Lambda Event Sources need to create a dependency to the OnFailure resource

Without the dependsOn being generated in the CFT the EventSource can be generated with an empty OnFailure destination.

Reproduction Steps

import cdk = require('@aws-cdk/core');
import dynamodb = require('@aws-cdk/aws-dynamodb');
import eventSource = require('@aws-cdk/aws-lambda-event-sources');
import lambda = require('@aws-cdk/aws-lambda');
import sqs = require('@aws-cdk/aws-sqs');
import {Construct} from "@aws-cdk/core";

export class CdkTestStack extends cdk.Stack {
  constructor(scope: cdk.App, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    const table = new dynamodb.Table(this, 'table', {
      partitionKey: {
        name: 'pk',
        type: dynamodb.AttributeType.STRING
      },
      stream: dynamodb.StreamViewType.NEW_IMAGE
    });

    const testlambda = new lambda.Function(this, 'TestFunction', {
      code: lambda.Code.fromInline('handler = () => console.log("handled");'),
      runtime: lambda.Runtime.NODEJS_12_X,
      handler: 'index.handler',
      description: 'Example function',
    });

    const sqsQueue = new sqs.Queue(this, 'sqsDLQ', {
    });

    testlambda.addEventSource(
        new eventSource.DynamoEventSource(table, {
          startingPosition: lambda.StartingPosition.TRIM_HORIZON,
          batchSize: 1,
          retryAttempts: 0,
          onFailure: new eventSource.SqsDlq(sqsQueue)
        })
    );
  }
}

Error Log

Environment

• **CLI Version : >1.29.0 **
• Framework Version:
• OS :
• Language :

Other

Register dependency on the DLQ with the EventSource when it is created.

Hack work around (added to stack):

    let dynamoDBEventSource = {} as Construct;

    for (let i = 0; i < testlambda.node.children.length; i++) {
        if (testlambda.node.children[i].node.uniqueId.includes('DynamoDBEventSource')) {
            dynamoDBEventSource = testlambda.node.children[i] as Construct;
        }
    }

    dynamoDBEventSource.node.addDependency(sqsQueue);

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This is 🐛 Bug Report

[nija-at]

I see. Yes, it’s semantically correct to have it defined, nevertheless.

[SomayaB]

Closing this issue for now since there hasn’t been a response in a while. Feel free to reopen.