fix: ensure CSR works with the ioredis package

Author: darrachequesne

lib/adapter.ts

@@ -9,7 +9,7 @@ import type {
 } from "socket.io-adapter";
 import { decode, encode } from "@msgpack/msgpack";
 import debugModule from "debug";
-import { hasBinary, XADD, XREAD } from "./util";
+import { hasBinary, GETDEL, SET, XADD, XRANGE, XREAD } from "./util";
 
 const debug = debugModule("socket.io-redis-streams-adapter");
 
@@ -235,9 +235,12 @@ class RedisStreamsAdapter extends ClusterAdapterWithHeartbeat {
     const sessionKey = this.#opts.sessionKeyPrefix + session.pid;
     const encodedSession = Buffer.from(encode(session)).toString("base64");
 
-    this.#redisClient.set(sessionKey, encodedSession, {
-      PX: this.nsp.server.opts.connectionStateRecovery.maxDisconnectionDuration,
-    });
+    SET(
+      this.#redisClient,
+      sessionKey,
+      encodedSession,
+      this.nsp.server.opts.connectionStateRecovery.maxDisconnectionDuration
+    );
   }
 
   override async restoreSession(
@@ -253,12 +256,8 @@ class RedisStreamsAdapter extends ClusterAdapterWithHeartbeat {
     const sessionKey = this.#opts.sessionKeyPrefix + pid;
 
     const results = await Promise.all([
-      this.#redisClient
-        .multi()
-        .get(sessionKey)
-        .del(sessionKey) // GETDEL was added in Redis version 6.2
-        .exec(),
-      this.#redisClient.xRange(this.#opts.streamName, offset, offset),
+      GETDEL(this.#redisClient, sessionKey),
+      XRANGE(this.#redisClient, this.#opts.streamName, offset, offset),
     ]);
 
     const rawSession = results[0][0];
@@ -277,13 +276,11 @@ class RedisStreamsAdapter extends ClusterAdapterWithHeartbeat {
     // FIXME we need to add an arbitrary limit here, because if entries are added faster than what we can consume, then
     // we will loop endlessly. But if we stop before reaching the end of the stream, we might lose messages.
     for (let i = 0; i < RESTORE_SESSION_MAX_XRANGE_CALLS; i++) {
-      const entries = await this.#redisClient.xRange(
+      const entries = await XRANGE(
+        this.#redisClient,
         this.#opts.streamName,
         RedisStreamsAdapter.nextOffset(offset),
-        "+",
-        {
-          COUNT: this.#opts.readCount,
-        }
+        "+"
       );
 
       if (entries.length === 0) {

lib/util.ts

@@ -47,6 +47,23 @@ function isRedisV4Client(redisClient: any) {
   return typeof redisClient.sSubscribe === "function";
 }
 
+/**
+ * Map the output of the XREAD/XRANGE command with the ioredis package to the format of the redis package
+ * @param result
+ */
+function mapResult(result) {
+  const id = result[0];
+  const inlineValues = result[1];
+  const message = {};
+  for (let i = 0; i < inlineValues.length; i += 2) {
+    message[inlineValues[i]] = inlineValues[i + 1];
+  }
+  return {
+    id,
+    message,
+  };
+}
+
 /**
  * @see https://redis.io/commands/xread/
  */
@@ -81,18 +98,7 @@ export function XREAD(
         }
         return [
           {
-            messages: results[0][1].map((result) => {
-              const id = result[0];
-              const inlineValues = result[1];
-              const message = {};
-              for (let i = 0; i < inlineValues.length; i += 2) {
-                message[inlineValues[i]] = inlineValues[i + 1];
-              }
-              return {
-                id,
-                message,
-              };
-            }),
+            messages: results[0][1].map(mapResult),
           },
         ];
       });
@@ -125,3 +131,58 @@ export function XADD(
     return redisClient.xadd.call(redisClient, args);
   }
 }
+
+/**
+ * @see https://redis.io/commands/xrange/
+ */
+export function XRANGE(
+  redisClient: any,
+  streamName: string,
+  start: string,
+  end: string
+) {
+  if (isRedisV4Client(redisClient)) {
+    return redisClient.xRange(streamName, start, end);
+  } else {
+    return redisClient.xrange(streamName, start, end).then((res) => {
+      return res.map(mapResult);
+    });
+  }
+}
+
+/**
+ * @see https://redis.io/commands/set/
+ */
+export function SET(
+  redisClient: any,
+  key: string,
+  value: string,
+  expiryInSeconds: number
+) {
+  if (isRedisV4Client(redisClient)) {
+    return redisClient.set(key, value, {
+      PX: expiryInSeconds,
+    });
+  } else {
+    return redisClient.set(key, value, "PX", expiryInSeconds);
+  }
+}
+
+/**
+ * @see https://redis.io/commands/getdel/
+ */
+export function GETDEL(redisClient: any, key: string) {
+  if (isRedisV4Client(redisClient)) {
+    // note: GETDEL was added in Redis version 6.2
+    return redisClient.multi().get(key).del(key).exec();
+  } else {
+    return redisClient
+      .multi()
+      .get(key)
+      .del(key)
+      .exec()
+      .then((res) => {
+        return [res[0][1]];
+      });
+  }
+}