request.signal is never fired in dev server

[DanielBaulig]

Reproduction

https://stackblitz.com/edit/remix-run-remix-jkyczz?file=app%2Froutes%2Fstream.tsx

Based on discussion: #8461

The effects of the bug are twofold:

• Actual abort signal behavior cannot be tested and verified using the dev server.
• The dev server might leak resources that should have been freed when the request was cancelled.

Not that the bug only applies to the dev server. Using the express server the request abort signal is fired correctly.

System Info

See Stackblitz

Used Package Manager

npm

Expected Behavior

Dev server should print 'Received Abort!' when the response gets cancelled a second in.

Actual Behavior

Silence.