Testing
Mixpanel powers product analytics for funnels, retention, and segmentation. Testing Mixpanel integrations requires mocking the SDK, validating event schemas against your Lexicon, testing people property updates, and isolating test environments so CI events don't corrupt your production data. This guide covers all of this with practical Jest examples
DevOps
Crossplane Compositions map abstract claims (XR) to concrete managed resources. A bug in patch-and-transform logic can create the wrong resources or delete existing ones when a new claim is submitted. crossplane beta render validates Composition logic locally without touching a real Kubernetes cluster. uptest runs integration tests that create and
Testing
MailHog is the classic local SMTP catcher—simple, lightweight, widely used, and no longer maintained. Mailpit is its modern replacement: faster, ARM-native, with a cleaner API and better CI support. Mailtrap is the cloud-hosted option with spam analysis and team collaboration. This comparison covers all three so you can pick
Testing
Mailtrap's Email Testing API lets you write real assertions against captured emails in Node.js—subject line, HTML body, attachments, spam score—without sending anything to real inboxes. This guide shows how to integrate Mailtrap into Jest tests and CI pipelines so every code path that sends email
DevOps
AWS CDK generates CloudFormation templates from TypeScript, Python, or Java code. The CDK Assertions library lets you test the generated template — verifying resource configurations without deploying anything. CDK snapshot tests catch unintended template changes. CDK integ tests validate actual deployments in real AWS accounts. Together, these three patterns give you
Testing
PostHog combines product analytics, feature flags, session recording, and A/B testing in one platform. Testing PostHog integrations requires more than mocking — you need to test feature flag evaluation, verify event tracking, and ensure session recording is properly configured without capturing sensitive data. This guide covers all three layers with
AI Testing
Eval-driven development (EDD) applies the discipline of TDD to LLM application development. Instead of writing unit tests for deterministic code, you write evals that define what "good" looks like for your AI — before building the feature. Failing evals are your spec. This guide covers how to structure evals
Supabase
Row Level Security is one of Supabase's most powerful features — and one of the most dangerous to get wrong. A misconfigured RLS policy can silently expose every row in a table to every authenticated user, or lock out legitimate access entirely. Neither failure is obvious until something goes
Supabase
Supabase Realtime sits on top of Phoenix Channels over WebSocket. Testing it means dealing with asynchronous event delivery, connection lifecycle (SUBSCRIBED, CHANNEL_ERROR, CLOSED), and timing-sensitive state — exactly the conditions that produce flaky tests. This guide covers unit testing with a mocked Realtime client, integration testing postgres_changes events against
Supabase
Supabase Edge Functions run on Deno Deploy — a V8-isolate runtime that is fast to cold-start and strict about permissions. Testing them requires understanding three distinct layers: unit tests for your business logic, integration tests against a local Supabase instance, and end-to-end tests that hit the deployed function through its HTTP
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, JWT
TypeORM
```tldr TypeORM testing spans two distinct strategies: fast unit tests that mock the DataSource and repositories, and slower but trustworthy integration tests that run against a real database. This post walks through both approaches — from validating entity schemas with in-memory SQLite to spinning up PostgreSQL with TestContainers — and gives you