fix: issue 226

spec-grpc/src/main/java/io/a2a/grpc/utils/ProtoUtils.java

@@ -3,8 +3,8 @@
 
 import java.nio.charset.StandardCharsets;
 import java.time.Instant;
-import java.time.LocalDateTime;
 import java.time.ZoneOffset;
+import java.time.OffsetDateTime;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -292,7 +292,7 @@ private static io.a2a.grpc.TaskStatus taskStatus(TaskStatus taskStatus) {
                 builder.setUpdate(message(taskStatus.message()));
             }
             if (taskStatus.timestamp() != null) {
-                Instant instant = taskStatus.timestamp().toInstant(ZoneOffset.UTC);
+                Instant instant = taskStatus.timestamp().toInstant();
                 builder.setTimestamp(com.google.protobuf.Timestamp.newBuilder().setSeconds(instant.getEpochSecond()).setNanos(instant.getNano()).build());
             }
             return builder.build();
@@ -889,10 +889,13 @@ private static DataPart dataPart(io.a2a.grpc.DataPart dataPart) {
         }
 
         private static TaskStatus taskStatus(io.a2a.grpc.TaskStatus taskStatus) {
-            return new TaskStatus(
-                    taskState(taskStatus.getState()),
+            TaskState state = taskState(taskStatus.getState());
+            if (state == null) {
+                return null;
+            }
+            return new TaskStatus(state,
                     taskStatus.hasUpdate() ? message(taskStatus.getUpdate()) : null,
-                    LocalDateTime.ofInstant(Instant.ofEpochSecond(taskStatus.getTimestamp().getSeconds(), taskStatus.getTimestamp().getNanos()), ZoneOffset.UTC)
+                    OffsetDateTime.ofInstant(Instant.ofEpochSecond(taskStatus.getTimestamp().getSeconds(), taskStatus.getTimestamp().getNanos()), ZoneOffset.UTC)
             );
         }
 

spec-grpc/src/test/java/io/a2a/grpc/utils/ToProtoTest.java

@@ -22,6 +22,8 @@
 import io.a2a.spec.TaskStatus;
 import io.a2a.spec.TaskStatusUpdateEvent;
 import io.a2a.spec.TextPart;
+
+import java.time.OffsetDateTime;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -269,4 +271,22 @@ public void convertSendMessageConfiguration() {
         assertEquals(1, result.getAcceptedOutputModesCount());
         assertEquals("text", result.getAcceptedOutputModesBytes(0).toStringUtf8());
     }
+
+    @Test
+    public void convertTaskTimestampStatus() {
+        OffsetDateTime expectedTimestamp = OffsetDateTime.parse("2024-10-05T12:34:56Z");
+        TaskStatus testStatus = new TaskStatus(TaskState.COMPLETED, null, expectedTimestamp);
+        Task task = new Task.Builder()
+                .id("task-123")
+                .contextId("context-456")
+                .status(testStatus)
+                .build();
+
+        io.a2a.grpc.Task grpcTask = ProtoUtils.ToProto.task(task);
+        task = ProtoUtils.FromProto.task(grpcTask);
+        TaskStatus status = task.getStatus();
+        assertEquals(TaskState.COMPLETED, status.state());
+        assertNotNull(status.timestamp());
+        assertEquals(expectedTimestamp, status.timestamp());
+    }
 }

spec/src/main/java/io/a2a/spec/TaskStatus.java

@@ -1,6 +1,7 @@
 package io.a2a.spec;
 
-import java.time.LocalDateTime;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@@ -14,14 +15,23 @@
 @JsonInclude(JsonInclude.Include.NON_ABSENT)
 @JsonIgnoreProperties(ignoreUnknown = true)
 public record TaskStatus(TaskState state, Message message,
-                         @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSSSS") LocalDateTime timestamp) {
+                         @JsonFormat(shape = JsonFormat.Shape.STRING) OffsetDateTime timestamp) {
 
     public TaskStatus {
         Assert.checkNotNullParam("state", state);
-        timestamp = timestamp == null ? LocalDateTime.now() : timestamp;
+        timestamp = timestamp == null ? OffsetDateTime.now(ZoneOffset.UTC) : timestamp;
     }
 
