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The Serverless Workflow Conformance Test Kit (CTK) is a suite of automated tests designed to ensure that implementations of the Serverless Workflow specification conform to the standard. The CTK is composed of multiple Gherkin features, each representing various aspects of the Serverless Workflow DSL.

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What is Gherkin?

Gherkin is a human-readable language used for writing structured tests, which can be understood by both non-technical stakeholders and automated test frameworks. It uses a Given-When-Then syntax to describe the preconditions, actions, and expected outcomes of a test scenario.

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Example Scenario

Feature: HTTP Task Execution
  As a workflow developer
  I want to call HTTP endpoints
  So that I can integrate with external services

  Scenario: Simple GET request
    Given a workflow with definition:
    """
    document:
      dsl: 1.0.0
      namespace: test
      name: http-test
      version: 1.0.0
    do:
      - fetchData:
          call: http
          with:
            method: get
            uri: https://api.example.com/data
    """
    When the workflow is executed
    Then the workflow should complete

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Primary Uses

The Serverless Workflow CTK serves two primary purposes:

Conformance Testing

Verify that implementations adhere to the Serverless Workflow specification

Behavior-Driven Development

Facilitate collaborative development using Gherkin scenarios

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Benefits

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For Runtime Implementers

  • Validation: Ensure your runtime correctly implements the specification
  • Regression Testing: Catch breaking changes early in development
  • Documentation: Use test scenarios as implementation examples
  • Confidence: Demonstrate spec compliance to users

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For SDK Developers

  • Verification: Validate workflow parsing and validation logic
  • Compatibility: Ensure workflows work across different runtimes
  • Quality: Maintain high standards for workflow definitions

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For Workflow Authors

  • Understanding: Learn DSL features through concrete examples
  • Validation: Test workflow definitions against expected behavior
  • Portability: Ensure workflows work across compliant runtimes

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Test Structure

The CTK organizes tests using the Arrange-Act-Assert pattern:

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Arrange

Sets up the initial conditions for the test: 
Given a workflow with definition:
"""
yaml
<WORKFLOW_DEFINITION>
"""
And given the workflow input is:
"""
yaml
<INPUT_DATA>
"""

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Act

Performs the action being tested: 
When the workflow is executed

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Assert

Verifies the expected outcome: 
Then the workflow should complete
And the workflow output should have a 'result' property with value:
"""
yaml
status: success
"""

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Getting Started

To start using the CTK:

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1. Clone the Repository

git clone https://github.com/serverlessworkflow/specification.git
cd specification/ctk

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2. Review Available Features

Explore the test features in the /ctk/features directory: 
ls features/
# call-http.feature
# call-grpc.feature
# data-flow.feature
# error-handling.feature
# ...

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3. Implement Step Definitions

Create step definitions in your preferred language and testing framework to execute the Gherkin scenarios against your implementation.

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4. Run the Tests

Execute the test suite using your chosen test runner.

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Test Coverage

The CTK covers all major aspects of the Serverless Workflow DSL:
  • Task execution (HTTP, gRPC, OpenAPI, AsyncAPI)
  • Data flow and transformation
  • Error handling and retries
  • Event processing
  • Control flow (conditional, parallel, iterative)
  • Timeouts and cancellation
  • Subflow execution
  • Extension points

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Contributing

The CTK is continuously evolving. Contributions are welcome:
  • Add Test Scenarios: Expand coverage for edge cases
  • Improve Documentation: Clarify test intent and expectations
  • Report Issues: Identify gaps or ambiguities in tests
  • Share Implementations: Contribute step definitions for different languages

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Resources

Conformance Testing Guide

Learn how to validate your implementation

BDD Guide

Use the CTK for Behavior-Driven Development

GitHub Repository

Access the complete test suite

Community Slack

Get help on #serverless-workflow

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