Slowserver is a simple web app with an intentionally slow responding endpoint and a websocket echo and websocket pinger endpoint.
This can be useful for testing HTTP clients and proxies.
Also included is wsocat, a command line websocket client.
Use go install to install slowserver and wsocat.
go install github.com/jrwren/slowserver/...
In one shell run the server:
slowserver
Then run wsocat to connect to it:
wsocat ws://localhost:8080/ws-pinger