Update event stream payload encoding function

lib/eventstream_rpc_utils.spec.ts

@@ -0,0 +1,37 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+import * as eventstream_rpc_utils from "./eventstream_rpc_utils";
+
+jest.setTimeout(5000);
+
+test('Encode string payload as base64', async () => {
+    let encodedPayload = eventstream_rpc_utils.encodePayloadAsString("HelloWorld");
+    expect(encodedPayload).toEqual("SGVsbG9Xb3JsZA==");
+});
+
+test('Encode ArrayBuffer payload as base64', async () => {
+    let buffer = new ArrayBuffer(10);
+    let writeView = new Uint8Array(buffer);
+    for (let i = 0; i < 10; i++) {
+        writeView[i] = 65;
+    }
+
+    let encodedPayload = eventstream_rpc_utils.encodePayloadAsString(buffer);
+    expect(encodedPayload).toEqual("QUFBQUFBQUFBQQ==");
+});
+
+test('Encode view payload as base64', async () => {
+    let buffer = new ArrayBuffer(10);
+    let writeView = new Uint8Array(buffer);
+    for (let i = 0; i < 10; i++) {
+        writeView[i] = 65;
+    }
+
+    let view = new DataView(buffer, 1, 8);
+
+    let encodedPayload = eventstream_rpc_utils.encodePayloadAsString(view);
+    expect(encodedPayload).toEqual("QUFBQUFBQUE=");
+});

lib/eventstream_rpc_utils.ts

@@ -20,7 +20,15 @@ import {CrtError, eventstream} from "aws-crt";
  * @return a base64-encoded string
  */
 export function encodePayloadAsString(payload : eventstream.Payload) : string {
-    return Buffer.from(payload).toString("base64");
+    if (ArrayBuffer.isView(payload)) {
+        return Buffer.from(payload.buffer, payload.byteOffset, payload.byteLength).toString("base64");
+    } else if (typeof payload === "string") {
+        let value = payload as string;
+        return Buffer.from(value).toString("base64");
+    } else {
+        let value = payload as ArrayBuffer;
+        return Buffer.from(value).toString("base64");
+    }
 }
 
 /**

package.json

@@ -28,7 +28,7 @@
   },
   "devDependencies": {
     "@types/jest": "^27.0.1",
-    "@types/node": "^10.17.54",
+    "@types/node": "^14.18.63",
     "@types/puppeteer": "^5.4.7",
     "@types/ws": "8.5.4",
     "cmake-js": "^7.3.0",