Add support for node-redis v4.0.0 and newer

- Fixes #8420
- v4.0.0 and newer of node-redis will no longer auto-connect, so we need to add that step
- For backwards compatibility, we check for the existence of a "v4" property so we don't try to call `connect` on older versions of the client
- A `legacyMode` flag exists in the new v4.0.0 of node-redis to keep a similar calling style without having to change any code
- This option can be passed via the createClient options, so I've added documentation to indicate that this is required if users would like to use v4.0.0 of node-redis
- Note that the legacyMode flag is **required** to be passed if the calling code isn't going to be changed

docs/caching.md

@@ -149,8 +149,9 @@ Example:
 }
 ```
 
-"options" can be [node_redis specific options](https://github.com/NodeRedis/node_redis#options-object-properties) or [ioredis specific options](https://github.com/luin/ioredis/blob/master/API.md#new-redisport-host-options) depending on what type you're using.
+"options" can be [node_redis specific options](https://github.com/redis/node-redis/blob/master/docs/client-configuration.md) or [ioredis specific options](https://github.com/luin/ioredis/blob/master/API.md#new-redisport-host-options) depending on what type you're using.
 
+If you are using node-redis v4.0.0 or newer, make sure to pass `legacyMode: true` in the "options" for the client to operate correctly.
 
 In case you want to connect to a redis-cluster using IORedis's cluster functionality, you can do that as well by doing the following:
 

src/cache/RedisQueryResultCache.ts

@@ -55,6 +55,9 @@ export class RedisQueryResultCache implements QueryResultCache {
             } else {
                 this.client = this.redis.createClient();
             }
+            if ("v4" in this.client) {
+                await this.client.connect();
+            }
         } else if (this.clientType === "ioredis") {
             if (cacheOptions && cacheOptions.port) {
                 if (cacheOptions.options) {