     public TaskStatus(TaskState state) {
         this(state, null, null);
     }
+
+    /**
+     * Constructor for testing purposes.
+     * @param state the task state
+     * @param timestamp timestamp generation
+     */
+    TaskStatus(TaskState state, OffsetDateTime timestamp) {
+        this(state, null, timestamp);
+    }
 }

spec/src/test/java/io/a2a/spec/TaskStatusTest.java

@@ -0,0 +1,94 @@
+package io.a2a.spec;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.junit.jupiter.api.Test;
+
+import java.time.OffsetDateTime;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class TaskStatusTest {
+
+    private static final ObjectMapper OBJECT_MAPPER;
+
+    private static final String REPLACE_TIMESTAMP_PATTERN = ".*\"timestamp\":\"([^\"]+)\",?.*";
+
+    static {
+        OBJECT_MAPPER = new ObjectMapper();
+        OBJECT_MAPPER.registerModule(new JavaTimeModule());
+        OBJECT_MAPPER.configure(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE, false);
+    }
+
+    @Test
+    public void testTaskStatusWithSetTimestamp() {
+        TaskState state = TaskState.WORKING;
+        OffsetDateTime offsetDateTime = OffsetDateTime.parse("2023-10-01T12:00:00Z");
+        TaskStatus status = new TaskStatus(state, offsetDateTime);
+
+        assertNotNull(status.timestamp());
+        assertEquals(offsetDateTime, status.timestamp());
+    }
+
+    @Test
+    public void testTaskStatusWithProvidedTimestamp() {
+        OffsetDateTime providedTimestamp = OffsetDateTime.parse("2024-01-01T00:00:00Z");
+        TaskState state = TaskState.COMPLETED;
+        TaskStatus status = new TaskStatus(state, providedTimestamp);
+
+        assertEquals(providedTimestamp, status.timestamp());
+    }
+
+    @Test
+    public void testTaskStatusSerializationUsesISO8601Format() throws Exception {
+        OffsetDateTime expectedTimestamp = OffsetDateTime.parse("2023-10-01T12:00:00.234-05:00");
+        TaskState state = TaskState.WORKING;
+        TaskStatus status = new TaskStatus(state, expectedTimestamp);
+
+        String json = OBJECT_MAPPER.writeValueAsString(status);
+
+        String expectedJson = "{\"state\":\"working\",\"timestamp\":\"2023-10-01T12:00:00.234-05:00\"}";
+        assertEquals(expectedJson, json);
+    }
+
+    @Test
+    public void testTaskStatusDeserializationWithValidISO8601Format() throws Exception {
+        String validJson = "{"
+                + "\"state\": \"auth-required\","
+                + "\"timestamp\": \"2023-10-01T12:00:00.10+03:00\""
+                + "}";
+
+        TaskStatus result = OBJECT_MAPPER.readValue(validJson, TaskStatus.class);
+        assertEquals(TaskState.AUTH_REQUIRED, result.state());
+        assertNotNull(result.timestamp());
+        assertEquals(OffsetDateTime.parse("2023-10-01T12:00:00.100+03:00"), result.timestamp());
+    }
+
+    @Test
+    public void testTaskStatusDeserializationWithInvalidISO8601FormatFails() {
+        String invalidJson = "{"
+                + "\"state\": \"completed\","
+                + "\"timestamp\": \"2023/10/01 12:00:00\""
+                + "}";
+
+        assertThrows(
+                com.fasterxml.jackson.databind.exc.InvalidFormatException.class,
+                () -> OBJECT_MAPPER.readValue(invalidJson, TaskStatus.class)
+        );
+    }
+
+    @Test
+    public void testTaskStatusJsonTimestampMatchesISO8601Regex() throws Exception {
+        TaskState state = TaskState.WORKING;
+        OffsetDateTime expectedTimestamp = OffsetDateTime.parse("2023-10-01T12:00:00.234Z");
+        TaskStatus status = new TaskStatus(state, expectedTimestamp);
+
+        String json = OBJECT_MAPPER.writeValueAsString(status);
+
+        String timestampValue = json.replaceAll(REPLACE_TIMESTAMP_PATTERN, "$1");
+        assertEquals(expectedTimestamp, OffsetDateTime.parse(timestampValue));
+    }
+}