bug: Step Functions: State.EnteredTime format does not match AWS

[attila]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

I just noticed that the State.EnteredTime in the context object has a differently formatted timestamp compared to what's in the AWS service or in stepfunctions-local.

This mismatch of formats can also be observed between Execution.StartTime and State.EnteredTime, where the former is correct.

I only noticed this because we use State.EnteredTime as an "updated_at" attribute in our DynamoDB records.

Using the example below, the parsed output we receive is:

{
  "Result": {
    "Execution_StartTime": "2024-04-24T06:27:25.830Z",
    "State_EnteredTime": "2024-04-24T06:27:25.839938+00:00"
  }
}

Note the granularity of the sub-second element, and the timezone offset notation.

Expected Behavior

The date formats should match for both context attributes:

{
  "Result": {
    "Execution_StartTime": "2024-04-24T06:27:25.830Z",
    "State_EnteredTime": "2024-04-24T06:27:25.840Z"
  }
}

How are you starting LocalStack?

With a docker-compose file

Steps To Reproduce

How are you starting localstack (e.g., bin/localstack command, arguments, or docker-compose.yml)

docker compose up

Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

Create state machine

awslocal stepfunctions create-state-machine \
  --name 'example' \
  --role-arn "arn:aws:iam::000000000000:role/stepfunctions-role" \
  --definition '{"StartAt":"Debug","States":{"Debug":{"Type":"Pass","Parameters":{"Execution_StartTime.$":"$$.Execution.StartTime","State_EnteredTime.$":"$$.State.EnteredTime"},"ResultPath":"$.Result","End":true}}}'

Start an execution

awslocal stepfunctions start-execution \
  --state-machine-arn "arn:aws:states:eu-west-1:000000000000:stateMachine:example" \
  --name 'test1'

Describe execution

awslocal stepfunctions describe-execution \
  --execution-arn "arn:aws:states:eu-west-1:000000000000:execution:example:test1"

Environment

- OS: MacOS
- LocalStack: nightly (2024-04-23)

Anything else?

For readability, this is the state machine definition used in the above example:

{
  "StartAt": "Debug",
  "States": {
    "Debug": {
      "Type": "Pass",
      "Parameters": {
        "Execution_StartTime.$": "$$.Execution.StartTime",
        "State_EnteredTime.$": "$$.State.EnteredTime"
      },
      "ResultPath": "$.Result",
      "End": true
    }
  }
}