shadow-cljs

orestis 2025-11-14T10:19:14.031019Z

Using :target :esm in dev mode, it seems like the network requests to get all the JS seem to take quite a long time - I see 15s roughly for DOMContentLoaded... The network tab is quite busy with requests set to (pending)

orestis 2025-11-18T10:02:46.048869Z

I couldn’t find any reference to ESM not being subject to the http connection limit. Perhaps for faster dev we’d need http2 but it’s a pain

orestis 2025-11-18T11:02:10.009289Z

I tried with https/h2 and it seems the loading time is comparable. I switched shadow-cljs and our own server to ssl with a mkcert certificate. Everything worked fine but again the behaviour was the same - a ton of waterfall-like requests in the backlog.

orestis 2025-11-14T10:33:41.270999Z

Presumably this is because of the old 6-connections-per-server limit... But we were always using :loader-mode :eval which was still downloading invididual files IIRC?

thheller 2025-11-15T17:12:00.073929Z

esm doesn't have the 6 connection limit I think? but :loader-mode does not exist in :esm, it always uses the built-in browser import thing

thheller 2025-11-19T18:52:54.505129Z

How many files are we talking? I never much tested this with :esm and just assumed that browser just had addressed these issues 😛

thheller 2025-11-19T18:53:08.595659Z

but I guess yeah the server still matters

thheller 2025-11-19T18:53:23.640659Z

I can see about making the :eval mode available for :esm