added default error messages to errorResponse and badRequest

assets/js/src/ajax.js

@@ -60,13 +60,7 @@ define('ajax', ['mailpoet', 'jquery', 'underscore'], function(MailPoet, jQuery,
         ).then(function(data) {
           return data;
         }, function(xhr) {
-          if (!xhr.responseJSON) {
-            return {
-              errors: [{ error: 'undefined', message: "An unknown error occurred." }]
-            };
-          } else {
           return xhr.responseJSON;
-          }
         });
 
         // clear options

lib/API/Endpoint.php

@@ -15,11 +15,20 @@ abstract class Endpoint {
   function errorResponse(
     $errors = array(), $meta = array(), $status = Response::STATUS_NOT_FOUND
   ) {
-
+    if(empty($errors)) {
+      $errors = array(
+        'unknown' => __('An unknown error occurred.')
+      );
+    }
     return new ErrorResponse($errors, $meta, $status);
   }
 
   function badRequest($errors = array(), $meta = array()) {
+    if(empty($errors)) {
+      $errors = array(
+        'bad_request' => __('Invalid request parameters.')
+      );
+    }
     return new ErrorResponse($errors, $meta, Response::STATUS_BAD_REQUEST);
   }
 }

tests/unit/API/SettingsTest.php

@@ -36,6 +36,7 @@ class SettingsTest extends MailPoetTest {
     $router = new Settings();
 
     $response = $router->set(/* missing data */);
+    expect($response->errors[0]['error'])->equals('bad_request');
     expect($response->status)->equals(Response::STATUS_BAD_REQUEST);
 
     $response = $router->set($new_settings);

views/settings.html

@@ -110,7 +110,7 @@
         $('.mailpoet_page_preview').on('click', function() {
           var selection = $(this).siblings('.mailpoet_page_selection');
 
-          if(selection.length > 0) {
+          if (selection.length > 0) {
             $(this).attr('href', $(selection).find('option[value="'+$(selection).val()+'"]').data('preview-url'));
             $(this).attr('target', '_blank');
           } else {