Step functions tasks do not correctly resolve imports/exports

[jogold]

• I'm submitting a ...

  • 🪲 bug report
  • 🚀 feature request
  • 📚 construct library gap
  • ☎️ security issue or vulnerability => Please see policy
  • ❓ support request => Please see note at the top of this template.

• What is the current behavior?
  The following code:

  const app = new App();

  // STACK1
  const stack1 = new Stack(app, 'stack1');
  const user = new iam.User(stack1, 'User');

  // STACK2
  const stack2 = new Stack(app, 'stack2');
  const taskFn = new lambda.Function(stack2, 'Function', {
    code: lambda.Code.inline('hello'),
    handler: 'index.handler',
    runtime: lambda.Runtime.NODEJS_8_10,
  });

  const task = new sfn.Task(stack2, 'Task', {
    task: new tasks.RunLambdaTask(taskFn, {
      payload: {
        userName: user.userName// import user from stack1
      },
    }),
  });

  new sfn.StateMachine(stack2, 'SM', {
    definition: task,
  });

results in the following DefinitionString in the AWS::StepFunctions::StateMachine resource (note the incorrect Ref on the user, User00B015A1 does not exist in this stack):

{
  "Fn::Join": [
    "",
    [
      "{\"StartAt\":\"Task\",\"States\":{\"Task\":{\"End\":true,\"Parameters\":{\"FunctionName\":\"",
      {
        "Ref": "Function76856677"
      },
      "\",\"Payload\":{\"userName\":\"",
      {
        "Ref": "User00B015A1"
      },
      "\"}},\"Type\":\"Task\",\"Resource\":\"arn:aws:states:::lambda:invoke\"}}}"
    ]
  ]
}

Now if we change the new sfn.StateMachine statement to add a name using the user name (to import it on a prop where it's correctly resolved):

new sfn.StateMachine(stack2, 'SM', {
  definition: task,
  stateMachineName: user.userName // use imported user name as machine name
});

Both DefinitionString and StateMachineName in the AWS::StepFunctions::StateMachine resource use a correct Fn::ImportValue:

{
  "DefinitionString": {
    "Fn::Join": [
      "",
      [
        "{\"StartAt\":\"Task\",\"States\":{\"Task\":{\"End\":true,\"Parameters\":{\"FunctionName\":\"",
        {
          "Ref": "Function76856677"
        },
        "\",\"Payload\":{\"userName\":\"",
        {
          "Fn::ImportValue": "stack1:ExportsOutputRefUser00B015A11BEAACCF"
        },
        "\"}},\"Type\":\"Task\",\"Resource\":\"arn:aws:states:::lambda:invoke\"}}}"
      ]
    ]
  },
  "RoleArn": {
    "Fn::GetAtt": [
      "SMRole49C19C48",
      "Arn"
    ]
  },
  "StateMachineName": {
    "Fn::ImportValue": "stack1:ExportsOutputRefUser00B015A11BEAACCF"
  }
}

• What is the expected behavior (or behavior of feature suggested)?
  Import/export should work in step functions tasks

• Please tell us about your environment:

  • CDK CLI Version: 1.0.0
  • Module Version: 1.0.0
  • OS: all
  • Language: all

[jogold]

Fixed by #3568