Allow custom task queues in TestWorkflowExtension

CHANGELOG.md

@@ -25,6 +25,8 @@ to docs, or any other relevant information.
   `WorkflowOutboundCallsInterceptorBase` need to add them, and Base subclasses override them to see calls with options.
 
 ### Added
+- `TestWorkflowExtension.Builder.setWorkerTaskQueue` lets tests specify a custom worker task queue.
+  When unset or `null`, the extension continues to generate a task queue name for each test.
 - Applications can use the experimental `@TransferTypeConvertible` annotation and
   `TransferTypeConverter` interface to convert top-level model values to transfer types. The SDK
   applies this conversion to workflow, activity, Nexus, and schedule payloads, including failure

temporal-testing/src/main/java/io/temporal/testing/TestWorkflowExtension.java

@@ -23,6 +23,7 @@
 import java.time.Instant;
 import java.util.*;
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;
 import org.junit.jupiter.api.extension.ExtensionContext;
@@ -79,6 +80,7 @@ private enum ServiceType {
   private static final String NEXUS_ENDPOINT_KEY = "nexusEndpoint";
 
   private final WorkerOptions workerOptions;
+  private final String workerTaskQueue;
   private final WorkflowClientOptions workflowClientOptions;
   private final ActivityClientOptions activityClientOptions;
   private final WorkerFactoryOptions workerFactoryOptions;
@@ -100,6 +102,7 @@ private enum ServiceType {
 
   private TestWorkflowExtension(Builder builder) {
     workerOptions = builder.workerOptions;
+    workerTaskQueue = builder.workerTaskQueue;
     if (builder.workflowClientOptions != null) {
       workflowClientOptions = builder.workflowClientOptions;
     } else {
@@ -214,7 +217,10 @@ public void beforeEach(ExtensionContext context) {
 
     try {
       String taskQueue =
-          String.format("WorkflowTest-%s-%s", context.getDisplayName(), context.getUniqueId());
+          workerTaskQueue != null
+              ? workerTaskQueue
+              : String.format(
+                  "WorkflowTest-%s-%s", context.getDisplayName(), context.getUniqueId());
       String nexusEndpointName = String.format("WorkflowTestNexusEndpoint-%s", UUID.randomUUID());
       boolean createNexusEndpoint =
           !doNotSetupNexusEndpoint && nexusServiceImplementations.length > 0;
@@ -327,6 +333,7 @@ public static class Builder {
     private static final Object[] NO_NEXUS_SERVICES = new Object[0];
 
     private WorkerOptions workerOptions = WorkerOptions.getDefaultInstance();
+    private String workerTaskQueue;
     private WorkflowClientOptions workflowClientOptions;
     private ActivityClientOptions activityClientOptions;
     private WorkerFactoryOptions workerFactoryOptions;
@@ -357,6 +364,25 @@ public Builder setWorkerOptions(WorkerOptions options) {
       return this;
     }
 
+    /**
+     * Sets the task queue used by the worker, injected workflow stubs and {@link WorkflowOptions},
+     * and any automatically created Nexus endpoint. If unset or {@code null}, a task queue name is
+     * generated for each test.
+     *
+     * <p>When using an external service, avoid sharing the same task queue across parallel tests in
+     * the same namespace, as their workers may process each other's tasks.
+     *
+     * @param workerTaskQueue task queue name, or {@code null} to use a generated name.
+     * @throws IllegalArgumentException if the task queue name is empty.
+     */
+    public Builder setWorkerTaskQueue(@Nullable String workerTaskQueue) {
+      if (workerTaskQueue != null && workerTaskQueue.isEmpty()) {
+        throw new IllegalArgumentException("workerTaskQueue should not be an empty string");
+      }
+      this.workerTaskQueue = workerTaskQueue;
+      return this;
+    }
+
     /**
      * Override {@link WorkflowClientOptions} for test environment. If set, takes precedence over
      * {@link #setNamespace(String) namespace}.

temporal-testing/src/test/java/io/temporal/testing/junit5/TestWorkflowExtensionTaskQueueTest.java

@@ -0,0 +1,79 @@
+package io.temporal.testing.junit5;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowOptions;
+import io.temporal.testing.TestWorkflowExtension;
+import io.temporal.testing.junit5.TestWorkflowExtensionTest.HelloActivityImpl;
+import io.temporal.testing.junit5.TestWorkflowExtensionTest.HelloWorkflow;
+import io.temporal.testing.junit5.TestWorkflowExtensionTest.HelloWorkflowImpl;
+import io.temporal.testing.junit5.TestWorkflowExtensionTest.TestNexusServiceImpl;
+import io.temporal.worker.Worker;
+import java.util.concurrent.TimeUnit;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+@Timeout(value = 30, unit = TimeUnit.SECONDS)
+public class TestWorkflowExtensionTaskQueueTest {
+
+  @Test
+  public void rejectsEmptyTaskQueue() {
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> TestWorkflowExtension.newBuilder().setWorkerTaskQueue(""));
+  }
+
+  @Nested
+  class CustomTaskQueue {
+    @RegisterExtension
+    final TestWorkflowExtension extension =
+        TestWorkflowExtension.newBuilder()
+            .setWorkerTaskQueue("expense-category")
+            .registerWorkflowImplementationTypes(HelloWorkflowImpl.class)
+            .setActivityImplementations(new HelloActivityImpl())
+            .setNexusServiceImplementation(new TestNexusServiceImpl())
+            .build();
+
+    @Test
+    void usesCustomTaskQueue(
+        Worker worker,
+        WorkflowOptions options,
+        WorkflowClient client,
+        HelloWorkflow injectedWorkflow) {
+      assertEquals("expense-category", worker.getTaskQueue());
+      assertEquals("expense-category", options.getTaskQueue());
+      assertEquals(
+          "Hello Injected from activity BuildGreeting and workflow HelloWorkflow",
+          injectedWorkflow.sayHello("Injected"));
+
+      HelloWorkflow workflow =
+          client.newWorkflowStub(
+              HelloWorkflow.class,
+              WorkflowOptions.newBuilder().setTaskQueue("expense-category").build());
+      assertEquals(
+          "Hello Client from activity BuildGreeting and workflow HelloWorkflow",
+          workflow.sayHello("Client"));
+    }
+  }
+
+  @Nested
+  class NullTaskQueue {
+    @RegisterExtension
+    final TestWorkflowExtension extension =
+        TestWorkflowExtension.newBuilder()
+            .setWorkerTaskQueue("expense-category")
+            .setWorkerTaskQueue(null)
+            .build();
+
+    @Test
+    void restoresGeneratedTaskQueue(Worker worker, WorkflowOptions options) {
+      assertTrue(worker.getTaskQueue().startsWith("WorkflowTest-"));
+      assertEquals(worker.getTaskQueue(), options.getTaskQueue());
+    }
+  }
+}

temporal-testing/src/test/java/io/temporal/testing/junit5/TestWorkflowExtensionTest.java

@@ -120,7 +120,8 @@ public void extensionShouldLaunchTestEnvironmentAndResolveParameters(
         () -> assertTrue(testEnv.isStarted()),
         () -> assertNotNull(workflowClient),
         () -> assertNotNull(activityClient),
-        () -> assertNotNull(workflowOptions.getTaskQueue()),
+        () -> assertTrue(workflowOptions.getTaskQueue().startsWith("WorkflowTest-")),
+        () -> assertEquals(worker.getTaskQueue(), workflowOptions.getTaskQueue()),
         () -> assertNotNull(worker),
         () ->
             assertEquals(