What should I test in an API?

Minimum: happy path, authentication, error handling. Better: validation, edge cases, performance. Complete: security testing, integration scenarios, chaos testing.

How do I handle test data?

Options: dedicated test environment, data factories, database seeding, test data management tools. Avoid: using production data (privacy), hardcoded test IDs (brittleness).

Should API tests be in CI/CD?

Yes, especially functional and integration tests. Fast feedback on every change. Performance tests can be separate (longer running). Security tests in CI or separately.

What is contract testing?

Verifying API consumer and provider agree on the contract (request/response format). Tools: Pact. Catches breaking changes. Valuable for microservices and third-party integrations.

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API Testing

Testing APIs to ensure they function correctly, handle errors gracefully, perform adequately, and are secure.

In-Depth Explanation

API testing validates that APIs work correctly, handle edge cases, perform acceptably, and are secure. It's faster and more stable than UI testing, making it ideal for CI/CD pipelines.

Testing types:

Functional: Correct responses for valid requests
Validation: Input validation, error handling
Integration: API interactions with other systems
Performance: Response times, throughput
Security: Authentication, authorisation, injection

Key test scenarios:

Happy path (valid inputs → expected outputs)
Invalid inputs (validation errors)
Authentication/authorisation failures
Edge cases (empty, null, maximum values)
Error conditions (timeouts, failures)

Testing tools:

Postman (manual and automated)
REST Assured (Java)
pytest + requests (Python)
Jest/Supertest (JavaScript)
k6, JMeter (performance)

Business Context

API testing catches issues early, before they affect users, and enables confident deployments with automated test suites.

How Clever Ops Uses This

We build comprehensive API test suites for Australian businesses, ensuring reliable APIs through automated testing in CI/CD pipelines.

Example Use Case

"An automated test suite validating all API endpoints: authentication flows, CRUD operations, error responses, and performance benchmarks - running on every commit."

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