API testing guides — test REST and GraphQL APIs, write contract tests, and automate API validation.
Supertest
Supertest works well for standard request-response APIs, but streaming responses — chunked transfers, Server-Sent Events, NDJSON — need extra handling. This post covers how to test streaming endpoints in Node.js using Supertest's lower-level API and, when needed, raw HTTP clients. Key Takeaways Supertest can handle streaming
Supertest
An OpenAPI spec is a contract. When your API response drifts from the spec — a field renamed, a type changed, a required property missing — clients break silently. Supertest combined with schema validation lets you assert that every API response matches the contract, automatically, on every test run. Key Takeaways Validate
Supertest
Authentication bugs are the most expensive bugs to ship. Supertest lets you test the entire JWT lifecycle — login, token issuance, protected route access, refresh, and revocation — at the HTTP layer, exactly as a real client would interact with your API. Key Takeaways Test authentication at the HTTP boundary. Mocking JWT
Supertest
Express middleware sits between the HTTP request and your route handlers — and it's where security headers, rate limits, request validation, and error formatting live. Supertest lets you test middleware in two ways: in isolation on a minimal app, or integrated into your full application stack. Both matter. Key
API Testing
Postman has become synonymous with API testing for many developers. SoapUI has been the enterprise standard for SOAP services for over a decade. If you are choosing between them — or wondering whether you need both — this comparison will give you a clear answer. The short version: Postman wins for REST
API Testing
Static SOAP tests — send a request, assert a response — cover the basics. But real-world testing requires dynamic behavior: generating unique values, extracting data from one response to use in the next request, conditional logic based on response content, and loops. SoapUI's Groovy scripting engine handles all of
API Testing
SOAP and REST are both ways to expose functionality over a network. They look superficially similar — both use HTTP, both exchange data between a client and server — but the differences run deep, and those differences change how you test them completely. If you are inheriting a SOAP codebase, moving from
API Testing
Your OpenAPI spec describes what your API should accept and return. But without enforcement, it's just documentation — developers drift, inputs go unvalidated, and responses gradually diverge from what consumers expect. express-openapi-validator is middleware that makes your OpenAPI spec executable. It validates every incoming request and outgoing
Snapshot Testing
Snapshot testing is commonly associated with React components, but it's equally useful for API responses. A snapshot of an API response documents the expected contract — the exact shape, field names, and values that callers depend on. When the response changes unexpectedly, the snapshot fails. This guide covers applying
Testing Strategy
API breaking changes discovered in production cost orders of magnitude more than those caught at PR time. Shifting API testing left means validating contracts, schemas, and behaviors before code merges — using consumer-driven contracts, mock servers, and OpenAPI-first workflows that integrate directly into your CI pipeline. Key Takeaways Consumer-
Testing
Serenity BDD includes built-in REST API testing support via the serenity-rest-assured module. It wraps REST Assured with Serenity's reporting engine, so API tests produce the same structured HTML reports as browser tests — step details, request/response logs, and requirements traceability. Setup <dependency> <
BDD
Serenity BDD integrates with REST Assured to give you the same rich HTML reports for API tests that you get for UI tests. Combine this with Cucumber and you can write acceptance tests that mix API calls and browser interactions in a single scenario — useful for tests that need to