tooling-hello-world.mdx

title	Set Up Your Effect Development Environment
id	tooling-hello-world
skillLevel	beginner
applicationPatternId	tooling-and-debugging
summary	Configure your editor and tools for the best Effect development experience.
tags	tooling setup vscode getting-started
rule	description Install the Effect extension and configure TypeScript for optimal Effect development.
author	PaulJPhilp
related	tooling-effect-lsp getting-started-hello-world
lessonOrder	2

Guideline

Set up your development environment with the Effect extension and proper TypeScript configuration for the best experience.

---

Rationale

A well-configured environment helps you:

1. See types clearly - Effect types can be complex
2. Get better autocomplete - Know what methods are available
3. Catch errors early - TypeScript finds problems
4. Navigate easily - Go to definitions, find references

---

Setup Steps

1. Install Effect

# Using Bun (recommended)
bun add effect

# Or npm
npm install effect

# Or pnpm
pnpm add effect

2. Configure TypeScript

Create or update tsconfig.json:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "strict": true,
    "exactOptionalPropertyTypes": true,
    "noUncheckedIndexedAccess": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "declaration": true,
    "sourceMap": true
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules"]
}

3. Install VS Code Extensions

Install the Effect extension for VS Code:

1. Open VS Code
2. Go to Extensions (Cmd+Shift+X)
3. Search for "Effect"
4. Install the official Effect extension

The extension provides:

• Better type display (unwraps complex Effect types)
• Quick fixes and refactorings
• Inline error previews
• Go to definition for Effect functions

4. VS Code Settings (Optional)

Add to .vscode/settings.json for better Effect experience:

{
  "typescript.preferences.includePackageJsonAutoImports": "on",
  "typescript.inlayHints.functionLikeReturnTypes.enabled": true,
  "typescript.inlayHints.parameterTypes.enabled": true,
  "editor.formatOnSave": true
}

---

Verify Setup

Create a test file to verify everything works:

// src/hello.ts
import { Effect, Console } from "effect"

const program = Effect.gen(function* () {
  yield* Console.log("Effect is working!")
  return 42
})

// Hover over 'result' - should show: Effect<number, never, never>
const result = program

// Run it
Effect.runPromise(result).then(console.log)

Run it:

bun src/hello.ts
# Output: Effect is working!
# Output: 42

---

Key Editor Features

Feature	How to Use
Hover for types	Hover over any variable
Go to definition	Cmd+Click on a function
Find references	Right-click → Find All References
Autocomplete	Type . after an Effect
Quick fix	Click lightbulb or Cmd+.

---

Project Structure

Recommended structure for Effect projects:

my-project/
├── src/
│   ├── index.ts       # Entry point
│   ├── services/      # Effect services
│   ├── errors/        # Tagged errors
│   └── utils/         # Helper functions
├── test/
│   └── *.test.ts      # Tests
├── package.json
└── tsconfig.json

---

Next Steps

1. Try the Getting Started patterns
2. Install the Effect LSP for advanced features
3. Explore the Effect documentation