feat(nexus): Early Nexus handler support

package.json

@@ -43,12 +43,14 @@
     "@temporalio/common": "file:packages/common",
     "@temporalio/create": "file:packages/create-project",
     "@temporalio/interceptors-opentelemetry": "file:packages/interceptors-opentelemetry",
+    "@temporalio/nexus": "file:packages/nexus",
     "@temporalio/nyc-test-coverage": "file:packages/nyc-test-coverage",
     "@temporalio/proto": "file:packages/proto",
     "@temporalio/test": "file:packages/test",
     "@temporalio/testing": "file:packages/testing",
     "@temporalio/worker": "file:packages/worker",
     "@temporalio/workflow": "file:packages/workflow",
+    "nexus-rpc": "github:nexus-rpc/sdk-typescript#pull/6/head",
     "temporalio": "file:packages/meta"
   },
   "devDependencies": {
@@ -86,6 +88,7 @@
     "packages/core-bridge",
     "packages/create-project",
     "packages/interceptors-opentelemetry",
+    "packages/nexus",
     "packages/nyc-test-coverage",
     "packages/proto",
     "packages/test",

packages/client/src/internal.ts

@@ -0,0 +1,28 @@
+import { temporal } from '@temporalio/proto';
+
+// A key used internally to pass "hidden options to the WorkflowClient.start() call.
+export const InternalWorkflowStartOptionsKey = Symbol.for('__temporal_client_internal_workflow_start_options');
+
+// Hidden internal workflow start options, used by the temporal nexus helpers.
+export interface InternalWorkflowStartOptions {
+  requestId?: string;
+  /**
+   * Callbacks to be called by the server when this workflow reaches a terminal state.
+   * If the workflow continues-as-new, these callbacks will be carried over to the new execution.
+   * Callback addresses must be whitelisted in the server's dynamic configuration.
+   */
+  completionCallbacks?: temporal.api.common.v1.ICallback[];
+  /** Links to be associated with the workflow. */
+  links?: temporal.api.common.v1.ILink[];
+  /**
+   * Backlink copied by the client from the StartWorkflowExecutionResponse. Only populated in servers newer than 1.27.
+   */
+  backLink?: temporal.api.common.v1.ILink;
+
+  /**
+   * Conflict options for when USE_EXISTING is specified.
+   *
+   * Used by the nexus WorkflowRunOperations to attach to a callback to a running workflow.
+   */
+  onConflictOptions?: temporal.api.workflow.v1.IOnConflictOptions;
+}

packages/client/src/workflow-client.ts

@@ -91,6 +91,7 @@ import {
 } from './base-client';
 import { mapAsyncIterable } from './iterators-utils';
 import { WorkflowUpdateStage, encodeWorkflowUpdateStage } from './workflow-update-stage';
+import { InternalWorkflowStartOptions, InternalWorkflowStartOptionsKey } from './internal';
 
 const UpdateWorkflowExecutionLifecycleStage = temporal.api.enums.v1.UpdateWorkflowExecutionLifecycleStage;
 
@@ -1252,7 +1253,14 @@ export class WorkflowClient extends BaseClient {
     const req = await this.createStartWorkflowRequest(input);
     const { options: opts, workflowType } = input;
     try {
-      return (await this.workflowService.startWorkflowExecution(req)).runId;
+      const response = await this.workflowService.startWorkflowExecution(req);
+      const internalOptions = (opts as any)[InternalWorkflowStartOptionsKey] as
+        | InternalWorkflowStartOptions
+        | undefined;
+      if (internalOptions != null) {
+        internalOptions.backLink = response.link ?? undefined;
+      }
+      return response.runId;
     } catch (err: any) {
       if (err.code === grpcStatus.ALREADY_EXISTS) {
         throw new WorkflowExecutionAlreadyStartedError(
@@ -1268,11 +1276,12 @@ export class WorkflowClient extends BaseClient {
   protected async createStartWorkflowRequest(input: WorkflowStartInput): Promise<StartWorkflowExecutionRequest> {
     const { options: opts, workflowType, headers } = input;
     const { identity, namespace } = this.options;
+    const internalOptions = (opts as any)[InternalWorkflowStartOptionsKey] as InternalWorkflowStartOptions | undefined;
 
     return {
       namespace,
       identity,
-      requestId: uuid4(),
+      requestId: internalOptions?.requestId ?? uuid4(),
       workflowId: opts.workflowId,
       workflowIdReusePolicy: encodeWorkflowIdReusePolicy(opts.workflowIdReusePolicy),
       workflowIdConflictPolicy: encodeWorkflowIdConflictPolicy(opts.workflowIdConflictPolicy),
@@ -1298,6 +1307,7 @@ export class WorkflowClient extends BaseClient {
       header: { fields: headers },
       priority: opts.priority ? compilePriority(opts.priority) : undefined,
       versioningOverride: opts.versioningOverride ?? undefined,
+      ...internalOptions,
     };
   }
 

packages/common/package.json

@@ -15,6 +15,7 @@
     "@temporalio/proto": "file:../proto",
     "long": "^5.2.3",
     "ms": "^3.0.0-canary.1",
+    "nexus-rpc": "github:nexus-rpc/sdk-typescript#pull/6/head",
     "proto3-json-serializer": "^2.0.0"
   },
   "devDependencies": {