feat(events): add description property for eventBus (#30935)

### Issue # (if applicable)

N/A

### Reason for this change
The change introduces the `description` property to the `EventBus`

### Description of changes
- Add the `description` property for `EventBusProps`, which was missing in the L2 construct.
- Add validation for character limit 

### Description of how you validated changes
I Added a unit test for eventBus and added the `description` property in the integration tests.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk-testing/framework-integ/test/aws-events/test/integ.eventbus.js.snapshot/Stack.template.json

@@ -3,6 +3,7 @@
   "BusEA82B648": {
    "Type": "AWS::Events::EventBus",
    "Properties": {
+    "Description": "myEventBus",
     "Name": "StackBusAA0A1E4B"
    }
   },

packages/@aws-cdk-testing/framework-integ/test/aws-events/test/integ.eventbus.ts

@@ -5,7 +5,9 @@ import { EventBus } from 'aws-cdk-lib/aws-events';
 
 const app = new App();
 const stack = new Stack(app, 'Stack');
-const bus = new EventBus(stack, 'Bus');
+const bus = new EventBus(stack, 'Bus', {
+  description: 'myEventBus',
+});
 
 bus.addToResourcePolicy(new iam.PolicyStatement({
   effect: iam.Effect.ALLOW,

packages/aws-cdk-lib/aws-events/README.md

@@ -208,7 +208,8 @@ It is possible to archive all or some events sent to an event bus. It is then po
 
 ```ts
 const bus = new events.EventBus(this, 'bus', {
-  eventBusName: 'MyCustomEventBus'
+  eventBusName: 'MyCustomEventBus',
+  description: 'MyCustomEventBus',
 });
 
 bus.archive('MyArchive', {

packages/aws-cdk-lib/aws-events/lib/event-bus.ts

@@ -80,6 +80,17 @@ export interface EventBusProps {
    */
   readonly eventSourceName?: string;
 
+  /**
+   * The event bus description.
+   *
+   * The description can be up to 512 characters long.
+   *
+   * @see http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-events-eventbus.html#cfn-events-eventbus-description
+   *
+   * @default - no description
+   */
+  readonly description?: string;
+
   /**
   * The customer managed key that encrypt events on this event bus.
   *
@@ -325,9 +336,14 @@ export class EventBus extends EventBusBase {
 
     super(scope, id, { physicalName: eventBusName });
 
+    if (props?.description && !Token.isUnresolved(props.description) && props.description.length > 512) {
+      throw new Error(`description must be less than or equal to 512 characters, got ${props.description.length}`);
+    }
+
     const eventBus = new CfnEventBus(this, 'Resource', {
       name: this.physicalName,
       eventSourceName,
+      description: props?.description,
       kmsKeyIdentifier: props?.kmsKey?.keyArn,
     });
 

packages/aws-cdk-lib/aws-events/test/event-bus.test.ts

@@ -48,6 +48,21 @@ describe('event bus', () => {
     });
   });
 
+  test('event bus with description', () => {
+    // GIVEN
+    const stack = new Stack();
+
+    // WHEN
+    new EventBus(stack, 'myEventBus', {
+      description: 'myEventBusDescription',
+    });
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties('AWS::Events::EventBus', {
+      Description: 'myEventBusDescription',
+    });
+  });
+
   test('partner event bus', () => {
     // GIVEN
     const stack = new Stack();
@@ -281,6 +296,19 @@ describe('event bus', () => {
     }).toThrow(/'eventSourceName' must satisfy: /);
   });
 
+  test('event bus description cannot be too long', () => {
+    // GIVEN
+    const stack = new Stack();
+    const tooLongDescription = 'a'.repeat(513);
+
+    // WHEN / THEN
+    expect(() => {
+      new EventBus(stack, 'EventBusWithTooLongDescription', {
+        description: tooLongDescription,
+      });
+    }).toThrow('description must be less than or equal to 512 characters, got 513');
+  });
+
   testDeprecated('can grant PutEvents', () => {
     // GIVEN
     const stack = new Stack();