fix: Fixing last TCK issues (#795)

Fixes #791 🦕

---------

Signed-off-by: Emmanuel Hugonnet <ehugonne@redhat.com>

Author: ehsavoie

extras/http-client-vertx/src/main/java/org/a2aproject/sdk/client/http/VertxA2AHttpClient.java

@@ -25,7 +25,7 @@ public void testVertxParameterConstructor() {
 
     @Test
     public void testVertxParameterConstructorNullThrows() {
-        assertThrows(NullPointerException.class, () -> {
+        assertThrows(IllegalArgumentException.class, () -> {
             new VertxA2AHttpClient(null);
         });
     }

extras/http-client-vertx/src/test/java/org/a2aproject/sdk/client/http/VertxA2AHttpClientTest.java

@@ -43,6 +43,7 @@
 import jakarta.enterprise.inject.Any;
 import jakarta.inject.Inject;
 import java.util.concurrent.Flow;
+import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -455,7 +456,12 @@ public void onDeleteTaskPushNotificationConfig(DeleteTaskPushNotificationConfigP
             span.end();
         }
     }
-    
+
+    @Override
+    public void validateRequestedTask(@Nullable String requestedTaskId) throws A2AError {
+        delegate.validateRequestedTask(requestedTaskId);
+    }
+
     private boolean extractRequest() {
         return Boolean.getBoolean(EXTRACT_REQUEST_SYS_PROPERTY);
     }

extras/opentelemetry/server/src/main/java/org/a2aproject/sdk/extras/opentelemetry/OpenTelemetryRequestHandlerDecorator.java

@@ -142,6 +142,8 @@ protected CompletableFuture<Void> asyncRequest(
             Flow.Subscriber<String> subscriber = new Flow.Subscriber<String>() {
                 private Flow.@Nullable Subscription subscription;
                 private volatile boolean errorRaised = false;
+                private boolean isSseStream = false;
+                private boolean firstMeaningfulLineSeen = false;
 
                 @Override
                 public void onSubscribe(Flow.Subscription subscription) {
@@ -151,10 +153,23 @@ public void onSubscribe(Flow.Subscription subscription) {
 
                 @Override
                 public void onNext(String item) {
-                    // SSE messages sometimes start with "data:". Strip that off
-                    if (item != null && item.startsWith("data:")) {
-                        item = item.substring(5).trim();
-                        if (!item.isEmpty()) {
+                    if (item != null && !item.isEmpty()) {
+                        if (!firstMeaningfulLineSeen) {
+                            firstMeaningfulLineSeen = true;
+                            isSseStream = item.startsWith("data:") || item.startsWith(":")
+                                    || item.startsWith("event:") || item.startsWith("id:")
+                                    || item.startsWith("retry:");
+                        }
+                        if (isSseStream) {
+                            if (item.startsWith("data:")) {
+                                String data = item.substring(5).trim();
+                                if (!data.isEmpty()) {
+                                    messageConsumer.accept(data);
+                                }
+                            }
+                            // Other SSE control lines (event:, id:, retry:, :) are ignored
+                        } else {
+                            // Plain error body: deliver so SSEEventListener can parse the typed error
                             messageConsumer.accept(item);
                         }
                     }
@@ -300,7 +315,6 @@ private HttpRequest.Builder createRequestBuilder(boolean SSE) throws IOException
         @Override
         public A2AHttpResponse post() throws IOException, InterruptedException {
             HttpRequest request = createRequestBuilder(false)
-                    .POST(HttpRequest.BodyPublishers.ofString(body, StandardCharsets.UTF_8))
                     .build();
             HttpResponse<String> response =
                     httpClient.send(request, BodyHandlers.ofString(StandardCharsets.UTF_8));

