Event Loop Testing and Examples

This repository contains a comprehensive collection of examples demonstrating various aspects of the JavaScript/Node.js Event Loop, focusing on the execution order of different types of operations including I/O, timers, microtasks, and process events.

📚 Project Structure

🎯 Purpose

This project serves as a practical demonstration of the Node.js Event Loop's behavior, particularly focusing on:

• Microtask queue priority (process.nextTick and Promises)
• I/O operations timing and execution order
• Timer behavior and scheduling
• Event loop phases interaction
• Edge cases and special scenarios

🔍 Key Concepts Demonstrated

1. Microtask Priority

• How process.nextTick and Promises are prioritized
• Microtask execution between different event loop phases

2. I/O Operations

• File system operations timing
• I/O callbacks execution order
• Nested I/O operations behavior

3. Timer Operations

• setTimeout and setInterval behavior
• Timer precision and scheduling
• Interaction between timers and other operations

4. Event Loop Phases

• Complete phase-by-phase execution flow
• Priority order between different types of operations
• Close events and cleanup phase

🚀 Getting Started

1. Install dependencies:
2. Run individual examples:

pnpm install
ts-node priorityTesting/<filename>.ts

📖 Examples Explanation

Microtask Queue (mircrotaskQueue.ts)

Demonstrates how microtasks (process.nextTick and Promises) are executed with priority over other operations in the event loop.

I/O and Timer Interaction (io_timer_check.ts)

Shows how I/O operations interact with timers and their execution order in the event loop.

Comprehensive Comparison (allComparison.ts)

Provides a complete overview of how different types of operations (I/O, timers, microtasks) interact within the event loop.

Edge Cases (wierdTimer_io.ts)

Explores special cases and unexpected behaviors in timer and I/O operation interactions.

🤝 Contributing

Feel free to contribute additional examples or improvements to existing ones. Please ensure any new examples follow the existing pattern and include clear comments explaining the expected behavior.