gson.Gson;
@@ -129,8 +131,21 @@ public static Task appendArtifactToTask(Task task, TaskArtifactUpdateEvent event
             log.fine(String.format("Appending parts to artifact id %s for task %s", artifactId, taskId));
             List<Part<?>> parts = new ArrayList<>(existingArtifact.parts());
             parts.addAll(newArtifact.parts());
+
+            Map<String, Object> mergedMetadata = null;
+            if (existingArtifact.metadata() != null || newArtifact.metadata() != null) {
+                mergedMetadata = new HashMap<>();
+                if (existingArtifact.metadata() != null) {
+                    mergedMetadata.putAll(existingArtifact.metadata());
+                }
+                if (newArtifact.metadata() != null) {
+                    mergedMetadata.putAll(newArtifact.metadata());
+                }
+            }
+
             Artifact updated = Artifact.builder(existingArtifact)
                     .parts(parts)
+                    .metadata(mergedMetadata)
                     .build();
             artifacts.set(existingArtifactIndex, updated);
         } else {
