fix: promise should return val

Author: zzswang

.gitignore

@@ -40,3 +40,4 @@ jspm_packages
 logs/
 certs/
 .vscode/*.sql
+.vscode/settings.json

lib/client/NativeKafkaClient.js

@@ -104,15 +104,15 @@ class NativeKafkaClient extends KafkaClient {
                 debug("consumer ready");
 
                 if (withBackPressure) {
-                    this.consumer.consume((message, done) => {
+                    return this.consumer.consume((message, done) => {
                         super.emit("message", message);
                         done();
-                    }, false, false, this.batchOptions).catch(e => kafkaErrorCallback(e));
+                    }, false, false, this.batchOptions);
                 } else {
-                    this.consumer.consume().catch(e => kafkaErrorCallback(e));
                     this.consumer.on("message", message => {
                         super.emit("message", message);
                     });
+                    return this.consumer.consume();
                 }
             }).catch(e => kafkaErrorCallback(e));
         });