Tracking issue: HTTP_PROXY/HTTPS_PROXY/NO_PROXY support in Node.js

• Support https/http proxies via HTTP_PROXY/HTTPS_PROXY/NO_PROXY in fetch() (behind NODE_USE_ENV_PROXY)
  • Initial support https://github.com/nodejs/node/pull/57165
  • align with curl: do not tunnel for http proxy https://github.com/nodejs/undici/issues/4083
  • align with curl: support keep-alive https://github.com/nodejs/undici/issues/4086
• Support https/http proxies via HTTP_PROXY/HTTPS_PROXY/NO_PROXY in http(s) builtins (behind NODE_USE_ENV_PROXY)
  • Initial support for http(s).request and agent: https://github.com/nodejs/node/pull/58980
  • Check that it allows other popular user-land agents (for proxy or not) to operate with/without NODE_USE_ENV_PROXY (investigation)
  • Check that it works transparently with popular npm packages that uses http/https.request (investigation)
• Investigate enabling NODE_USE_ENV_PROXY by default
  • In fetch() (less risky since fetch is patched less in the wild)
  • In http(s) builtins (might be too risky, need to investigate)
• Share code between the fetch and the http(s) builtin implementation (e.g. env var parsing & matching)
• Add a CLI flag that allows enabling proxies: https://github.com/nodejs/node/issues/59100
• Bug fixes: https://github.com/nodejs/node/issues/62054

Some nice to haves (depend on whether there are volunteers that want to pick them up):

• Socks 5 proxy support
  • Socks5 proxy support in undici: https://github.com/nodejs/undici/issues/2224
  • Socks5 proxy support in http/https builtins
• HTTP2 support? https://github.com/nodejs/node/issues/57872#issuecomment-3209437143
  • Support it properly in the http2.connect
  • Until then, make sure fetch() doesn't advertise h2 when proxy is enabled?

Old issues: https://github.com/nodejs/node/issues/8381 https://github.com/nodejs/node/issues/15620

Start by choosing one unchecked item, then read the linked Undici or Node.js issue and the existing fetch(), http(s).request, or http2.connect proxy work it references. Define completion against that item's stated behavior and add or update coverage for the selected proxy scenario; this tracking issue does not name specific files or tests.