Expose the ability to invoke grpc services from handler services, and viceversa. (#176)

Author: slinkydeveloper

src/restate_context.ts

@@ -180,18 +180,9 @@ export interface RestateBaseContext {
 // ----------------------------------------------------------------------------
 
 /**
- * The context that gives access to all Restate-backed operations, for example
- *   - sending reliable messages / rpc through Restate
- *   - access/update state (for keyed services)
- *   - side effects
- *   - sleeps and delayed calls
- *   - awakeables
- *   - ...
- *
- * This context is for use in **gRPC service** implementations.
- * For the rpc-handler API, use the {@link RpcContext} instead.
+ * Interface to interact with **gRPC** based services.
  */
-export interface RestateGrpcContext extends RestateBaseContext {
+export interface RestateGrpcChannel {
   /**
    * Unidirectional call to other Restate services ( = in background / async / not waiting on response).
    * To do this, wrap the call via the proto-ts client with oneWayCall, as shown in the example.
@@ -256,6 +247,27 @@ export interface RestateGrpcContext extends RestateBaseContext {
   ): Promise<Uint8Array>;
 }
 
+/**
+ * The context that gives access to all Restate-backed operations, for example
+ *   - sending reliable messages / rpc through Restate
+ *   - access/update state (for keyed services)
+ *   - side effects
+ *   - sleeps and delayed calls
+ *   - awakeables
+ *   - ...
+ *
+ * This context is for use in **gRPC service** implementations.
+ * For the rpc-handler API, use the {@link RpcContext} instead.
+ */
+export interface RestateGrpcContext
+  extends RestateBaseContext,
+    RestateGrpcChannel {
+  /**
+   * Get the {@link RpcGateway} to invoke Handler-API based services.
+   */
+  rpcGateway(): RpcGateway;
+}
+
 /**
  * For compatibility, we make the support 'RestateContext' as the type for the Grpc-based API context.
  */
@@ -323,18 +335,9 @@ export type ServiceApi<_M = unknown> = {
 };
 
 /**
- * The context that gives access to all Restate-backed operations, for example
- *   - sending reliable messages / RPC through Restate
- *   - access/update state (for keyed services)
- *   - side effects
- *   - sleeps and delayed calls
- *   - awakeables
- *   - ...
- *
- * This context is for use with the **rpc-handler API**.
- * For gRPC-based API, use the {@link RestateContext} instead.
+ * Interface to interact with **rpc-handler API** based services.
  */
-export interface RpcContext extends RestateBaseContext {
+export interface RpcGateway {
   /**
    * Makes a type-safe request/response RPC to the specified target service.
    *
@@ -463,3 +466,22 @@ export interface RpcContext extends RestateBaseContext {
    */
   sendDelayed<M>(opts: ServiceApi<M>, delay: number): SendClient<M>;
 }
+
+/**
+ * The context that gives access to all Restate-backed operations, for example
+ *   - sending reliable messages / RPC through Restate
+ *   - access/update state (for keyed services)
+ *   - side effects
+ *   - sleeps and delayed calls
+ *   - awakeables
+ *   - ...
+ *
+ * This context is for use with the **rpc-handler API**.
+ * For gRPC-based API, use the {@link RestateContext} instead.
+ */
+export interface RpcContext extends RestateBaseContext, RpcGateway {
+  /**
+   * Get the {@link RestateGrpcChannel} to invoke gRPC based services.
+   */
+  grpcChannel(): RestateGrpcChannel;
+}

src/restate_context_impl.ts

@@ -9,7 +9,13 @@
  * https://github.com/restatedev/sdk-typescript/blob/main/LICENSE
  */
 
-import { RestateGrpcContext, RpcContext, ServiceApi } from "./restate_context";
+import {
+  RestateGrpcChannel,
+  RestateGrpcContext,
+  RpcContext,
+  RpcGateway,
+  ServiceApi,
+} from "./restate_context";
 import { StateMachine } from "./state_machine";
 import {
   AwakeableEntryMessage,
@@ -397,6 +403,10 @@ export class RestateGrpcContextImpl implements RestateGrpcContext {
       );
     }
   }
+
+  rpcGateway(): RpcGateway {
+    return new RpcContextImpl(this);
+  }
 }
 
 async function executeWithRetries<T>(
@@ -555,4 +565,8 @@ export class RpcContextImpl implements RpcContext {
   public sleep(millis: number): Promise<void> {
     return this.ctx.sleep(millis);
   }
+
+  grpcChannel(): RestateGrpcChannel {
+    return this.ctx;
+  }
 }