QE Contract Testing

QE Contract Testing

Purpose

Guide the use of v3's contract testing capabilities including consumer-driven contracts, schema validation, backward compatibility checking, and API versioning verification.

Activation

• When testing API contracts
• When validating schema changes
• When checking backward compatibility
• When testing GraphQL APIs
• When verifying event schemas

Quick Start

# Generate contract from API
aqe contract generate --api openapi.yaml --output contracts/

# Verify provider against contracts
aqe contract verify --provider http://localhost:3000 --contracts contracts/

# Check breaking changes
aqe contract breaking --old api-v1.yaml --new api-v2.yaml

# Test GraphQL schema
aqe contract graphql --schema schema.graphql --operations queries/

Agent Workflow

// Contract generation
Task("Generate API contracts", `
  Analyze the REST API and generate consumer contracts:
  - Parse OpenAPI specification
  - Identify critical endpoints
  - Generate Pact contracts
  - Include example requests/responses
  Output to contracts/ directory.
`, "qe-api-contract")

// Breaking change detection
Task("Check API compatibility", `
  Compare API v2.0 against v1.0:
  - Detect removed endpoints
  - Check parameter changes
  - Verify response schema changes
  - Identify deprecations
  Report breaking vs non-breaking changes.
`, "qe-api-compatibility")

Contract Testing Types

1. Consumer-Driven Contracts (Pact)

await contractTester.consumerDriven({
  consumer: 'web-app',
  provider: 'user-service',
  contracts: 'contracts/web-app-user-service.json',
  verification: {
    providerBaseUrl: 'http://localhost:3000',
    providerStates: providerStateHandlers,
    publishResults: true
  }
});

2. Schema Validation

await contractTester.validateSchema({
  type: 'openapi',
  schema: 'api/openapi.yaml',
  requests: actualRequests,
  validation: {
    requestBody: true,
    responseBody: true,
    headers: true,
    statusCodes: true
  }
});