Now we know

gen.ts

@@ -1,20 +0,0 @@
-const ALFNUM = "0123456789";
-const SECRET_LENGTH = 8;
-
-function randomInt(low: number, high: number) {
-  return Math.floor(Math.random() * (high - low + 1) + low);
-}
-
-export function randomId() {
-  const arr = new Int32Array(1);
-  crypto.getRandomValues(arr);
-  return Math.abs(arr[0]);
-}
-
-export function randomSecret() {
-  let out = "";
-  for (let i = 0; i < SECRET_LENGTH; i++) {
-    out += ALFNUM[randomInt(0, ALFNUM.length - 1)];
-  }
-  return out;
-}

readme.md

@@ -4,7 +4,9 @@
 
 # Signalling Server
 
-The signaling server is written in TypeScript to run on Deno. It can run in the
+Requires Deno >= 1.16.1
+
+The signaling server is written in TypeScript to run on Deno (1.16.1). It can run in the
 cloud via Deno deploy.
 
     PORT=8888 deno run --allow-env --allow-net server.ts

server.ts

@@ -21,32 +21,52 @@ const lobbies = new Set<Lobby>();
 const clients = new Set<Client>();
 
 console.log("Listening on port", PORT);
-for await (const conn of Deno.listen({ port: PORT })) {
+const listener = Deno.listen({ port: PORT });
+for await (const conn of listener) {
+  console.debug("Connection received:", conn);
   (async () => {
-    for await (const { respondWith, request } of Deno.serveHttp(conn)) {
-      const { socket, response } = Deno.upgradeWebSocket(request);
-      const client: Client = { socket };
-      socket.onmessage = (ev) => {
-        console.log("Client Message Received", ev);
-      };
-      socket.onopen = (ev) => {
-        console.log("New Client:", ev);
-        clients.add(client);
-        socket.send("lobbies_start");
-        lobbies.forEach(({ name, clients }) => {
-          socket.send(JSON.stringify({ name, numClients: clients.length }));
-        });
-        socket.send("lobbies_end");
-      };
-      socket.onclose = (ev) => {
-        console.log("Client Socket Close:", ev);
-        clients.delete(client);
-      };
-      socket.onerror = (ev) => {
-        console.log("Client Socket Error:", ev);
-        clients.delete(client);
-      };
-      respondWith(response);
+    const server = Deno.serveHttp(conn);
+    for await (const { respondWith, request } of server) {
+      console.debug("HTTP Request Received", request);
+      try {
+        const { socket, response } = Deno.upgradeWebSocket(request);
+        const client: Client = { socket };
+        socket.onmessage = (ev) => {
+          console.log("Client Message Received", ev);
+        };
+        socket.onopen = (ev) => {
+          console.log("New Client:", ev);
+          if (!clients.has(client)) clients.add(client);
+          socket.send("lobbies_start");
+          lobbies.forEach(({ name, clients }) => {
+            socket.send(JSON.stringify({ name, numClients: clients.length }));
+          });
+          socket.send("lobbies_end");
+        };
+        socket.onclose = (ev) => {
+          console.log("Client Socket Close:", ev);
+          if (clients.has(client)) clients.delete(client);
+        };
+        socket.onerror = (ev) => {
+          console.log("Client Socket Error:", ev);
+          if (clients.has(client)) clients.delete(client);
+        };
+        respondWith(response);
+      } catch (e) {
+        let body = "400 Bad Request";
+        if (e instanceof TypeError) {
+          body += " - Expected to be able to upgrade to WebSocket connection";
+          console.log("Could not add client:", e);
+        } else {
+          console.log("Could not add client for unhandled reason:", e);
+        }
+        respondWith(
+          new Response(body, {
+            status: 400,
+            headers: { "content-type": "text/html" },
+          }),
+        );
+      }
     }
   })();
 }

types.ts

@@ -1,9 +0,0 @@
-export interface Client {
-  socket: WebSocket;
-}
-
-export interface Lobby {
-  name: string;
-  secret: string;
-  clients: Client[];
-}