Expose Temporal Nexus operation info to Temporal Nexus operation (#1896)

Author: Quinn-With-Two-Ns

packages/nexus/src/context.ts

@@ -33,6 +33,23 @@ export interface HandlerContext {
   taskQueue: string;
 }
 
+/**
+ * Holds information about the current Nexus Operation Execution.
+ *
+ * @experimental Nexus support in Temporal SDK is experimental.
+ */
+export interface OperationInfo {
+  /**
+   * Namespace this Nexus Operation is executing in
+   */
+  readonly namespace: string;
+
+  /**
+   * Task Queue this Nexus Operation is executing on
+   */
+  readonly taskQueue: string;
+}
+
 // Basic APIs //////////////////////////////////////////////////////////////////////////////////////
 
 /**
@@ -101,3 +118,18 @@ export const metricMeter: MetricMeter = {
 export function getClient(): Client {
   return getHandlerContext().client;
 }
+
+/**
+ * Get information about the current Nexus Operation.
+ *
+ * @return OperationInfo for the current Nexus Operation being executed
+ *
+ * @experimental Nexus support in Temporal SDK is experimental.
+ */
+export function operationInfo(): OperationInfo {
+  const ctx = getHandlerContext();
+  return {
+    namespace: ctx.namespace,
+    taskQueue: ctx.taskQueue,
+  };
+}

packages/nexus/src/index.ts

@@ -9,6 +9,8 @@ export {
   log,
   getClient,
   metricMeter,
+  operationInfo,
+  type OperationInfo,
 } from './context';
 
 export {

packages/test/src/test-nexus-handler.ts

@@ -588,6 +588,45 @@ test('getClient is available in handler context', async (t) => {
   });
 });
 
+test('operationInfo is available in handler context', async (t) => {
+  const { env, taskQueue, httpPort, endpointId } = t.context;
+
+  const w = await Worker.create({
+    connection: env.nativeConnection,
+    namespace: env.namespace,
+    taskQueue,
+    nexusServices: [
+      nexus.serviceHandler(
+        nexus.service('testService', {
+          testSyncOp: nexus.operation<void, { namespace: string; taskQueue: string }>(),
+        }),
+        {
+          async testSyncOp() {
+            const info = temporalnexus.operationInfo();
+            return {
+              namespace: info.namespace,
+              taskQueue: info.taskQueue,
+            };
+          },
+        }
+      ),
+    ],
+  });
+
+  await w.runUntil(async () => {
+    const res = await fetch(
+      `http://127.0.0.1:${httpPort}/nexus/endpoints/${endpointId}/services/testService/testSyncOp`,
+      {
+        method: 'POST',
+      }
+    );
+    t.true(res.ok);
+    const output = (await res.json()) as { namespace: string; taskQueue: string };
+    t.is(output.namespace, 'default');
+    t.is(output.taskQueue, taskQueue);
+  });
+});
+
 test('WorkflowRunOperationHandler attaches callback, link, and request ID', async (t) => {
   const { env, taskQueue, httpPort, endpointId } = t.context;
   const requestId1 = randomUUID();