Node aws sdk step function client is not picking up any configuration

Question

I am trying to write some Node code to create and execute a step function, but I have a problem in the way configuration is passed into the middleware that manages requests.

At its simplest, I can run stepfunctions-local in docker with the defaults

docker run -p 8083:8083 amazon/aws-stepfunctions-local

which means it is now running on port 8083. If I set up a dummy profile, I can then create a state machine from the CLI with

aws stepfunctions --endpoint http://localhost:8083 create-state-machine --definition "$(cat test.json)" --name test --role-arn "arn:aws:iam::012345678901:role/DummyRole" --region eu-west-1 --profile dummy

(my ~/.aws/credentials has the following entry)

[dummy]
aws_access_key_id = dummy
aws_secret_access_key = dummy

If I do the equivalent from node

    sfnLocalClient = new SFNClient([{
      endpoint: `http://localhost:8083`,
      region: 'eu-west-1',
      credentials: {
        accessKeyId: 'dummy',
        secretAccessKey: 'dummy',
      },
    }]);

    stateMachine = await sfnLocalClient.send(
      new CreateStateMachineCommand({
        name: 'TestStateMachine',
        roleArn: 'arn:aws:iam::012345678901:role/DummyRole',
        definition: readFileSync('test.json', 'utf8'),
      }));

It first fails due to missing region. If I set the region as an env variable it fails with no credentials provided. If I set the dummy profile as an env variable then it fails due to The security token included in the request is invalid.

Debugging a bit, I find the requests are going to a default state machine endpoint states.eu-west-1.amazonaws.com, so it seems like again my config is being ignored. Looking into this, I find various code to pull information out of the config ready to use in a stack of middleware implementations (defined in the SFNClient constructor in @aws-sdk/client-sfn).

I'm guessing they all have the same problem, but looking at the endpoint resolution in particular (@smithy/middleware-endpoint) the resolveEndpointConfig function tries to get configured endpoint as const { endpoint } = input; but when I look at input I see that my endpoint config is nested inside a property called o in the input hence it doesn't find it.

If I tamper with the code and change it to const endpoint = 'http://localhost:8080' then it successfully creates the state machine.

Does anyone know if I'm hitting a bug or if I'm doing something obviously wrong? I'm more of a Java engineer so please let me know if I've left out important information in this question that I can look up and add.

I'm specifying ^3.398.0 as the @aws-sdk/client-sfn version. I can dig into package-lock if it helps to find versions of the aws and smithy libraries.

UPDATE

It seems that runtimeConfig.js doesn't expect a tuple of config, but the SFNClient constructor does. I don't quite get the syntax, maybe that is my problem - SFNClient code looks like

constructor(...[configuration]: __CheckOptionalClientConfig<SFNClientConfig>);

@aws-sdk/client-sfn getRuntimConfig function puts together the config with

return {

        ...clientSharedValues,
        ...config,

which seems to include the first tuple entry as an object whereas it looks like it expects to just include the properties

Answer 1

Seems like the issue is with the IDE (Webstorm) that prompts me to include an array of Config objects. If I pass in just an object

    sfnLocalClient = new SFNClient({
      endpoint: `http://localhost:8083`,
      region: 'eu-west-1',
      credentials: {
        accessKeyId: 'dummy',
        secretAccessKey: 'dummy',
      },
    });

it gives me compilation error Argument type {endpoint: string, credentials: {accessKeyId: string, secretAccessKey: string}, region: string} is not assignable to parameter type __CheckOptionalClientConfig<SFNClientConfig>

But if I just run it, it all works perfectly.

This is a new world for me - in Java, I can't run code with compilation errors!