Fn::Split and Fn::Sub combination false positive

[romaninsh]

Resource: Resources > B3AdminIdentityPool > Properties > IdentityPoolName
Message: Fn::Split does not support function 'Fn::Sub' here
Documentation: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-split.html

code:

  B3AdminIdentityPool:
    Type: AWS::Cognito::IdentityPool
    Properties:
      IdentityPoolName: 
         Fn::Join: 
          - "_"
          - Fn::Split: 
            - "-"
            - !Sub ${Infra}-b3-admin

valid syntax replacing "-" with "_" in a string.

[martysweet]

Thanks for the issue, Fn::Sub needs to be added to the following list.

cfn-lint/data/aws_intrinsic_functions.json

Line 16 in c2690b1

"Fn::Split": {"supportedFunctions": ["Fn::Base64", "Fn::FindInMap", "Fn::GetAtt", "Fn::If", "Fn::Join", "Fn::Select", "Fn::ImportValue", "Ref"]},