CONTRIBUTING.md

Contributing to @effectorhq/core

Thank you for your interest in contributing!

Development Setup

git clone https://github.com/effectorHQ/effector-core.git
cd effector-core
npm test  # 100+ tests, zero dependencies

Guidelines

• Zero dependencies. All code uses only Node.js built-ins. No exceptions.
• ES Modules only. All files use import/export.
• Node 18+. We use parseArgs, import.meta.url, etc.
• Tests required. Every new function needs tests. Run node --test tests/*.test.js.
• TypeScript declarations. Update the corresponding .d.ts when changing a function signature.

Project Structure

src/
  index.js              Barrel export
  toml-parser.js        effector.toml parser (section-aware)
  skill-parser.js       SKILL.md parser (YAML + Markdown)
  type-checker.js       Type compatibility engine (36 bundled types)
  schema-validator.js   Manifest validation
  compiler-targets.js   Cross-runtime compiler (MCP, OpenAI, LangChain, JSON)
  effector.js           Fluent builder API
  errors.js             Structured error types
  cli.js                CLI binary
  types-catalog.json    Bundled 40-type catalog
  *.d.ts                TypeScript declarations

Adding a New Compile Target

Use the plugin system instead of modifying the built-in switch:

import { registerTarget } from '@effectorhq/core';

registerTarget('my-runtime', (def) => {
  return JSON.stringify({ name: def.name, ... });
}, { description: 'My runtime format', format: 'json' });

If you believe a target should be built-in, open an issue first.

Pull Request Process

1. Fork and create a branch
2. Write code + tests
3. Run npm test — all tests must pass
4. Run npm run lint — all files must parse
5. Submit PR with a clear description

Code Style

• 2-space indentation
• Single quotes for strings
• Semicolons required
• JSDoc for all exported functions
• Descriptive variable names