added property errors for polylint

Author: tlouisse

paper-input.html

@@ -177,15 +177,34 @@
       Polymer.PaperInputBehavior
     ],
 
+    properties: {
+      /*
+       * Errors that are exposed by validatable element.
+       * The error with the highest priority in this list will be shown when validatable is in error state, and no error-message is supplied.
+       */
+      errors: {
+        type: Array,
+        value: function () {
+          return [];
+        }
+      }
+    },
+
     /**
      * Makes sure only error messages with the highest priority are shown.
      * @param {Object} item The error object to be filtered out.
-     * @return {boolean} True if `value` has the highest priority.
+     * @return {boolean} whether the item should be shown based on priority
      */
     _showHighestPrio: function (item) {
       return item.priority < 1;
     },
 
+    /**
+     * Determines whether error with highest priority from errors array needs to be shown.
+     * This error will be visible when property error-message is not supplied and the errors array is not empty.
+     * @param {Array} errors array
+     * @return {boolean} whether error with highest priority from errors array will be shown.
+     */
     _showErrors: function(errors) {
       return !this.errorMessage && errors;
     }