HTML streaming not working with Remix app

[tom-sherman]

Describe the bug

When I run this locally, page is rendered as HTML with the suspense boundary as "Loading..." then the promise resolves on the server and is streamed to the client, and the "Loading..." changes to "Hello World".

On stackblitz though, no data is sent until the entire response is done (and so you see no "Loading..." state)

Link to the blitz that caused the error

https://stackblitz.com/edit/remix-starter-updated-t1fani?file=app%2Froutes%2Findex.tsx,app%2Fentry.server.tsx

Steps to reproduce

1. Open the linked blits
2. Load the index route

Expected behavior

See a Loading... message, and then this changes to "Data: Hello World"

Parity with Local

• I have run the project in my local machine and I could not reproduce the issue.

Screenshots

No response

Platform

Browser name  = Chrome
Full version  = 110.0.0.0
Major version = 110
navigator.appName = Netscape
navigator.userAgent = Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36
performance.memory = {
  "totalJSHeapSize": 83867546,
  "usedJSHeapSize": 82016534,
  "jsHeapSizeLimit": 4294705152
}
Hash = 927bd077ab89da68c6338c4363cc22e79cccb4ef

Additional context

No response

[jrvidal]

👋 Thanks for the report. You're correct, the preview window does not properly stream the response back. This is something we haven't got around implementing.

We're tracking this internally now (thanks!).

[tom-sherman]

@jrvidal I also couldn't get streaming to work when I opened the preview window in a new tab btw

[jrvidal]

Yes, that is expected 👍 It's an issue with our networking stack.

[Rich-Harris]

Chiming in with sveltejs/learn.svelte.dev#352, so that the issues are linked on GitHub! This is currently blocking us from documenting streaming behaviour on learn.svelte.dev, unfortunately

[Nemikolh]

Hey everyone! We have added initial support for HTTP streaming! 🎉

@tom-sherman, I have tested your example and we can now see Loading.. before Data: Hello World!.

@Rich-Harris, I've tested your PR and it also works!

I'll be on the lookout for performance regressions, so if you notice anything please let me know! 😃