Fix Dynamic Update Handler return type (#2210)

temporal-sdk/src/main/java/io/temporal/workflow/DynamicUpdateHandler.java

@@ -39,7 +39,7 @@ public interface DynamicUpdateHandler {
 
   default void handleValidate(String updateName, EncodedValues args) {}
 
-  EncodedValues handleExecute(String updateName, EncodedValues args);
+  Object handleExecute(String updateName, EncodedValues args);
 
   /** Returns the actions taken if a workflow exits with a running instance of this handler. */
   default HandlerUnfinishedPolicy getUnfinishedPolicy(String updateName) {

temporal-sdk/src/test/java/io/temporal/workflow/updateTest/DynamicUpdateTest.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2022 Temporal Technologies, Inc. All Rights Reserved.
+ *
+ * Copyright (C) 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this material except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.temporal.workflow.updateTest;
+
+import static org.junit.Assert.assertEquals;
+
+import io.temporal.api.common.v1.WorkflowExecution;
+import io.temporal.client.*;
+import io.temporal.common.converter.EncodedValues;
+import io.temporal.testing.internal.SDKTestOptions;
+import io.temporal.testing.internal.SDKTestWorkflowRule;
+import io.temporal.workflow.CompletablePromise;
+import io.temporal.workflow.DynamicUpdateHandler;
+import io.temporal.workflow.Workflow;
+import io.temporal.workflow.shared.TestWorkflows;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+
+public class DynamicUpdateTest {
+  @Rule
+  public SDKTestWorkflowRule testWorkflowRule =
+      SDKTestWorkflowRule.newBuilder()
+          .setWorkflowTypes(TestDynamicUpdateWorkflowImpl.class)
+          .build();
+
+  @Test
+  public void dynamicUpdate() throws ExecutionException, InterruptedException {
+    String workflowId = UUID.randomUUID().toString();
+    WorkflowClient workflowClient = testWorkflowRule.getWorkflowClient();
+    WorkflowOptions options =
+        SDKTestOptions.newWorkflowOptionsWithTimeouts(testWorkflowRule.getTaskQueue()).toBuilder()
+            .setWorkflowId(workflowId)
+            .build();
+    TestWorkflows.TestWorkflow1 workflow =
+        workflowClient.newWorkflowStub(TestWorkflows.TestWorkflow1.class, options);
+    // To execute workflow client.execute() would do. But we want to start workflow and immediately
+    // return.
+    WorkflowExecution execution = WorkflowClient.start(workflow::execute, "input");
+    WorkflowStub stub = WorkflowStub.fromTyped(workflow);
+
+    assertEquals(
+        "update:update input",
+        stub.startUpdate("update", WorkflowUpdateStage.COMPLETED, String.class, "update input")
+            .getResultAsync()
+            .get());
+
+    Assert.assertThrows(
+        WorkflowUpdateException.class,
+        () ->
+            stub.startUpdate("reject", WorkflowUpdateStage.COMPLETED, String.class, "update input")
+                .getResultAsync());
+
+    stub.startUpdate("complete", WorkflowUpdateStage.COMPLETED, Void.class).getResultAsync().get();
+
+    String result =
+        testWorkflowRule
+            .getWorkflowClient()
+            .newUntypedWorkflowStub(execution, Optional.empty())
+            .getResult(String.class);
+    assertEquals(" update complete", result);
+  }
+
+  public static class TestDynamicUpdateWorkflowImpl implements TestWorkflows.TestWorkflow1 {
+    CompletablePromise<Void> promise = Workflow.newPromise();
+    List<String> updates = new ArrayList<>();
+
+    @Override
+    public String execute(String input) {
+      Workflow.registerListener(
+          new DynamicUpdateHandler() {
+            @Override
+            public void handleValidate(String updateName, EncodedValues args) {
+              if (updateName.equals("reject")) {
+                throw new IllegalArgumentException("simulated failure");
+              }
+            }
+
+            @Override
+            public Object handleExecute(String updateName, EncodedValues args) {
+              updates.add(updateName);
+              if (updateName.equals("complete")) {
+                promise.complete(null);
+                return null;
+              }
+              return "update:" + args.get(0, String.class);
+            }
+          });
+      promise.get();
+      return updates.stream().reduce("", (a, b) -> a + " " + b);
+    }
+  }
+}