feat(aws-chatbot): allow adding a sns topic in existing SlackChannel (#…

…16643)

closes #15588

packages/@aws-cdk/aws-chatbot/README.md

@@ -17,6 +17,7 @@ This module is part of the [AWS Cloud Development Kit](https://github.com/aws/aw
 
 ```ts
 import * as chatbot from '@aws-cdk/aws-chatbot';
+import * as sns from '@aws-cdk/aws-sns';
 
 const slackChannel = new chatbot.SlackChannelConfiguration(this, 'MySlackChannel', {
   slackChannelConfigurationName: 'YOUR_CHANNEL_NAME',
@@ -31,6 +32,8 @@ slackChannel.addToRolePolicy(new iam.PolicyStatement({
   ],
   resources: ['arn:aws:s3:::abc/xyz/123.txt'],
 }));
+
+slackChannel.addNotificationTopic(new sns.Topic(this, 'MyTopic'))
 ```
 
 ## Log Group

packages/@aws-cdk/aws-chatbot/lib/slack-channel-configuration.ts

@@ -239,7 +239,6 @@ export class SlackChannelConfiguration extends SlackChannelConfigurationBase {
         } else {
           this.slackChannelConfigurationName = resourceName.substring('slack-channel/'.length);
         }
-
       }
     }
 
@@ -268,6 +267,12 @@ export class SlackChannelConfiguration extends SlackChannelConfigurationBase {
 
   readonly grantPrincipal: iam.IPrincipal;
 
+  /**
+   * The SNS topic that deliver notifications to AWS Chatbot.
+   * @attribute
+   */
+  private readonly notificationTopics: sns.ITopic[];
+
   constructor(scope: Construct, id: string, props: SlackChannelConfigurationProps) {
     super(scope, id, {
       physicalName: props.slackChannelConfigurationName,
@@ -279,12 +284,14 @@ export class SlackChannelConfiguration extends SlackChannelConfigurationBase {
 
     this.grantPrincipal = this.role;
 
+    this.notificationTopics = props.notificationTopics ?? [];
+
     const configuration = new CfnSlackChannelConfiguration(this, 'Resource', {
       configurationName: props.slackChannelConfigurationName,
       iamRoleArn: this.role.roleArn,
       slackWorkspaceId: props.slackWorkspaceId,
       slackChannelId: props.slackChannelId,
-      snsTopicArns: props.notificationTopics?.map(topic => topic.topicArn),
+      snsTopicArns: cdk.Lazy.list({ produce: () => this.notificationTopics.map(topic => topic.topicArn) }, { omitEmpty: true } ),
       loggingLevel: props.loggingLevel?.toString(),
     });
 
@@ -303,5 +310,13 @@ export class SlackChannelConfiguration extends SlackChannelConfigurationBase {
     this.slackChannelConfigurationArn = configuration.ref;
     this.slackChannelConfigurationName = props.slackChannelConfigurationName;
   }
+
+  /**
+   * Adds a SNS topic that deliver notifications to AWS Chatbot.
+   * @param notificationTopic
+   */
+  public addNotificationTopic(notificationTopic: sns.ITopic): void {
+    this.notificationTopics.push(notificationTopic);
+  }
 }
 

packages/@aws-cdk/aws-chatbot/test/slack-channel-configuration.test.ts

@@ -1,5 +1,5 @@
-import '@aws-cdk/assert-internal/jest';
 import { ABSENT } from '@aws-cdk/assert-internal';
+import '@aws-cdk/assert-internal/jest';
 import * as cloudwatch from '@aws-cdk/aws-cloudwatch';
 import * as iam from '@aws-cdk/aws-iam';
 import * as logs from '@aws-cdk/aws-logs';
@@ -99,6 +99,26 @@ describe('SlackChannelConfiguration', () => {
     });
   });
 
+  test('allows adding a Topic after creating the SlackChannel', () => {
+    const slackChannel = new chatbot.SlackChannelConfiguration(stack, 'MySlackChannel', {
+      slackWorkspaceId: 'ABC123',
+      slackChannelId: 'DEF456',
+      slackChannelConfigurationName: 'Test',
+    });
+
+    const topic = new sns.Topic(stack, 'MyTopic');
+    slackChannel.addNotificationTopic(topic);
+
+    expect(stack).toHaveResourceLike('AWS::Chatbot::SlackChannelConfiguration', {
+      ConfigurationName: 'Test',
+      SnsTopicArns: [
+        {
+          Ref: 'MyTopic86869434',
+        },
+      ],
+    });
+  });
+
   test('created with existing role', () => {
     const role = iam.Role.fromRoleArn(stack, 'Role', 'arn:aws:iam:::role/test-role');