Show HN: Pure Effect – Reproduce production bugs on your laptop without a DB

Category: library

Tags: effect-system, testing, typescript, dependency-injection, async

Score: 6.8/10 (Innovation: 7, Technical: 6, Documentation: 8, Utility: 6)

Pure Effect is a tiny, zero-dependency JavaScript/TypeScript library for building async pipelines as plain data objects, enabling testing without mocks via composable primitives like Command, Retry, and Parallel. Its interesting approach treats business logic as inspectable values that can be asserted before execution, combined with built-in DI and OpenTelemetry hooks, making it a lightweight alternative to heavier effect systems.

Target audience: backend devs

Repository: https://pure-effect.org · JavaScript · MIT · 35 stars

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