Local testing of CDK-defined Step Functions state machine

This presentation describes the different pieces of the puzzle needed to unit test a Step Functions state machine defined with CDK code.

Transcript

1. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   Jerome Van Der Linden (@jeromevdl)
   Automate Local Testing of CDK-defined
   Step Functions
   Solutions Architect Builder @ AWS
   

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2. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   Who am I ?
   Jérôme Van Der Linden
   Solutions Architect Builder @ AWS (Geneva, Switzerland)
   Former consultant, developer, tech lead, agile & devops
   coach, architect @ OCTO Technology
   Husband and Dad of 3
   jeromevdl
   

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3. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   Objec8ves
   • Unit testing AWS Step Functions State Machines
   • Defined with CDK code
   • Locally without reaching the cloud
   • Automate as much as possible the process
   

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4. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   Big Picture
   

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5. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   Big Picture
   

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6. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   CDK-defined Step Functions State Machine
   

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7. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   CDK-defined Step Functions State Machine
   

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8. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
   CDK-defined Step Functions State Machine
   

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   CDK Deploy
   

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    CDK Deploy
    Since I recorded this video, I
    discovered cdk-asl-extractor
    It permits to retrieve the ASL without
    deploying the stack. 😀🤩
    Use cdk synth to get the
    CloudFormation template
    and use cdk-asl-extractor
    to get the ASL from the template.
    

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11. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Outputs
    🌀🌩☠
    ❗💥🤯
    output.json
    Stack name Output name Randomly generated string
    Construct
    name
    

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    Extracting the State Machine definition
    Rocks!
    

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    State Machine definition
    state_machine.asl.json
    

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    Wrap-up: CDK code to JSON ASL
    

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15. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Mocked service integration
    MockConfigFile.json
    State Machine name
    Mocked states
    Mocked responses names
    Mocked responses definitions
    

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16. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Step Func8ons Local
    Start stepfunctions-local:
    Mocked Configuration
    

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17. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Step Functions Local
    Create the state machine locally:
    State machine definition
    (ASL / JSON)
    State Machine name
    (same as in the MockConfigFile.json)
    

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    Wrap-up: Step-Func8ons local bootstrap
    

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    Unit Tests
    State Machine name
    (same as in the MockConfigFile.json)
    Test case name
    (same as in the MockConfigFile.json)
    Local endpoint
    

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    Unit Tests
    Test case name
    (same as in the MockConfigFile.json)
    

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    Wrap-up
    

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    Wrap-up
    1. Retrieve the state machine ASL
    from the CDK code
    

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23. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Wrap-up
    1. Retrieve the state machine ASL
    from the CDK code
    2. Create Mocked Service
    integration config
    

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24. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Wrap-up
    1. Retrieve the state machine ASL
    from the CDK code
    2. Create Mocked Service
    integration config
    3. Start Step Functions local with
    this mocked configuration
    4. Create a State Machine locally
    

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25. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Wrap-up
    1. Retrieve the state machine ASL
    from the CDK code
    2. Create Mocked Service
    integration config
    3. Start Step Functions local with
    this mocked configuration
    4. Create a State Machine locally
    5. Run your tests (using the SDK)
    

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26. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Wrap-up
    1. Retrieve the state machine ASL
    from the CDK code
    2. Create Mocked Service
    integration config
    3. Start Step Functions local with
    this mocked configuration
    4. Create a State Machine locally
    5. Run your tests (using the SDK)
    

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27. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Resources
    

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28. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    • Testing Step Functions State Machines Locally
    • https://docs.aws.amazon.com/step-functions/latest/dg/sfn-local.html
    • Using Mocked Service Integrations
    • https://docs.aws.amazon.com/step-functions/latest/dg/sfn-local-test-sm-exec.html
    • Mocking service integrations with AWS Step Functions Local
    • https://aws.amazon.com/blogs/compute/mocking-service-integrations-with-aws-step-functions-local/
    • Code Sample GitHub
    • https://github.com/aws-samples/step-functions-direct-integrations/tree/main/direct-integration/infra
    

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29. © 2022, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved. Amazon Confidential and Trademark
    Thank you
    jeromevdl
    Jérôme Van Der Linden
    

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