API Testing
Authentication is where most API bugs hide. A missing header, an expired token, an incorrect scope — any of these can silently break a protected endpoint in ways that unit tests never catch. REST Assured makes authentication testing straightforward, giving you the tools to verify not just that authenticated requests work,
API Testing
Okta is the identity layer for many enterprise applications. Testing Okta integrations is challenging because identity flows involve browser redirects, SAML assertions, multi-step authentication, and external callback URLs. But untested auth is the most dangerous untested code — a broken login means no users can access your application. This guide
API Testing
AWS Cognito provides user authentication, authorization, and identity management for AWS-hosted applications. Testing Cognito integrations is critical — a misconfigured user pool can lock users out, a broken Lambda trigger can block all signups, and a wrong JWT audience claim can silently reject valid users. This guide covers testing Cognito
Supabase
Supabase Auth combines JWT issuance, session management, email confirmation, OAuth, and Row Level Security into a single system. Testing each layer in isolation — and then together — catches bugs that only appear at the boundaries. This guide covers unit testing with mocked supabase-js, integration testing against a local Supabase instance,
Testing
NextAuth.js v5 (now called Auth.js) is a significant rewrite that embraces Next.js App Router and Edge runtime. Testing Auth.js v5 apps is different from v4 — there's no more getServerSideProps, sessions are handled via auth() from the server, and the middleware approach changed. This guide
Testing
Clerk is a popular authentication platform that handles sign-up, sign-in, user management, and session management for you. Testing Clerk-authenticated apps is non-trivial because Clerk wraps your app in providers and its hooks make real API calls. This guide shows you how to test Clerk integrations without
Testing
BetterAuth is a newer authentication library for TypeScript that emphasizes type safety, a plugin system, and framework agnosticism. It's built for modern full-stack frameworks (Next.js, SvelteKit, Astro, Hono) and supports a wide range of social providers out of the box. Testing BetterAuth integrations means testing its
Testing
Lucia Auth is a lean, framework-agnostic authentication library for TypeScript that gives you full control over session management. Unlike Clerk or Auth0, Lucia is not a SaaS — it runs on your infrastructure and stores sessions in your database. This ownership makes testing more thorough because you can actually inspect
Testing
Choosing an auth provider is a long-term architectural decision, and your test strategy should make switching providers feasible if your needs change. This guide compares how Clerk, Auth0, and Supabase Auth work in integration tests, and shows how to structure your tests so the auth provider is an implementation
Testing
OAuth2 integrations are painful to test in CI because the authorization code flow requires a browser and human interaction. This guide covers how to test OAuth2 without browser automation: mocking the token exchange, testing the callback handler, validating token storage, testing refresh flows, and running full browser-based auth tests
Security Testing
Authentication is the most critical security boundary in any web application. Broken authentication is consistently in the OWASP Top 10 because the implementation surface is enormous — JWTs, OAuth2 flows, session tokens, password reset flows, MFA. Each component can fail independently. This guide covers how to test each layer systematically. Key
Testing
Testing authenticated APIs is unavoidable in any real project. Most production endpoints require authentication — Basic Auth, Bearer tokens, OAuth2, or API keys. REST Assured provides built-in support for common authentication schemes and the flexibility to handle anything custom. This guide covers the patterns you'll actually use. Basic