Koa v4 Tracker

[jonathanong]

New tracker for v4 as I plan to launch v3 soon:

Breaking Changes:

• adjust naming to WHATWG standards https://nodejs.org/api/url.html#url_url_strings_and_url_objects
• rename raw http requests? koa 3.0 roadmap #1114 (comment)

Refactor & Rewrite:

• Rewrite in TypeScript Distribute TypeScript types with koa package #1607
  • Need to rewrite all submodules in TypeScript first!
• Update node.js modules (e.g. node:assert, etc.)

Platform Support:

• Deno support
• Bun support
• HTTP2 support [fix] Request.secure returns false for HTTP2 connections after recieving RST_STREAM #1736

Features:

• Improved stream support [feat] Improved stream handling #1864 [bug] TCP memory leak caused by aborted client connections when streaming data with node-fetch #1834
• Improved forwarded headers support [fix] ctx.request.origin ignores proxy flag (X-Forwarded-Proto) #1746 request.ip via x-forwarded-for should strip out ports #827 integrate proxy-addr #281
• [feat] Support trailer headers #1707

Improved Documentation:

• example of how to use expect-continue
• How to sent Content-Length on a HEAD response #1827