http-client/src/main/java/org/a2aproject/sdk/client/http/JdkA2AHttpClient.java

@@ -438,7 +438,12 @@ private A2AResponse<?> processNonStreamingRequest(NonStreamingJSONRPCRequest<?>
      * @return a Multi stream of JSON-RPC responses
      */
     private Multi<? extends A2AResponse<?>> processStreamingRequest(
-            A2ARequest<?> request, ServerCallContext context) {
+            A2ARequest<?> request, ServerCallContext context) throws A2AError {
+        if (request instanceof SendStreamingMessageRequest req) {
+            jsonRpcHandler.validateRequestedTask(req.getParams().message().taskId());
+        } else if (request instanceof SubscribeToTaskRequest req) {
+            jsonRpcHandler.validateRequestedTask(req.getParams().id());
+        }
         try {
             Flow.Publisher<? extends A2AResponse<?>> publisher;
             if (request instanceof SendStreamingMessageRequest req) {
@@ -450,8 +455,6 @@ private Multi<? extends A2AResponse<?>> processStreamingRequest(
             }
             return Multi.createFrom().publisher(publisher);
         } catch (A2AError error) {
-            // For streaming endpoints, wrap immediate errors (like TaskNotFoundError,
-            // UnsupportedOperationError) in error response and send as first SSE event
             return Multi.createFrom().item(generateErrorResponse(request, error));
         }
     }
@@ -601,7 +604,7 @@ private String extractTenant(RoutingContext rc) {
      *   "error": {
      *     "code": -32602,
      *     "message": "Invalid params",
-     *     "details": { ... }
+     *     "data": [ ... ]
      *   }
      * }
      * }</pre>

reference/jsonrpc/src/main/java/org/a2aproject/sdk/server/apps/quarkus/A2AServerRoutes.java

@@ -339,7 +339,7 @@ public ListTasksResult onListTasks(ListTasksParams params, ServerCallContext con
             Instant now = Instant.now();
             if (params.statusTimestampAfter().isAfter(now)) {
                 Map<String, Object> errorData = new HashMap<>();
-                errorData.put("parameter", "lastUpdatedAfter");
+                errorData.put("parameter", "statusTimestampAfter");
                 errorData.put("reason", "Timestamp cannot be in the future");
                 throw new InvalidParamsError(null, "Invalid params", errorData);
             }
@@ -1061,6 +1061,23 @@ private MessageSendSetup initMessageSend(MessageSendParams params, ServerCallCon
         return new MessageSendSetup(taskManager, task, requestContext);
     }
 
+    @Override
+    public void validateRequestedTask(@Nullable String requestedTaskId) throws A2AError {
+        if (requestedTaskId == null) {
+            return;
+        }
+        Task task = taskStore.get(requestedTaskId);
+        if (task == null) {
+            throw new TaskNotFoundError();
+        }
+
+        if (task.status().state().isFinal()) {
+            throw new UnsupportedOperationError(null, String.format(
+                    "Cannot send message to task %s: task is in terminal state %s and cannot accept further messages",
+                    task.id(), task.status().state()), null);
+        }
+    }
+
     private @Nullable Task validateRequestedTask(MessageSendParams params) throws A2AError {
         String requestedTaskId = params.message().taskId();
         if (requestedTaskId == null) {
@@ -1162,24 +1179,5 @@ private void logThreadStats(String label) {
         THREAD_STATS_LOGGER.debug("=== END THREAD STATS ===");
     }
 
-    /**
-     * Check if an event represents a final task state.
-     *
-     * @param eventKind the event to check
-     * @return true if the event represents a final state (COMPLETED, FAILED, CANCELED, REJECTED, UNKNOWN)
-     */
-    private boolean isFinalEvent(EventKind eventKind) {
-        if (!(eventKind instanceof Event event)) {
-            return false;
-        }
-        if (event instanceof Task task) {
-            return task.status() != null && task.status().state() != null
-                    && task.status().state().isFinal();
-        } else if (event instanceof TaskStatusUpdateEvent statusUpdate) {
-            return statusUpdate.isFinal();
-        }
-        return false;
-    }
-
     private record MessageSendSetup(TaskManager taskManager, @Nullable Task task, RequestContext requestContext) {}
 }

server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/DefaultRequestHandler.java

