remove step 3: refactor

lib/cartodb/backends/template_maps.js

@@ -266,19 +266,17 @@ TemplateMaps.prototype.addTemplate = function(owner, template, callback) {
 // @param callback function(err)
 //
 TemplateMaps.prototype.delTemplate = function(owner, tpl_id, callback) {
-    var self = this;
+    this._redisCmd('HDEL', [ this.key_usr_tpl({ owner:owner }), tpl_id ], (err, deleted) => {
+        if (err) {
+            return callback(err);
+        }
 
-    self._redisCmd('HDEL', [ self.key_usr_tpl({ owner:owner }), tpl_id ], (err, deleted) => {
-        assert.ifError(err);
         if (!deleted) {
-            throw new Error("Template '" + tpl_id + "' of user '" + owner + "' does not exist");
+            return callback(new Error(`Template '${tpl_id}' of user '${owner}' does not exist`));
         }
 
-        if (!err) {
-            self.emit('delete', owner, tpl_id);
-        }
-
-        return callback(err);
+        this.emit('delete', owner, tpl_id);
+        return callback();
     });
 };