From 2c7f4516abe3990a3d5eda0fdc3493f40f44787c Mon Sep 17 00:00:00 2001
From: Max Goodhart <c@chromakode.com>
Date: Mon, 6 Jul 2020 21:07:59 -0700
Subject: [PATCH] Periodically send ping to WebSocket

This may help keep the WebSocket alive in some firewall situations.
---
 src/node/server.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/node/server.js b/src/node/server.js
index 65772ff..20265e9 100644
--- a/src/node/server.js
+++ b/src/node/server.js
@@ -57,8 +57,13 @@ function initApp({
 
         ws.binaryType = 'arraybuffer'
 
+        const pingInterval = setInterval(() => {
+          ws.ping()
+        }, 20 * 1000)
+
         ws.on('close', () => {
           sockets.delete(ws)
+          clearInterval(pingInterval)
         })
 
         ws.on('message', (rawData) => {