What's up TC39
summary
An overview of TC39’s proposal pipeline: the committee has 30+ ECMAScript proposals and uses a four‑stage approval process where Stage 4 requires two major browser implementations plus passing tests. ES2019 finalized features like optional catch binding, Unicode regex fixes and object rest/spread; Stage 3 items include dynamic import(), Array.prototype.flat/flatMap, private class fields and BigInt (42n). Proposals are brought to users via polyfills (e.g., Babel) or engine implementations, and practical compatibility concerns (e.g., globalThis once broke Flickr) can block otherwise attractive changes.
AI-written summary · about
chapters (20)
- 0:00TC39 intro
- 1:14TC39 and JavaScript
- 3:20ECMAScript history
- 6:12TC39 proposal process
- 11:30Standards caution
- 12:54WHATWG role
- 13:15ES2018 features
- 14:39ES2019 stage 4
- 16:43Stage 3 features
- 20:38Dynamic imports
- 21:43New number types
- 23:28Private class fields
- 26:17String methods
- 28:03Module metadata
- 29:30FlatMap evolution
- 32:45Object/Set methods
- 34:09Less likely proposals
- 36:57Optional chaining
- 39:25Tracking proposals
- 42:14Demo & Q&A
