fix(connection): throw error when Upstash host is provided (#1098) fixes

 #1087

src/classes/redis-connection.ts

@@ -20,6 +20,8 @@ const deprecationMessage = [
   'On the next versions having this settings will throw an exception',
 ].join(' ');
 
+const upstashMessage = 'BullMQ: Upstash is not compatible with BullMQ.';
+
 export class RedisConnection extends EventEmitter {
   static minimumVersion = '5.0.0';
   protected _client: RedisClient;
@@ -48,14 +50,16 @@ export class RedisConnection extends EventEmitter {
         maxRetriesPerRequest: null,
         enableReadyCheck: false,
       };
+      this.checkUpstashHost(this.opts.host);
     } else {
       this._client = <RedisClient>opts;
-      let options = this._client.options;
+      let options = <IORedis.RedisOptions>this._client.options;
       if ((<IORedis.ClusterOptions>options)?.redisOptions) {
         options = (<IORedis.ClusterOptions>options).redisOptions;
       }
 
       this.checkOptions(deprecationMessage, options);
+      this.checkUpstashHost(options.host);
     }
 
     this.handleClientError = (err: Error): void => {
@@ -72,6 +76,12 @@ export class RedisConnection extends EventEmitter {
     }
   }
 
+  private checkUpstashHost(host: string) {
+    if (host.endsWith('upstash.io')) {
+      throw new Error(upstashMessage);
+    }
+  }
+
   /**
    * Waits for a redis client to be ready.
    * @param redis - client

tests/test_connection.ts

@@ -42,6 +42,20 @@ describe('connection', () => {
     checkOptions(await queue.client);
   });
 
+  describe('when host belongs to Upstash', async () => {
+    it('throws an error', async () => {
+      const opts = {
+        connection: {
+          host: 'https://upstash.io',
+        },
+      };
+
+      expect(() => new QueueBase(queueName, opts)).to.throw(
+        'BullMQ: Upstash is not compatible with BullMQ.',
+      );
+    });
+  });
+
   it('should recover from a connection loss', async () => {
     let processor;