Free to read ยท Three levels
API Testing: contracts, isolation, and evidence
A complete course on turning API promises into interpretable tests for boundaries, errors, compatibility, and business effects.
Start learningIn this course
Follow a fictional book catalog and reading list from a requirement to a review decision. Basic lessons build independent oracles, HTTP expectations, JSON boundaries, isolated fixtures, and useful refusal contracts. Cases examine both the visible response and the protected state.
Intermediate lessons connect schemas to consumers, permissions to resources, pages to ordering, retries to effects, writes to preconditions, and asynchronous work to bounded terminal observations. Advanced lessons develop properties, consumer interactions, diagnostics, offline performance reasoning, CI selection, and a versioned evidence package.
The English and Arabic versions preserve identifiers, examples, and results with complete teaching in each language. Complete standard-library programs operate locally in memory; schema data and HTTP fragments remain non-runnable illustrations. No real service, credential, network target, or dependency installation is required.
What you will learn
- Write independent promises, oracles, and fixtures.
- Check representations, refusals, ownership, ordering, replay, and transitions.
- Interpret compatibility, performance, and diagnostics within evidence limits.
- Present execution inventories and conclusions that preserve unresolved questions.
Your learning path
Three levels
Basic: trustworthy API observations
Build explicit contracts, request/response assertions, JSON boundaries, isolated fixtures, and safe error evidence.
- Turn an API promise into testable evidence
- Test HTTP responses as structured contracts
- Test JSON boundaries and representation choices
- Write assertions that explain the broken promise
- Build isolated fixtures and deterministic tests
- Verify error contracts and unchanged state
Intermediate: interacting contracts
Connect schemas, access policies, collections, retries, conditional writes, and asynchronous workflows.
- Test schemas and directional compatibility
- Test authentication and authorization matrices
- Test pagination, filtering, and stable order
- Test retries and duplicate suppression
- Test conditional updates and lost-update prevention
- Test asynchronous workflows with bounded observations
Advanced: versioned evidence and review
Use properties, consumer interactions, diagnostics, performance reasoning, CI selection, and traceability without unsupported deployment claims.
- Test properties and metamorphic relations
- Test the consumer-provider boundary
- Build failure evidence that preserves context
- Interpret API performance evidence offline
- Make CI selection and results auditable
- Review a versioned API evidence package
Who this is for
- Developers and quality engineers who want to review API contracts precisely.
- Learners who need to distinguish local policy evidence from deployment verification.
Before you start
- Basic familiarity with HTTP methods, JSON, and programming functions.
- Ability to read short Python programs; optional validation uses already available tools only.