@@ -18,6 +18,7 @@
 import org.a2aproject.sdk.spec.TaskIdParams;
 import org.a2aproject.sdk.spec.TaskPushNotificationConfig;
 import org.a2aproject.sdk.spec.TaskQueryParams;
+import org.jspecify.annotations.Nullable;
 
 public interface RequestHandler {
     Task onGetTask(
@@ -59,4 +60,6 @@ ListTaskPushNotificationConfigsResult onListTaskPushNotificationConfigs(
     void onDeleteTaskPushNotificationConfig(
             DeleteTaskPushNotificationConfigParams params,
             ServerCallContext context) throws A2AError;
+
+    void validateRequestedTask(@Nullable String requestedTaskId) throws A2AError;
 }

server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/RequestHandler.java

@@ -1,12 +1,14 @@
 package org.a2aproject.sdk.grpc.utils;
 
 import org.a2aproject.sdk.spec.A2AErrorCodes;
+
 import static org.a2aproject.sdk.spec.A2AMethods.CANCEL_TASK_METHOD;
 import static org.a2aproject.sdk.spec.A2AMethods.GET_EXTENDED_AGENT_CARD_METHOD;
 import static org.a2aproject.sdk.spec.A2AMethods.SEND_STREAMING_MESSAGE_METHOD;
 
 import java.io.IOException;
 import java.io.StringWriter;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import java.util.logging.Level;
@@ -66,6 +68,7 @@
 import org.a2aproject.sdk.spec.TaskNotFoundError;
 import org.a2aproject.sdk.spec.UnsupportedOperationError;
 import org.a2aproject.sdk.spec.VersionNotSupportedError;
+import org.a2aproject.sdk.util.ErrorDetail;
 import org.a2aproject.sdk.util.Utils;
 import org.jspecify.annotations.Nullable;
 
@@ -284,11 +287,12 @@ public static StreamResponse parseResponseEvent(String body) throws JsonMappingE
         JsonElement jelement = JsonParser.parseString(body);
         JsonObject jsonRpc = jelement.getAsJsonObject();
         String version = getAndValidateJsonrpc(jsonRpc);
-        Object id = getAndValidateId(jsonRpc);
-        JsonElement paramsNode = jsonRpc.get("result");
+        // Check for error before validating id: per JSON-RPC spec, error responses may have null id
         if (jsonRpc.has("error")) {
             throw processError(jsonRpc.getAsJsonObject("error"));
         }
+        Object id = getAndValidateId(jsonRpc);
+        JsonElement paramsNode = jsonRpc.get("result");
         StreamResponse.Builder builder = StreamResponse.newBuilder();
         parseRequestBody(paramsNode, builder, id);
         return builder.build();
@@ -392,8 +396,16 @@ private static A2AError processError(JsonObject error) {
         String message = error.has("message") ? error.get("message").getAsString() : null;
         Integer code = error.has("code") ? error.get("code").getAsInt() : null;
         Map<String, Object> details = null;
-        if (error.has("data") && error.get("data").isJsonObject()) {
-            details =GSON.fromJson(error.get("data"), Map.class);
+        if (error.has("data")) {
+            JsonElement data = error.get("data");
+            if (data.isJsonObject()) {
+                details = GSON.fromJson(data, Map.class);
+            } else if (data.isJsonArray() && !data.getAsJsonArray().isEmpty()) {
+                JsonElement first = data.getAsJsonArray().get(0);
+                if (first.isJsonObject()) {
+                    details = GSON.fromJson(first.getAsJsonObject(), Map.class);
+                }
+            }
         }
         if (code != null) {
             A2AErrorCodes errorCode = A2AErrorCodes.fromCode(code);
@@ -605,10 +617,10 @@ public static String toJsonRPCErrorResponse(Object requestId, A2AError error) {
             output.beginObject();
             output.name("code").value(error.getCode());
             output.name("message").value(error.getMessage());
-            if (!error.getDetails().isEmpty()) {
-                output.name("data");
-                GSON.toJson(error.getDetails(), Map.class, output);
-            }
+            A2AErrorCodes a2aErrorCode = A2AErrorCodes.fromCode(error.getCode());
+            String reason = a2aErrorCode != null ? a2aErrorCode.name() : A2AErrorCodes.INTERNAL.name();
+            output.name("data");
+            GSON.toJson(List.of(ErrorDetail.of(reason, error.getDetails())), List.class, output);
             output.endObject();
             output.endObject();
             return result.toString();