Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/quickedit/js/models/BaseModel.js

@@ -0,0 +1,52 @@
+/**
+ * @file
+ * A Backbone Model subclass that enforces validation when calling set().
+ */
+
+(function (Backbone) {
+
+  "use strict";
+
+  Drupal.quickedit.BaseModel = Backbone.Model.extend(/** @lends Drupal.quickedit.BaseModel# */{
+
+    /**
+     * @constructs
+     *
+     * @augments Backbone.Model
+     *
+     * @param {object} options
+     *
+     * @return {Drupal.quickedit.BaseModel}
+     */
+    initialize: function (options) {
+      this.__initialized = true;
+      return Backbone.Model.prototype.initialize.call(this, options);
+    },
+
+    /**
+     *
+     * @param {object|string} key
+     * @param {*} val
+     * @param {object} [options]
+     *
+     * @return {*}
+     */
+    set: function (key, val, options) {
+      if (this.__initialized) {
+        // Deal with both the "key", value and {key:value}-style arguments.
+        if (typeof key === 'object') {
+          key.validate = true;
+        }
+        else {
+          if (!options) {
+            options = {};
+          }
+          options.validate = true;
+        }
+      }
+      return Backbone.Model.prototype.set.call(this, key, val, options);
+    }
+
+  });
+
+}(Backbone));