manage JSON parse and stringify sinc errors

lib/cartodb/backends/template_maps.js

@@ -297,7 +297,6 @@ TemplateMaps.prototype.delTemplate = function(owner, tpl_id, callback) {
 // @param callback function(err)
 //
 TemplateMaps.prototype.updTemplate = function(owner, tpl_id, template, callback) {
-
     template = templateDefaults(template);
 
     var invalidError = this._checkInvalidTemplate(template);
@@ -320,7 +319,14 @@ TemplateMaps.prototype.updTemplate = function(owner, tpl_id, template, callback)
             return callback(new Error(`Template '${tpl_id}' of user '${owner}' does not exist`));
         }
 
-        this._redisCmd('HSET', [userTemplatesKey, template.name, JSON.stringify(template)], (err, didSetNewField) => {
+        let templateString;
+        try {
+            templateString = JSON.stringify(template)
+        } catch (error) {
+            return callback(error);
+        }
+
+        this._redisCmd('HSET', [userTemplatesKey, template.name, templateString], (err, didSetNewField) => {
             if (err) {
                 return callback(err);
             }
@@ -329,7 +335,14 @@ TemplateMaps.prototype.updTemplate = function(owner, tpl_id, template, callback)
                 debug('New template created on update operation');
             }
 
-            if (this.fingerPrint(JSON.parse(beforeUpdateTemplate)) !== this.fingerPrint(template)) {
+            let beforeUpdateTemplateObject;
+            try {
+                beforeUpdateTemplateObject = JSON.parse(beforeUpdateTemplate)
+            } catch (error) {
+                return callback(error);
+            }
+
+            if (this.fingerPrint(beforeUpdateTemplateObject) !== this.fingerPrint(template)) {
                 this.emit('update', owner, template.name, template);
             }