Testing
Inngest is a serverless background job platform that runs durable functions via event triggers. Unlike traditional job queues, Inngest functions are composable: each step.run is a discrete, retriable unit. Testing this architecture requires understanding how Inngest executes functions and where your logic actually lives. How Inngest Executes Functions Inngest
Testing
BullMQ's advanced features — flow producers, delayed jobs, rate limiters, and job groups — enable sophisticated background processing patterns. But these features are also the hardest to test correctly. This guide covers testing strategies for each advanced BullMQ pattern, building on basic queue testing to handle the complex orchestration scenarios
Testing
Reasoning models — OpenAI's o3/o4-mini, Anthropic's Claude with extended thinking, and DeepSeek R1 — require different evaluation strategies than standard language models. They trade token budget for reasoning quality, produce verifiable intermediate steps, and have different failure modes. This guide covers building eval frameworks specifically for reasoning
Testing
DeepSeek R1 is an open-weight reasoning model that exposes its chain-of-thought reasoning as a <think> block before the final answer. This transparency makes it uniquely testable — you can evaluate not just whether the answer is correct, but whether the reasoning process is sound. This guide covers testing strategies
Testing
Gemini 2.5 Pro is Google's most capable model in 2026, with native multimodal input (images, audio, video, documents), a 2-million-token context window, and an optional "thinking" mode for complex reasoning. Testing Gemini 2.5 integrations requires eval patterns that account for these unique capabilities. This
Testing
Anthropic's Computer Use API lets Claude control a computer — clicking, typing, scrolling, and taking screenshots — to complete tasks autonomously. Testing Computer Use integrations is uniquely challenging because you're testing an agentic system that interacts with a real or simulated UI. This guide covers testing strategies for
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 hitting Clerk's
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 plugin
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 the
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 detail,
Testing
Apollo Client is the most widely used GraphQL client for React, and testing it properly means going beyond shallow component tests. You need to verify that your components handle loading states, successful data responses, error states, and cache interactions correctly. Apollo provides MockedProvider for exactly this purpose — this guide shows