Fixed issue of case where output is empty

backend/subscriptions.js

@@ -254,13 +254,13 @@ exports.getVideosForSub = async (sub, user_uid = null) => {
             }
 
             logger.verbose('Subscription: finished check for ' + sub.name);
-            const processed_output = utils.parseOutputJSON(output, err);
+            const parsed_output = utils.parseOutputJSON(output, err);
-            if (!processed_output) {
+            if (!parsed_output) {
                 logger.error('Subscription check failed!');
                 resolve(null);
                 return;
             }
-            const files_to_download = await handleOutputJSON(processed_output, sub, user_uid);
+            const files_to_download = await handleOutputJSON(parsed_output, sub, user_uid);
             resolve(files_to_download);
             return;
         });

backend/utils.js

@@ -545,7 +545,10 @@ exports.parseOutputJSON = (output, err) => {
             logger.error(e);
             return null;
         }
-    }   else {
+    } else if (output.length === 0 || (output.length === 1 && output[0].length === 0)) {
+        // output is '' or ['']
+        return [];
+    } else {
         for (const output_item of output) {
             // we have to do this because sometimes there will be leading characters before the actual json
             const start_idx = output_item.indexOf('{"');