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Promises - All Resources

Section Overview

Microtask Queue, Promise Execution, then/catch, Promise Internals

Deep understanding of Promise implementation, microtask queue, and async/await patterns.

📚 Complete Resource Collection (15 Resources)

Visual Understanding

1. ⭐️🎀 JavaScript Visualized: Promises & Async/Await

Author: Lydia Hallie
Type: Visual Understanding
URL: https://dev.to/lydiahallie/javascript-visualized-promises-async-await-5gke

Focus: Promise lifecycle, microtask queue, async/await internals

Why Essential: Visual understanding of promise execution

2. JavaScript Visualized - Promise Execution

Author: Lydia Hallie
Type: Visual Understanding
URL: https://www.lydiahallie.com/blog/promise-execution

Focus: Promise Object internals, [[PromiseState]], [[PromiseResult]], Promise Capability records

Why Essential: Internal promise object structure

Frontend Masters Course

3. JavaScript: The New Hard Parts - Promises Section

Author: Will Sentance
Type: Frontend Masters Course
URL: https://frontendmasters.com/courses/javascript-new-hard-parts/

Focus: Will Sentance's under-the-hood promise implementation, two-pronged façade functions, microtask queue mechanics

Why Essential: Complete promise understanding from Will Sentance

Deep Technical Understanding

4. Deep Dive into JavaScript Promises

Author: Tech Buildy
Type: Deep Technical Understanding
URL: https://medium.com/@tech.buildy/deep-dive-into-javascript-promises-9f5c7762b11a

Focus: Promise interaction with JavaScript runtime, microtask queue mechanics

Why Essential: Promise runtime interaction details

5. Some questions about Promise in JavaScript

Author: Stack Overflow
Type: Deep Technical Understanding
URL: https://stackoverflow.com/questions/53918221/some-questions-about-promise-in-javascript

Focus: Promise internals creating microtask queue entries, then callback storage

Why Essential: Promise internal mechanics Q&A

6. Microtasks and event loop

Author: JavaScript.info
Type: Deep Technical Understanding
URL: https://tr.javascript.info/microtask-queue

Focus: Promise jobs queue (microtask queue) in V8, asynchronous promise handling

Why Essential: V8 promise implementation details

Official Documentation

7. Using promises - MDN

Author: MDN
Type: Official Documentation
URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_promises

Focus: Promise chaining, error handling, async patterns

Why Essential: Official promise usage guide

Mental Models

8. Just JavaScript - Promises

Author: Dan Abramov
Type: Mental Models
URL: https://justjavascript.com/

Focus: Mental model building for promise understanding

Why Essential: Correct mental models for promises

Advanced Promise Patterns

9. JavaScript Promises: An introduction

Author: Web.dev
Type: Advanced Promise Patterns
URL: https://web.dev/promises/

Focus: Promise states, chaining, error handling, performance

Why Essential: Comprehensive promise introduction

10. Promise Implementation from Scratch

Author: Level Up Coding
Type: Advanced Promise Patterns
URL: https://levelup.gitconnected.com/understand-javascript-promises-by-building-a-promise-from-scratch-84c0fd855720

Focus: Building promises from scratch, understanding internals

Why Essential: Complete understanding through implementation

11. Advanced Promise Patterns

Author: Bit
Type: Advanced Promise Patterns
URL: https://blog.bitsrc.io/advanced-promise-patterns-promise-memoization-3f8f4c5d8d8b

Focus: Promise memoization, advanced async patterns

Why Essential: Advanced promise usage patterns

12. JavaScript Promises Fundamentals Every Engineer Should Know

Author: YouTube
Type: Advanced Promise Patterns
URL: https://www.youtube.com/watch?v=KIovWu7DJO0

Focus: Promise fundamentals, microtask queue, event loop interaction

Why Essential: Video explanation of promise fundamentals

13. 101 Series: Promises #1 - How Promises Work

Author: Xnimorz
Type: Deep Technical Understanding
URL: https://dev.to/xnimorz/101-series-promises-1-how-promises-work-1k1i

Focus: Comprehensive guide to promise mechanics, implementation details, and practical usage patterns

Why Essential: Detailed explanation of how promises work under the hood with practical examples

14. JS Promises #2: How to Get Current Promise Status and Build Your Own Promise Queue

Author: Xnimorz (Nik)
Type: Deep Technical Understanding
URL: https://dev.to/xnimorz/js-promises-2-how-to-get-current-promise-status-and-build-your-own-promise-queue-3lkd

Focus: Promise status inspection, custom promise queue implementation, advanced promise patterns

Why Essential: Learn how to build custom promise management systems and inspect promise states

15. JS Promises #3: Garbage Collection and Memory Leaks

Author: Xnimorz (Nik)
Type: Advanced Promise Patterns
URL: https://dev.to/xnimorz/js-promises-3-garbage-collection-and-memory-leaks-25ol

Focus: Promise memory management, garbage collection with promises, preventing memory leaks

Why Essential: Understanding memory implications of promise usage and avoiding common memory pitfalls

🎯 Learning Path for This Section

Beginner Level

  1. Start with Lydia Hallie's Visual Understanding for promise visualization
  2. Read MDN's Official Documentation for basic promise usage

Intermediate Level

  1. Study Will Sentance's Frontend Masters Course for complete understanding
  2. Read Web.dev's comprehensive introduction

Advanced Level

  1. Dive into Deep Technical Understanding resources for internals
  2. Study V8 promise implementation details

Expert Level

  1. Build Promise Implementation from Scratch for complete understanding
  2. Master Advanced Promise Patterns and optimization techniques

💡 Key Concepts Covered

  • Promise States: Pending, fulfilled, rejected
  • Microtask Queue: High-priority async execution
  • Promise Chaining: Sequential async operations
  • Error Handling: Catch and finally mechanisms
  • async/await: Syntactic sugar over promises
  • Promise Internals: [[PromiseState]], [[PromiseResult]]
  • Performance: Promise optimization and best practices

Study Tip

Focus on understanding promises as two-pronged façade functions that trigger both immediate synchronous code and future asynchronous code via the microtask queue. Practice tracing promise execution through the event loop.