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
Testing
Deno ships with a built-in test runner. No configuration, no separate test framework, no package.json scripts to set up. Run deno test and you're testing. This guide covers everything in Deno's testing toolkit: Deno.test, the standard assertion library, subtests, test filtering, code coverage,
Testing
Deno's standard library provides @std/mock for test doubles — spies, stubs, and fake timers. These let you isolate units under test from their dependencies without external mocking libraries. This guide covers everything in @std/mock: spying on function calls, stubbing module methods, mocking fetch, and controlling time in
Testing
Deno KV is a key-value store built into the Deno runtime. In development, it uses SQLite. In Deno Deploy, it uses FoundationDB. Testing KV code correctly means understanding both the API and how to isolate tests from each other. This guide covers testing Deno KV: CRUD operations, atomic transactions,
Testing
Integration tests verify that your Deno application's components work together — that HTTP routes return the right responses, that database queries return the right data, that error handling works end-to-end. They bridge the gap between unit tests (which verify logic in isolation) and E2E tests (which run
Testing
Deno Fresh is a full-stack framework built on Deno, Preact, and server-side rendering. It follows a "no build step" philosophy — components render on the server by default, and interactive parts (called Islands) hydrate on the client. Testing Fresh apps covers three areas: 1. Route handlers — the