better type guarding

packages/chat-core-aws-connect/src/infra/ChatCoreAwsConnectImpl.ts

@@ -4,6 +4,7 @@ import { AwsConnectEvent } from "../models/AwsConnectEvent";
 import { EventMap, EventCallback } from "../models/EventCallback";
 import { LoggerConfig } from "../models/LoggerConfig";
 import { ChatCoreAwsConnectConfig } from "../models/ChatCoreAwsConnectConfig";
+import { isCustomerChatSession } from "../models/ChatSession";
 import "amazon-connect-chatjs";
 
 /**
@@ -12,7 +13,7 @@ import "amazon-connect-chatjs";
  * @internal
  */
 export class ChatCoreAwsConnectImpl implements ChatCoreAwsConnect {
-  private session?: connect.ActiveChatSession;
+  private session?: connect.ActiveCustomerChatSession;
   private eventListeners: { [T in keyof EventMap]?: EventCallback<T>[] } = {};
   private loggerConfig: LoggerConfig = {
     level: "ERROR",
@@ -51,11 +52,16 @@ export class ChatCoreAwsConnectImpl implements ChatCoreAwsConnect {
       region: messageRsp.integrationDetails?.awsConnectHandoff?.region,
     });
 
-    this.session = connect.ChatSession.create({
+    const sess = connect.ChatSession.create({
       chatDetails: connectionCreds,
       type: "CUSTOMER",
     });
 
+    if (!isCustomerChatSession(sess)) {
+      throw new Error("Unexpected non-customer chat session type");
+    }
+    this.session = sess;
+
     const { connectCalled, connectSuccess } = await this.session.connect({});
     if (!connectCalled || !connectSuccess) {
       throw new Error("Failed to connect to chat session");
@@ -136,8 +142,7 @@ export class ChatCoreAwsConnectImpl implements ChatCoreAwsConnect {
       return;
     }
 
-    const customerSession = this.session as connect.ActiveCustomerChatSession;
-    customerSession.disconnectParticipant();
+    this.session.disconnectParticipant();
     this.session = undefined;
   }
 }

packages/chat-core-aws-connect/src/models/ChatSession.ts

@@ -0,0 +1,14 @@
+/**
+ * Returns true if the Amazon connect chat session is a customer chat session.
+ * @param session - The Amazon connect chat session.
+ *
+ * @internal
+ */
+export function isCustomerChatSession(
+  session: connect.ActiveChatSession
+): session is connect.ActiveCustomerChatSession {
+  return (
+    (session as connect.ActiveCustomerChatSession).disconnectParticipant !==
+    undefined
+  );
+}

packages/chat-core-aws-connect/tests/ChatCoreAwsConnect.test.ts

@@ -6,7 +6,6 @@ import {
   AwsConnectEventData,
 } from "../src/models/AwsConnectEvent";
 import "amazon-connect-chatjs";
-import "../src/models/connect";
 
 const createSpy = jest.fn().mockReturnValue(mockChatSession());
 const globalConfigSpy = jest.fn();
@@ -389,3 +388,13 @@ it("noops when clearing undefined session", async () => {
   chatCoreAwsConnect.resetSession();
   expect(chatCoreAwsConnect.getSession()).toBeUndefined();
 });
+
+it("throws error when session is not a customer session", async () => {
+  const sess = {} as unknown as connect.ActiveChatSession;
+  createSpy.mockReturnValue(sess);
+
+  const chatCoreAwsConnect = provideChatCoreAwsConnect();
+  expect(() => chatCoreAwsConnect.init(mockMessageResponse())).rejects.toThrow(
+    "Unexpected non-customer chat session type"
+  );
+});