move socket handling to extra file (not GameCommon)

server/GameSockets.js

@@ -0,0 +1,43 @@
+// Map<gameId, Socket[]>
+const SOCKETS = {}
+
+function socketExists(gameId, socket) {
+  if (!(gameId in SOCKETS)) {
+    return false
+  }
+  return SOCKETS[gameId].includes(socket)
+}
+
+function removeSocket(gameId, socket) {
+  if (!(gameId in SOCKETS)) {
+    return
+  }
+  SOCKETS[gameId] = SOCKETS[gameId].filter(s => s !== socket)
+  console.log('removed socket: ', gameId, socket.protocol)
+  console.log('socket count: ', Object.keys(SOCKETS[gameId]).length)
+}
+
+function addSocket(gameId, socket) {
+  if (!(gameId in SOCKETS)) {
+    SOCKETS[gameId] = []
+  }
+  if (!SOCKETS[gameId].includes(socket)) {
+    SOCKETS[gameId].push(socket)
+    console.log('added socket: ', gameId, socket.protocol)
+    console.log('socket count: ', Object.keys(SOCKETS[gameId]).length)
+  }
+}
+
+function getSockets(gameId) {
+  if (!(gameId in SOCKETS)) {
+    return []
+  }
+  return SOCKETS[gameId]
+}
+
+export default {
+  addSocket,
+  removeSocket,
+  socketExists,
+  getSockets,
+}