update redis_db.js

model/db/redis_db.js

@@ -141,10 +141,11 @@ async function readRedis(key) {
     // REDIS_INSTANCE.get(key)
     redis_get(key)
       .then(result => {
-        console.log("redis_get=", result); // Prints "value"
+        // console.log("redis_get=", result); // Prints "value"
         resolve(result);
       }).catch(e => {
         console.log("readRedis key error=", key, e); // Prints "error"
+        resolve(null);
       });
   })
 }
@@ -157,4 +158,5 @@ module.exports = {
   readRedis,
   readAppendRedis,
   writeAppendRedis,
+  formatRedisKey,
 }