Effect Learning Exercises

A progressive, hands-on course for learning Effect from basic concepts to advanced patterns, inspired by Exercism.

🎯 What is This?

This project contains 47 learning exercises divided into 15 levels, covering all core Effect concepts through practical, test-driven assignments.

Unlike tutorials or documentation, this is a structured learning path where you:

• ✅ Write real code, not just read examples
• ✅ Get instant feedback from automated tests
• ✅ Compare your solutions with reference implementations
• ✅ Progress from basics to advanced patterns systematically

📚 What You'll Learn

• ✅ Basics - creating, running, transforming Effects
• ✅ Error Handling - typed errors, catching, fallback strategies
• ✅ Control Flow - conditionals, loops, combining effects
• ✅ Concurrency - Fibers, racing, parallel execution
• ✅ Resource Management - Scope, acquire/release patterns
• ✅ Services & Layers - Dependency Injection the Effect way
• ✅ State Management - Ref, SynchronizedRef, SubscriptionRef
• ✅ Advanced Concurrency - Deferred, Queue, PubSub, Semaphore
• ✅ Streams & Sink - processing data streams
• ✅ Scheduling & Caching - retry policies, caching strategies
• ✅ Batching & Requests - optimizing request patterns
• ✅ Observability - Logging, Metrics, Tracing
• ✅ Configuration & Runtime - managing app configuration
• ✅ Advanced Patterns - Interruption, Supervision, Effect.gen

🚀 Quick Start

Installation

# Clone the repository
git clone https://github.com/yourusername/effect-learn.git
cd effect-learn

# Install dependencies
npm install
# or
pnpm install
# or
bun install

Your First Exercise

1. Read the guide:

cat exercises/GUIDE.md

2. Start with Level 1:

cd exercises/01-basics/01-creating-effects
cat README.md

3. Implement the functions in exercise.ts

4. Run the tests:

npm test exercises/01-basics/01-creating-effects

5. Compare with solution if stuck:

cat solution.ts

📖 Structure

exercises/
├── 01-basics/              # Level 1: Basics (3 exercises)
├── 02-error-handling/      # Level 2: Error Handling (3 exercises)
├── 03-control-flow/        # Level 3: Control Flow (3 exercises)
├── 04-concurrency/         # Level 4: Concurrency (3 exercises)
├── 05-resource-management/ # Level 5: Resource Management (2 exercises)
├── 06-services/            # Level 6: Services (3 exercises)
├── 07-state-management/    # Level 7: State Management (3 exercises)
├── 08-advanced-concurrency/# Level 8: Advanced Concurrency (4 exercises)
├── 09-streams/             # Level 9: Streams (4 exercises)
├── 10-sink/                # Level 10: Sink (2 exercises)
├── 11-scheduling-caching/  # Level 11: Scheduling & Caching (3 exercises)
├── 12-batching-requests/   # Level 12: Batching (2 exercises)
├── 13-observability/       # Level 13: Observability (3 exercises)
├── 14-configuration-runtime/# Level 14: Configuration (3 exercises)
├── 15-advanced-patterns/   # Level 15: Advanced Patterns (3 exercises)
├── EXERCISES.md            # Complete list of exercises
├── GUIDE.md                # Usage guide
└── test-utils.ts           # Testing utilities

Each Exercise Contains:

• 📝 README.md - concept explanation and assignment
• 💻 exercise.ts - your solution file
• ✅ solution.ts - reference solution
• 🧪 exercise.test.ts - automated tests

🧪 Commands

# Run all tests
npm test

# Run specific exercise tests
npm test exercises/01-basics/01-creating-effects

# Watch mode
npm test -- --watch

# Coverage report
npm run coverage

# Type checking
npm run check

# Build
npm run build

📝 How to Work with Exercises

1. Read README.md - understand the concept
2. Implement exercise.ts - write your code
3. Run tests - verify your solution
4. Compare with solution.ts - if you're stuck
5. Track progress - mark completed in EXERCISES.md

🎯 Recommended Learning Path

Exercises are organized by increasing difficulty:

1. Beginners: Levels 1-3 (Basics, Errors, Control Flow) - ✅ Fully Ready
2. Intermediate: Levels 4-6 (Concurrency, Resources, Services)
3. Advanced: Levels 7-15 (State, Streams, Observability, etc.)

🌟 Features

• 🎯 Progressive Learning - from simple to complex
• 📝 Detailed Explanations - concept + examples + hints
• ✅ Automated Tests - instant feedback
• 🎓 Reference Solutions - learn best practices
• 🛠️ CLI Tools - convenient exercise management
• 📚 Complete Documentation - guides and resources

📊 Current Status

• ✅ Levels 1-3: Fully ready with detailed content (9 exercises)
• 📝 Levels 4-15: Basic structure ready to fill (38 exercises)

See PROJECT_STATUS.md for details.

📚 Additional Resources

• 📖 Effect Documentation - official docs
• 💬 Effect Discord - community chat
• 🐙 Effect GitHub - source code
• 📝 Effect Blog - articles and tutorials
• 🎥 Effect YouTube - video content

🤝 Contributing

Found a bug or want to improve an exercise? Contributions are welcome!

1. Fork the repository
2. Create your feature branch
3. Make your changes
4. Submit a pull request

See CONTRIBUTING.md for details.

📄 License

MIT © [Your Name]

---

Happy learning Effect! 🚀

If you find this useful, please ⭐ star the repository and share it with others!