fix(lambda-event-sources): dynamo batch size cannot be a CfnParameter (…

…#16540) fixes #16221 ---- *By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*
aws · Oct 29, 2021 · 56974ac · 56974ac
1 parent 7a333b0
commit 56974ac
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Showing 2 changed files with 47 additions and 2 deletions.
diff --git a/packages/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.ts b/packages/@aws-cdk/aws-lambda-event-sources/lib/dynamodb.ts
@@ -1,6 +1,6 @@
 import * as dynamodb from '@aws-cdk/aws-dynamodb';
 import * as lambda from '@aws-cdk/aws-lambda';
-import { Names } from '@aws-cdk/core';
+import { Names, Token } from '@aws-cdk/core';
 import { StreamEventSource, StreamEventSourceProps } from './stream';
 
 export interface DynamoEventSourceProps extends StreamEventSourceProps {
@@ -15,7 +15,9 @@ export class DynamoEventSource extends StreamEventSource {
   constructor(private readonly table: dynamodb.ITable, props: DynamoEventSourceProps) {
     super(props);
 
-    if (this.props.batchSize !== undefined && (this.props.batchSize < 1 || this.props.batchSize > 1000)) {
+    if (this.props.batchSize !== undefined
+      && !Token.isUnresolved(this.props.batchSize)
+      && (this.props.batchSize < 1 || this.props.batchSize > 1000)) {
       throw new Error(`Maximum batch size must be between 1 and 1000 inclusive (given ${this.props.batchSize})`);
     }
   }

diff --git a/packages/@aws-cdk/aws-lambda-event-sources/test/dynamo.test.ts b/packages/@aws-cdk/aws-lambda-event-sources/test/dynamo.test.ts
@@ -136,6 +136,49 @@ describe('DynamoEventSource', () => {
     });
 
 
+  });
+
+  test('pass validation if batchsize is token', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const table = new dynamodb.Table(stack, 'T', {
+      partitionKey: {
+        name: 'id',
+        type: dynamodb.AttributeType.STRING,
+      },
+      stream: dynamodb.StreamViewType.NEW_IMAGE,
+    });
+    const batchSize = new cdk.CfnParameter(stack, 'BatchSize', {
+      type: 'Number',
+      default: 100,
+      minValue: 1,
+      maxValue: 1000,
+    });
+    // WHEN
+    fn.addEventSource(new sources.DynamoEventSource(table, {
+      batchSize: batchSize.valueAsNumber,
+      startingPosition: lambda.StartingPosition.LATEST,
+    }));
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties('AWS::Lambda::EventSourceMapping', {
+      'EventSourceArn': {
+        'Fn::GetAtt': [
+          'TD925BC7E',
+          'StreamArn',
+        ],
+      },
+      'FunctionName': {
+        'Ref': 'Fn9270CBC0',
+      },
+      'BatchSize': {
+        'Ref': 'BatchSize',
+      },
+      'StartingPosition': 'LATEST',
+    });
+
+
   });
 
   test('fails if streaming not enabled on table', () => {