cdk migrate: nested shortform functions fail to migrate

[Shwaring]

Describe the bug

Cloudformation intrinisc finctions have short froms and long forms. When functions using the short form you get the unhelpful error message migrate failed for : <stackname> could not be generated because <element>: untagged and internally tagged enums do not support enum input at line 141 column 25
I believe this error message is unrelated and is simply a fallback error for some reason.
The following snippet shows that converting to long form functions migrates correctly but the nested shortform functions fail.

Expected Behavior

Generate a valid CDK stack

Current Behavior

migrate fails with migrate failed for : <stackname> could not be generated because <element>: untagged and internally tagged enums do not support enum input at line <line> column <column> error

Reproduction Steps

run cdk migrate --stack-name my-stack --language typescript --from-path <template> --output-path <path for output> using

AWSTemplateFormatVersion: "2010-09-09"
Description: ABS Insights Aurora Postgres

Conditions:
  cUseDBSnapshot: 
    Fn::Not: 
      Fn::Equals: 
        - Ref: pDBSnapshotIdentifier
        - ""
  cAddCollectServicesIngress: 
    Fn::Not: 
      Fn::Equals: [Ref: pCollectServicesIP , ""]
  cAddCollectServices2Ingress: !Not [!Equals [!Ref pCollectServicesIP2 , ""]]
  cAddCollectServices3Ingress: !Not [!Equals [!Ref pCollectServicesIP3 , ""]]
  cAddCollectServices4Ingress: !Not [!Equals [!Ref pCollectServicesIP4 , ""]]
  cAddCollectServices5Ingress: !Not [!Equals [!Ref pCollectServicesIP5 , ""]]
  cArcGISFirstIPIngress: !Not [!Equals [!Ref pArcGISFirstIP , ""]]
  cArcGISSecondIPIngress: !Not [!Equals [!Ref pArcGISSecondIP , ""]]
  cCreateAdminSecret: !Not [!Condition cUseDBSnapshot]

Possible Solution

Current workaround is to expand these functions into the long forms

Additional Information/Context

No response

CDK CLI Version

2.145.0

Framework Version

No response

Node.js Version

v20.14.0

OS

linux

Language

TypeScript

Language Version

No response

Other information

No response

[ashishdhingra]

Reproducible. Looking at the code for cdk migrate:

• It invokes migrate() which does the heavy lifting for the command.
• For CFN template passed as a path, it deserialized the template string body by invoking deserializeStructure() here.
• deserializeStructure() executes yaml_cfn.deserialize(), which uses yaml.parse() from yaml package.
  • It leverages shortForms, makeTagForCfnIntrinsic() and parseYamlStrWithCfnTags() during this process.
  • For tags Base64, Cidr, FindInMap, GetAZs, ImportValue, Join, Sub, Select, Split, Transform, And, Equals, If, Not, Or and GetAtt, it expands these to contain prefix Fn:: here. (For tags Ref and Condition, it doesn't add Fn:: prefix)

Unsure if this is root cause. Needs more investigation.

[Shwaring]

Hey, not sure if this is what you are implying, but the ref function long form is not supposed to have the 'Fn::' prefix see docs
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-ref.html

[ashishdhingra]

Hey, not sure if this is what you are implying, but the ref function long form is not supposed to have the 'Fn::' prefix see docs https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-ref.html

@Shwaring Thanks for sharing the link. I just added my findings in #30810 (comment). Is it possible to share minimal almost complete template? The error might be thrown my yaml package (not entirely sure though). I also mentioned in my previous comment that For tags Ref and Condition, it doesn't add Fn:: prefix.

[Shwaring]

AWSTemplateFormatVersion: 2010-09-09
Description: example

Parameters:

  pExample:
    Type: String
    Description: example paramater
    Default: param
Conditions:
  cNotBrokenCondition: 
    Fn::Not: 
      Fn::Equals: 
        - Ref: pExample
        - ""
  cAlsoNotBrokenCondition: 
    Fn::Not: 
      Fn::Equals: [Ref: pExample , ""]
  cBrokenCondition: !Not [!Equals [!Ref pExample , ""]]
Resources:

[ashishdhingra]

@Shwaring Thanks for providing the sample template. Running cdk migrate on this template gives below error:

This command is an experimental feature.
 ❌  Migrate failed for `my-stack`: MyStackStack could not be generated because Conditions.cBrokenCondition[0]: untagged and internally tagged enums do not support enum input at line 19 column 27

MyStackStack could not be generated because Conditions.cBrokenCondition[0]: untagged and internally tagged enums do not support enum input at line 19 column 27

Upon searching through existing issues, it appears that this is similar to #29181. Please review.

Thanks,
Ashish

[Shwaring]

Yep I believe that is the same issue

[ashishdhingra]

Yep I believe that is the same issue

@Shwaring Thanks for the confirmation. I will bring this and other issue to team's attention. Most likely would close this one since team might be tracking other issue internally.

[Shwaring]

Has any progress been made on this issue? I am planning on migrate another set of CFN templates soon.