Return a specific typed Promise<InvokeBindingResponseType> instead of Promise<object>

src/implementation/Client/GRPCClient/binding.ts

@@ -12,8 +12,47 @@ limitations under the License.
 */
 
 import GRPCClient from './GRPCClient';
-import { InvokeBindingRequest, InvokeBindingResponse } from '../../../proto/dapr/proto/runtime/v1/dapr_pb';
+import {
+  InvokeBindingRequest as AutogeneratedInvokeBindingRequest,
+  InvokeBindingResponse as AutogeneratedInvokeBindingResponse,
+} from '../../../proto/dapr/proto/runtime/v1/dapr_pb';
 import IClientBinding from '../../../interfaces/Client/IClientBinding';
+import { types } from 'util';
+import { InvokeBindingResponse } from '../../../types/binding/InvokeBindingResponse.type';
+
+export class BindingRequest {
+  public readonly bindingName: string;
+  public readonly operation: string;
+  public data?: any;
+  public metadata: Record<string, string>;
+
+  constructor(bindingName: string, operation: string) {
+    this.bindingName = bindingName;
+    this.operation = operation;
+
+    this.metadata = {};
+  }
+
+  public setData(data: any) {
+    this.data = data;
+  }
+
+  public setMetadata(metadata: Record<string, string>) {
+    this.metadata = metadata;
+  }
+}
+
+export class BindingResponse implements InvokeBindingResponse {
+  public readonly operation: string;
+  public readonly data: Uint8Array | string;
+  public readonly metadata: Record<string, string>;
+
+  constructor(operation: string, data: Uint8Array | string, metadata: Record<string, string>) {
+    this.operation = operation;
+    this.data = data;
+    this.metadata = metadata;
+  }
+}
 
 // https://docs.dapr.io/reference/api/bindings_api/
 export default class GRPCClientBinding implements IClientBinding {
@@ -23,29 +62,65 @@ export default class GRPCClientBinding implements IClientBinding {
     this.client = client;
   }
 
-  // Send an event to an external system
-  // @todo: should pass the metadata object
-  // @todo: should return a specific typed Promise<TypeBindingResponse> instead of Promise<object>
-  async send(bindingName: string, operation: string, data: any, _metadata: object = {}): Promise<object> {
-    const msgService = new InvokeBindingRequest();
-    msgService.setName(bindingName);
-    msgService.setOperation(operation);
-    msgService.setData(Buffer.from(JSON.stringify(data), "utf-8"));
+  private makeRequest(
+    name: string,
+    operation: string,
+    data: any,
+    metadata: Record<string, string>,
+  ): Promise<AutogeneratedInvokeBindingResponse> {
+    const envelope = new AutogeneratedInvokeBindingRequest();
+    envelope.setName(name);
+    envelope.setOperation(operation);
+    envelope.setData(data);
+    Object.keys(metadata).forEach((key) => {
+      envelope.getMetadataMap().set(key, metadata[key]);
+    });
 
     return new Promise((resolve, reject) => {
       const client = this.client.getClient();
-      client.invokeBinding(msgService, (err, res: InvokeBindingResponse) => {
-        if (err) {
-          return reject(err);
-        }
-
-        // https://docs.dapr.io/reference/api/bindings_api/#payload
-        return resolve({
-          data: res.getData(),
-          metadata: res.getMetadataMap(),
-          operation
-        });
+      client.invokeBinding(envelope, (err, res) => {
+        if (err) return reject(err);
+        return resolve(res);
       });
     });
   }
+
+  private keyValuePairList2Record(kvpArray: Array<[string, string]>): Record<string, string> {
+    const record: Record<string, string> = {};
+    for (const kvp of kvpArray) {
+      if (kvp.length !== 2) {
+        throw new Error('Invalid key-value pair');
+      }
+      record[kvp[0]] = kvp[1];
+    }
+    return record;
+  }
+
+  async invoke(request: BindingRequest): Promise<BindingResponse> {
+    // Sometimes we need to upload files to the object storage through binding, do not serialize binary data.
+    let payload = request.data;
+    if (!types.isTypedArray(request.data)) {
+      payload = Buffer.from(JSON.stringify(request.data), 'utf-8');
+    }
+
+    const response = await this.makeRequest(request.bindingName, request.operation, payload, request.metadata);
+    return new BindingResponse(
+      request.operation,
+      response.getData(),
+      this.keyValuePairList2Record(response.getMetadataMap().getEntryList()),
+    );
+  }
+
+  // Send an event to an external system
+  async send(
+    bindingName: string,
+    operation: string,
+    data: any,
+    metadata: Record<string, string>,
+  ): Promise<BindingResponse> {
+    const request = new BindingRequest(bindingName, operation);
+    request.setData(data);
+    request.setMetadata(metadata);
+    return await this.invoke(request);
+  }
 }

src/implementation/Client/HTTPClient/binding.ts

@@ -13,6 +13,7 @@ limitations under the License.
 
 import HTTPClient from './HTTPClient';
 import IClientBinding from '../../../interfaces/Client/IClientBinding';
+import { InvokeBindingResponse } from '../../../types/binding/InvokeBindingResponse.type';
 
 // https://docs.dapr.io/reference/api/bindings_api/
 export default class HTTPClientBinding implements IClientBinding {
@@ -23,7 +24,7 @@ export default class HTTPClientBinding implements IClientBinding {
   }
 
   // Send an event to an external system
-  async send(bindingName: string, operation: string, data: any, metadata: object = {}): Promise<object> {
+  async send(bindingName: string, operation: string, data: any, metadata: object = {}): Promise<InvokeBindingResponse> {
     const result = await this.client.execute(`/bindings/${bindingName}`, {
       method: 'POST',
       headers: {
@@ -32,10 +33,14 @@ export default class HTTPClientBinding implements IClientBinding {
       body: JSON.stringify({
         operation,
         data,
-        metadata
+        metadata,
       }),
     });
 
-    return result as object;
+    return {
+      data: result,
+      operation,
+      metadata: {},
+    };
   }
 }

src/interfaces/Client/IClientBinding.ts

@@ -11,6 +11,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { InvokeBindingResponse } from "../../types/binding/InvokeBindingResponse.type";
+
 export default interface IClientBinding {
-    send(bindingName: string, operation: string, data: any, metadata?: object): Promise<object>;
+    send(bindingName: string, operation: string, data: any, metadata?: object): Promise<InvokeBindingResponse>;
 }

src/types/binding/InvokeBindingResponse.type.ts

@@ -0,0 +1,18 @@
+/*
+Copyright 2022 The Dapr Authors
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file 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.
+*/
+
+export type InvokeBindingResponse = {
+    data: any;
+    operation: string;
+    metadata: Record<string, string>;
+}