Parcel: Failed to construct 'WebSocket': The URL 'ws://:61948/' is invalid

[Slapbox]

For whatever reason the hot-loader is not recognizing my hostname. I'm also not able to populate HMR_HOSTNAME, although I have no problem populating other environmental variables using cross-env

🌍 Your Environment

| Software | Version(s) |
| ---------------- | ---------- |
| Parcel | 1.6.1
| Node | 8.9.1
| npm/Yarn | 1.3.2 (yarn)
| Operating System | Windows 7 x64

[DeMoorJasper]

@jbreckmckye could u possibly provide a test repository? I'll try find some time to look into it as it seems to be quite an important bug to fix.

[jbreckmckye]

Thanks for fixing this so quickly!

[ZachSaucier]

I'm still getting this error on version 1.9.2, having to use the --no-hmr flag to avoid it.

[felipemullen]

I'm seeing this issue as well working with an Electron app. It started the moment I added jquery to an html file:

<script src="../lib/js/jquery-3.2.1.slim.min.js"></script>

it's a very simple page, just login with vanilla js and bootstrap. The issue goes away when adding the --no-hmr flag as mentioned by @ZachSaucier

[dz-s]

@devongovett also getting this error on version 1.9.4.
@ZachSaucier the same resolution works.

[j0hnm4r5]

Kind of the same issue here, on ^1.9.7, but weirder.

Basic Websocket connection from client to a node instance running with concurrently. It started off giving the same Failed to construct 'WebSocket' error, then I added the --no-hmr flag and reran it. Without HMR it ran fine.

But then I re-enabled HMR, and it _continued_ to run fine.

[michapietsch]

I came here because of the WebSocket error message. The original issue (first post: populate HMR_HOSTNAME) does not affect me.

But I noticed the error in a quick static demo that I directly opened in the browser. The error went away when I accessed the demo through a server.

Maybe that's it for some of you, too. 🤷‍♂️