bug: 'unknown tag !<!ToJsonString>'

[sliedig]

Running iam-pol against template with new CloudFormation Language extensions

AWSTemplateFormatVersion: 2010-09-09
Transform:
  - AWS::LanguageExtensions
  - AWS::Serverless-2016-10-31

example of usagae

  DdbStreamToEventPipe:
    Type: AWS::Pipes::Pipe
    Properties:
      RoleArn: !GetAtt DdbStreamToEventPipeRole.Arn
      Source: !GetAtt ContractsTable.StreamArn
      SourceParameters:
        DynamoDBStreamParameters:
          StartingPosition: LATEST
          OnPartialBatchItemFailure: AUTOMATIC_BISECT
          BatchSize: 1
        FilterCriteria:
          Filters:
            - Pattern: !ToJsonString
                eventName: [INSERT, MODIFY]
                dynamodb:
                  NewImage:
                    ContractStatus:
                      S: [DRAFT, APPROVED]
      Target: !GetAtt UnicornContractsEventBus.Arn
      TargetParameters:
        EventBridgeEventBusParameters:
          Source: !Sub "{{resolve:ssm:/uni-prop/${Stage}/UnicornContractsNamespace}}"
          DetailType: ContractStatusChanged
        InputTemplate: !ToJsonString
          PropertyId: "<$.dynamodb.NewImage.PropertyId.S>"
          ContractId: "<$.dynamodb.NewImage.ContractId.S>"
          ContractStatus: "<$.dynamodb.NewImage.ContractStatus.S>"
          ContractLastModifiedOn: "<$.dynamodb.NewImage.ContractLastModifiedOn.S>"