Is it useful for testing concurrent code?

Yes, it includes specialized patterns for testing race conditions, parallel execution, and atomic operations using Refs and Fibers.

Does this skill support the Vitest framework?

Yes, it specifically focuses on @effect/vitest integration, providing patterns for it.effect, it.layer, and it.scoped to handle TestContext and dependencies.

How does it help with service mocking?

It provides standardized patterns for creating mock layers using Layer.succeed and Layer.mock, allowing for partial or full implementation of service dependencies.

Can I test time-based effects without waiting?

Absolutely. This skill includes patterns for using TestClock to adjust time manually, allowing you to test delays and schedules instantly.

Effect-TS Testing Patterns

Name: Effect-TS Testing Patterns
Author: enitrat

byenitrat

•

Security & Testing

Provides standardized patterns and best practices for writing comprehensive tests for Effect-TS applications and services.

This skill equips Claude with specialized knowledge for testing Effect-TS codebases, covering everything from basic effect testing with Vitest to complex scenarios like clock manipulation and layer mocking. It ensures that developers follow best practices for service dependency injection in tests, error handling verification, and resource management within a functional programming context. By using this skill, Claude can generate production-grade test suites that handle concurrency, streams, and environment configurations efficiently while ensuring high reliability in functional TypeScript projects.

Key Features

01Patterns for testing complex effects including Streams, HTTP clients, and ConfigProviders

02@effect/vitest integration with it.effect, it.layer, and it.scoped

038 GitHub stars

04Comprehensive error testing for expected failures, multiple types, and defects

05Time-travel testing and determinism using TestClock and TestRandom

06Advanced service mocking strategies using Layer.succeed and Layer.mock

Use Cases

01Generating unit tests for complex Effect-TS services with multiple nested dependencies

02Verifying error handling paths and pattern matching on custom tagged errors

03Simulating time-dependent logic and intervals without waiting using virtual clocks

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add enitrat/skill-issue effect-testing

For use in Claude.ai and ChatGPT

Download Skill