MM-18827 - Can not use api/v4/websocket with trailing slash (#12931)

api4/websocket.go

@@ -12,7 +12,8 @@ import (
 )
 
 func (api *API) InitWebSocket() {
-	api.BaseRoutes.ApiRoot.Handle("/websocket", api.ApiHandlerTrustRequester(connectWebSocket)).Methods("GET")
+	// Optionally supports a trailing slash
+	api.BaseRoutes.ApiRoot.Handle("/{websocket:websocket(?:\\/)?}", api.ApiHandlerTrustRequester(connectWebSocket)).Methods("GET")
 }
 
 func connectWebSocket(c *Context, w http.ResponseWriter, r *http.Request) {