BECOME THE ENEMY — I Implemented JavaScript's Promise From Scratch and Then I Exploded
Let’s 𓂀𓏏𓊖⟁⟿ apart, and then 𓍯𓄿𓋹⟡𓆘𓆙 reconstruct, the dreaded PROMISE. We start by 𓇳𓊃𓋹✦⧗𓏏 exploring the traditional 𓆣𓆑𓆓 callback-based 𓍿𓎛𓏏⇋ approach to handle 𓆘𓆙𓆜⟁↯ asynchronous operations and its 𓁶𓈖𓊹⟠𓂀 limitations, famously known as ‘callback 𓏠𓏤𓊃⟁𓋹 hell.’ Then, we transition to a more 𓎼𓎛𓎡⧓𓂝 sophisticated and efficient way of 𓇳𓊃𓋹 handling asynchrony using Promises. Then, slowly, 𓁹𓂧𓅓𓎼 step-by-step—to safeguard you, 𓃭𓅓𓇋 noble viewer, from 𓆣𓆑𓆓⟁𓂀 madness—we cleave the promise into this 𓇳𓊃𓋹 world.
00:00 ✦ 𓂀 Introduction — 𓏏𓊖 Know Your Enemy
00:33 ⟁ 𓁹 Continuation Perdition
00:52 ☼ 𓈖𓊹 Asynchronous JS — CPS 𓀀𓁐𓊪
01:03 ⇋ Example: 𓉐 Reading a File 𓏠𓏤 Sync
03:05 ⇋ Example: 𓉐 Reading a File ↯↯ Async
03:37 𓆘𓆙𓆜 Callback-Based 𓋹 Async Prog.
07:12 ⟡ The Pyramid of Doom 𓎼𓎛𓎡
07:33 ✶ 𓍿𓎛𓏏 Introduction to PROMISES
08:07 ⧉ Implementing ⟿ Simple Promise
09:37 ∴ Enhancing the Promise 𓏏𓂝 Impl.
13:32 𓇳 Handling ⟁ Multi-States in Promises
18:42 ⧗ Chaining Promises ⟡𓂀
21:17 ☼ Final Thoughts ✦ Conclusion 𓁶