fix(lambda): allow retryAttempts = -1 for infinite retries in EventSourceMapping (#34009)

### Issue # (if applicable)

Fixes #34007

This PR addresses an inconsistency in the validation logic for the `retryAttempts` property of Lambda `EventSourceMapping`.

Previously, although the documentation indicated that `-1` signifies infinite retries (and is the default), explicitly setting `retryAttempts: -1` would cause a `ValidationError` because the validation logic enforced a lower bound of 0.

This change updates the validation in `aws-cdk-lib/aws-lambda/lib/event-source-mapping.ts` to correctly allow `-1` as a valid value, aligning the implementation with the documented behavior.

Additionally, this PR includes:

*   Updates to the TSDoc for `retryAttempts` in `aws-cdk-lib/aws-lambda-event-sources/lib/stream.ts` to improve clarity regarding the valid range (`-1` or `0` to `10000`).
*   Updates to the unit tests in `aws-cdk-lib/aws-lambda/test/event-source-mapping.test.ts` to verify the corrected behavior.

Affected modules: `aws-lambda`, `aws-lambda-event-sources`

### Reason for this change



### Description of changes



### Describe any new or updated permissions being added




### Description of how you validated changes



### 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*

Author: pahud

packages/aws-cdk-lib/aws-lambda-event-sources/lib/stream.ts

@@ -99,16 +99,13 @@ export interface StreamEventSourceProps extends BaseStreamEventSourceProps {
   readonly maxRecordAge?: Duration;
 
   /**
-   * Maximum number of retry attempts
-   * Valid Range:
-   * * Minimum value of 0
-   * * Maximum value of 10000
+   * Maximum number of retry attempts.
    *
-   * The default value is -1, which sets the maximum number of retries to infinite.
-   * When MaximumRetryAttempts is infinite, Lambda retries failed records until
-   * the record expires in the event source.
+   * Set to -1 for infinite retries (until the record expires in the event source).
    *
-   * @default -1
+   * Valid Range: -1 (infinite) or 0 to 10000
+   *
+   * @default -1 (infinite retries)
    */
   readonly retryAttempts?: number;
 

packages/aws-cdk-lib/aws-lambda-event-sources/test/dynamo.test.ts

@@ -587,9 +587,9 @@ describe('DynamoEventSource', () => {
     // THEN
     expect(() =>
       fn.addEventSource(new sources.DynamoEventSource(table, {
-        retryAttempts: -1,
+        retryAttempts: -2, // Test an invalid negative value
         startingPosition: lambda.StartingPosition.LATEST,
-      }))).toThrow(/retryAttempts must be between 0 and 10000 inclusive, got -1/);
+      }))).toThrow(/retryAttempts must be -1 \(for infinite\) or between 0 and 10000 inclusive, got -2/);
   });
 
   test('fails if retryAttempts > 10000', () => {
@@ -609,7 +609,7 @@ describe('DynamoEventSource', () => {
       fn.addEventSource(new sources.DynamoEventSource(table, {
         retryAttempts: 10001,
         startingPosition: lambda.StartingPosition.LATEST,
-      }))).toThrow(/retryAttempts must be between 0 and 10000 inclusive, got 10001/);
+      }))).toThrow(/retryAttempts must be -1 \(for infinite\) or between 0 and 10000 inclusive, got 10001/);
   });
 
   test('specific bisectBatchOnFunctionError', () => {

packages/aws-cdk-lib/aws-lambda/lib/event-source-mapping.ts

@@ -451,8 +451,9 @@ export class EventSourceMapping extends cdk.Resource implements IEventSourceMapp
     }
 
     props.retryAttempts !== undefined && cdk.withResolved(props.retryAttempts, (attempts) => {
-      if (attempts < 0 || attempts > 10000) {
-        throw new ValidationError(`retryAttempts must be between 0 and 10000 inclusive, got ${attempts}`, this);
+      // Allow -1 for infinite retries, otherwise validate the 0-10000 range
+      if (!(attempts === -1 || (attempts >= 0 && attempts <= 10000))) {
+        throw new ValidationError(`retryAttempts must be -1 (for infinite) or between 0 and 10000 inclusive, got ${attempts}`, this);
       }
     });
 

packages/aws-cdk-lib/aws-lambda/test/event-source-mapping.test.ts

@@ -97,20 +97,20 @@ describe('event source mapping', () => {
     })).toThrow(/maxRecordAge must be between 60 seconds and 7 days inclusive/);
   });
 
-  test('throws if retryAttempts is negative', () => {
+  test('accepts retryAttempts = -1 for infinite retries', () => {
     expect(() => new EventSourceMapping(stack, 'test', {
       target: fn,
       eventSourceArn: '',
       retryAttempts: -1,
-    })).toThrow(/retryAttempts must be between 0 and 10000 inclusive, got -1/);
+    })).not.toThrow();
   });
 
   test('throws if retryAttempts is over 10000', () => {
     expect(() => new EventSourceMapping(stack, 'test', {
       target: fn,
       eventSourceArn: '',
       retryAttempts: 10001,
-    })).toThrow(/retryAttempts must be between 0 and 10000 inclusive, got 10001/);
+    })).toThrow(/retryAttempts must be -1 \(for infinite\) or between 0 and 10000 inclusive, got 10001/);
   });
 
   test('accepts if retryAttempts is a token', () => {