TypeError: data.join is not a function

[PatMyron]

cfn-dia html -t ~/Documents/GitHub/cfn-python-lint/test/fixtures/templates/bad/resources_circular_dependency_2.yaml

TypeError: data.join is not a function
    at Object.dump (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/yaml-cfn/index.js:39:24)
    at applyOverrides (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/yaml-cfn/index.js:44:49)
    at Type.represent (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/yaml-cfn/index.js:61:23)
    at detectType (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:695:26)
    at writeNode (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:720:5)
    at writeBlockMapping (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:657:10)
    at writeNode (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:750:9)
    at writeBlockMapping (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:657:10)
    at writeNode (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:750:9)
    at dump (/usr/local/lib/node_modules/@mhlabs/cfn-diagram/node_modules/js-yaml/lib/js-yaml/dumper.js:840:7)

Resources:
  Resource:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !Sub ${Resource2}
  Resource2:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !GetAtt Resource3.TopicName
  Resource3:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !Ref Resource4
  Resource4:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Fn::Sub: ${Resource5}
  Resource5:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Fn::GetAtt: Resource6.TopicName
  Resource6:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Ref: Resource7
  Resource7:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !Sub ${Resource8.TopicName}
  Resource8:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Fn::Sub: ${Resource9.TopicName}
  Resource9:
    DependsOn: Resource
    Type: AWS::SNS::Topic

(template from aws-cloudformation/cfn-lint#1391, aws-cloudformation/cfn-lint#1411)

[ljacobsson]

Thanks for reporting.

This error originates from the yaml-cfn parser.

You can only reference the atttribute using dot-notation when using the !GetAtt shorthand syntax. Changing this to Fn::GetAtt: [ Resource6, TopicName] or !GetAtt Resource6.TopicName will give you valid CloudFormation.

Please refer to the docs for Fn::GetAtt

I see you're using connections to visualise DependsOn-relationships. That's a good idea and I'll add an issue for that!

[ljacobsson]

I'll close this. Please reopen if you disagree :-)

[PatMyron]

will give you valid CloudFormation

This template successfully deploys, but maybe better filed downstream: https://github.com/gristlabs/yaml-cfn/issues

Resources:
  Resource:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !Sub ${Resource2}
  Resource2:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !GetAtt Resource3.TopicName
  Resource3:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !Ref Resource4
  Resource4:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Fn::Sub: ${Resource5}
  Resource5:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Fn::GetAtt: Resource6.TopicName
  Resource6:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Ref: Resource7
  Resource7:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        !Sub ${Resource8.TopicName}
  Resource8:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName:
        Fn::Sub: ${Resource9.TopicName}
  Resource9:
    # DependsOn: Resource
    Type: AWS::SNS::Topic

[chauncey-garrett]

@PatMyron I ran into a similar issue and ended up needing to convert from the shorthand notation !GetAtt Resource6.TopicName to the standard notation Fn::GetAtt: [ Resource6, TopicName].

Our template has also deployed successfully. I believe this issue is the result of a bug in the GetAtt override: https://github.com/gristlabs/yaml-cfn/blob/9a139dc48428f6bf01d7fb3334133cf56fe9e31c/index.js#L37-L40