State 'XYZ' already has a next state AWS CDK

[noddyStark]

I'm pretty new to AWS CDK and trying to trigger different steps in step function depending upon when a certain condition is met multiple times.

But when I try to implement the code I get the error
State 'step_3' already has a next state.

I'm basically trying to trigger different lambdas depending upon the condition of 'requestType', if after step_1, the condition requestType is equal to OD3, step_2 will be triggered which will end up invoking the lambda, so steps should be triggered in the following manner step_2 -> step_3 -> step_4 -> 'step_6' but if the condition isn't met, we don't want to invoke the step_2 lambda and would continue in the order of step_3 -> step_4 -> step_5 -> step_6

Every step in step function is invoking some different Lambda which are responsible to perform some different kind of tasks, every steps looks like the below mentioned step_n.

        const step_n = new LambdaInvoke(this, 'Step_Name', {
            lambdaFunction: stackMap['LambdaName::someMethod()'],
            inputPath: '$',
            outputPath: '$.Payload',
        });
      


const definition = step_1
            .next(new Choice(this, "RequestType", {
                    inputPath: '$'
                })
                    .when(Condition.stringEquals('$.requestType', 'OD3'), step_2
                        .next(step_3)
                        .next(step_4)
                        .next(step_6))
                    .otherwise(step_3
                        .next(step_4)
                        .next(step_5)
                        .next(step_6))
            );


        const stateMachine = new StateMachine(this, 'StateMachine', {
            definition
        });

I was able to remove the error by redefining by code like below :

        const choice = new Choice(this, "RequestType", {
            inputPath: '$'
        })
        const isOD3RequestCondition = Condition.stringEquals('$.requestType', 'OD3')

        const definition4 = step_4
            .next(choice.when(Condition.not(isOD3RequestCondition), step_5).afterwards())
            .next(step_6);
        const definition3 = step_1
            .next(choice.when(isOD3RequestCondition, step_2).afterwards())
            .next(step_3);
        const definition = definition3.next(definition4);

but while deploying the stacks I get the below error :

Resource handler returned message: "Invalid State Machine Definition: 'MISSING_END_STATE: Workflow has no terminal state at null' (Service: AWSStepFunctions; Status Code: 400; Error Code: InvalidDefinition; Request ID: 208ea192-645a-4ddf-9001-f5fdab0742

[peterwoodworth]

Hey, you've duplicated this issue both here and in our issue queue. I'm going to mark this as answered so that we can use the issue for a single place of discussion

[noddyStark]

Thank you!

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.