feat: implement the Redis adapter

We had to make a few changes to the redis module (in the vendor/
directory), in order to implement the feature. We will remove it once
the changes are merged upstream.

See also: denodrivers/redis#335

This implementation is compatible with the Node.js one (same format for
the Redis channels and the packets).

See also: https://github.com/socketio/socket.io-redis-adapter

.github/workflows/ci.yml

@@ -15,6 +15,17 @@ jobs:
         deno-version:
           - 1.25.2
 
+    services:
+      redis:
+        image: redis
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 6379:6379
+
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2

README.md

@@ -17,6 +17,8 @@ Table of content:
   - [`editHandshakeHeaders`](#edithandshakeheaders)
   - [`editResponseHeaders`](#editresponseheaders)
 - [Logs](#logs)
+- [Adapters](#adapters)
+  - [Redis adapter](#redis-adapter)
 
 ## Usage
 
@@ -231,6 +233,41 @@ await log.setup({
 });
 ```
 
+## Adapters
+
+Custom adapters can be used to broadcast packets between several Socket.IO
+servers.
+
+### Redis adapter
+
+Documentation: https://socket.io/docs/v4/redis-adapter/
+
+```js
+import { serve } from "https://deno.land/std/http/server.ts";
+import {
+  createRedisAdapter,
+  createRedisClient,
+  Server,
+} from "https://deno.land/x/socket_io/mod.ts";
+
+const [pubClient, subClient] = await Promise.all([
+  createRedisClient({
+    hostname: "localhost",
+  }),
+  createRedisClient({
+    hostname: "localhost",
+  }),
+]);
+
+const io = new Server({
+  adapter: createRedisAdapter(pubClient, subClient),
+});
+
+await serve(io.handler(), {
+  port: 3000,
+});
+```
+
 ## License
 
 [ISC](/LICENSE)

docker-compose.yml

@@ -0,0 +1,6 @@
+version: "3.0"
+services:
+  redis:
+    image: redis:5
+    ports:
+      - "6379:6379"

mod.ts

@@ -1 +1,47 @@
-export { Server, type ServerOptions } from "./packages/socket.io/mod.ts";
+export {
+  Adapter,
+  type BroadcastOptions,
+  type Namespace,
+  Server,
+  type ServerOptions,
+  type Socket,
+} from "./packages/socket.io/mod.ts";
+
+/**
+ * The Redis adapter, to broadcast packets between several Socket.IO servers
+ *
+ * Documentation: https://socket.io/docs/v4/redis-adapter/
+ *
+ * Usage:
+ *
+ * ```
+ * import { serve } from "https://deno.land/std/http/server.ts";
+ * import { Server, createRedisAdapter, createRedisClient } from "https://deno.land/x/socket_io/mod.ts";
+ *
+ * const [pubClient, subClient] = await Promise.all([
+ *   createRedisClient({
+ *     hostname: "localhost",
+ *   }),
+ *   createRedisClient({
+ *     hostname: "localhost",
+ *   })
+ * ]);
+ *
+ * const io = new Server({
+ *     adapter: createRedisAdapter(pubClient, subClient)
+ * });
+ *
+ * await serve(io.handler(), {
+ *     port: 3000
+ * });
+ * ```
+ */
+export {
+  createAdapter as createRedisAdapter,
+  type RedisAdapterOptions,
+} from "./packages/socket.io-redis-adapter/mod.ts";
+
+/**
+ * Temporary export to provide a workaround for https://github.com/denodrivers/redis/issues/335
+ */
+export { connect as createRedisClient } from "./vendor/deno.land/x/redis@v0.27.1/mod.ts";