(aws-stepfunctions): Can't add Jsonata strings to toleratedFailurePercentage

[NikHammon]

Describe the bug

When trying to create a DistributedMap with a jsonata string passed in for the toleratedFailurePercentage it is not typesafe and I get a validation error saying that it must be a number that prevents me from generating the definition that I want.

I have tried uploading a jsonata string to the definition body in the aws console so I know its allowed and the doc agree.

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Version

No response

Expected Behavior

I would expect that I am allowed to use a jsonata variable string for the distributed map failure threshold as specified in the doc.

Current Behavior

Error: Validation failed with the following errors:
  [.../Map] toleratedFailurePercentage must be between 0 and 100

Reproduction Steps

const map = DistributedMap.jsonata(this, 'Map', {
      stateName: 'My map',
      items: ProvideItems.jsonata(...),

      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
      // @ts-ignore
      toleratedFailurePercentage: '{% $myThreshold %}', <<-- This causes a validation error
    })

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

^2.178.1

Framework Version

No response

Node.js Version

v20.18.2

OS

OSX

Language

TypeScript

Language Version

No response

Other information

No response

[pahud]

Thanks for raising this issue.

After investigation, the root cause is that the DistributedMap construct in AWS CDK does not currently support passing a Jsonata expression to dynamically set the tolerated failure percentage.

Details:

• The DistributedMap API only accepts a static number for toleratedFailurePercentage.
• The toleratedFailurePercentagePath property, which allows dynamic values, is only supported in JSONPath mode, not in Jsonata mode.
• Attempting to pass a Jsonata string like '{% $myThreshold %}' results in a validation error or is ignored.

Expected Behavior:

Since AWS Step Functions supports Jsonata expressions for this field in the ASL definition, the CDK should ideally allow users to specify a Jsonata expression dynamically.

Recommendation:

Enhance the CDK DistributedMap construct to support:

• Passing a Jsonata expression for tolerated failure percentage, either by:
  • Extending toleratedFailurePercentagePath to accept Jsonata strings in Jsonata mode, or
  • Introducing a new property such as toleratedFailurePercentageExpression.

This would align the CDK API with Step Functions capabilities and enable dynamic, data-driven workflows.

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Making this a p2 feature request. Please add 👍 to help us prioritize and we welcome PRs as well.

Thanks!