diff -u b/core/modules/field/field.api.php b/core/modules/field/field.api.php
--- b/core/modules/field/field.api.php
+++ b/core/modules/field/field.api.php
@@ -803,9 +803,9 @@
  * of the hook involves reading from the database, it is highly recommended to
  * statically cache the information.
  *
- * @param $widget_properties
+ * @param array $widget_properties
  *   The instance's widget properties.
- * @param $context
+ * @param array $context
  *   An associative array containing:
  *   - entity_type: The entity type; e.g., 'node' or 'user'.
  *   - bundle: The bundle: e.g., 'page' or 'article'.
@@ -814,7 +814,7 @@
  *
  * @see hook_field_widget_properties_ENTITY_TYPE_alter()
  */
-function hook_field_widget_properties_alter(&$widget_properties, $context) {
+function hook_field_widget_properties_alter(array &$widget_properties, array $context) {
   // Change a widget's type according to the time of day.
   $field = $context['field'];
   if ($context['entity_type'] == 'node' && $field['field_name'] == 'field_foo') {
@@ -2202,9 +2202,9 @@
  * of the hook involves reading from the database, it is highly recommended to
  * statically cache the information.
  *
- * @param $widget_properties
+ * @param array $widget_properties
  *   The instance's widget properties.
- * @param $context
+ * @param array $context
  *   An associative array containing:
  *   - entity_type: The entity type; e.g., 'node' or 'user'.
  *   - bundle: The bundle: e.g., 'page' or 'article'.
@@ -2213,7 +2213,7 @@
  *
  * @see hook_field_widget_properties_alter()
  */
-function hook_field_widget_properties_ENTITY_TYPE_alter(&$widget_properties, $context) {
+function hook_field_widget_properties_ENTITY_TYPE_alter(array &$widget_properties, array $context) {
   // Change a widget's type according to the time of day.
   $field = $context['field'];
   if ($field['field_name'] == 'field_foo') {
diff -u b/core/modules/field/field.attach.inc b/core/modules/field/field.attach.inc
--- b/core/modules/field/field.attach.inc
+++ b/core/modules/field/field.attach.inc
@@ -126,21 +126,21 @@
  *   A parameter for the invoked method. Defaults to NULL.
  * @param array $options
  *   An associative array of additional options, with the following keys:
- *    - field_name: The name of the field whose operation should be invoked. By
- *    default, the operation is invoked on all the fields in the entity's
- *    bundle. NOTE: This option is not compatible with the 'deleted' option;
- *    the 'field_id' option should be used instead.
- *    - field_id: The id of the field whose operation should be invoked. By
- *    default, the operation is invoked on all the fields in the entity's'
- *    bundles.
- *    - deleted: If TRUE, the function will operate on deleted fields as well
- *    as non-deleted fields. If unset or FALSE, only non-deleted fields are
- *    operated on.
- *    - langcode: A language code or an array of language codes keyed by field
- *    name. It will be used to narrow down to a single value the available
- *    languages to act on.
+ *   - field_name: The name of the field whose operation should be invoked. By
+ *     default, the operation is invoked on all the fields in the entity's
+ *     bundle. NOTE: This option is not compatible with the 'deleted' option;
+ *     the 'field_id' option should be used instead.
+ *   - field_id: The id of the field whose operation should be invoked. By
+ *     default, the operation is invoked on all the fields in the entity's'
+ *     bundles.
+ *   - deleted: If TRUE, the function will operate on deleted fields as well
+ *     as non-deleted fields. If unset or FALSE, only non-deleted fields are
+ *     operated on.
+ *   - langcode: A language code or an array of language codes keyed by field
+ *     name. It will be used to narrow down to a single value the available
+ *     languages to act on.
  */
-function field_invoke_method($method, \Closure $target_closure, EntityInterface $entity, &$a = NULL, &$b = NULL, $options = array()) {
+function field_invoke_method($method, \Closure $target_closure, EntityInterface $entity, &$a = NULL, &$b = NULL, array $options = array()) {
   // Merge default options.
   $default_options = array(
     'deleted' => FALSE,
diff -u b/core/modules/field/lib/Drupal/field/FieldInstance.php b/core/modules/field/lib/Drupal/field/FieldInstance.php
--- b/core/modules/field/lib/Drupal/field/FieldInstance.php
+++ b/core/modules/field/lib/Drupal/field/FieldInstance.php
@@ -19,7 +19,13 @@
    */
   protected $widget;
 
-  public function __construct($definition) {
+  /**
+   * Constructs a FieldInstance object.
+   *
+   * @param array $definition
+   *   The instance definition array, as read from configuration storage.
+   */
+  public function __construct(array $definition) {
     $this->definition = $definition;
   }
 
diff -u b/core/modules/field/lib/Drupal/field/Plugin/Type/LegacyDiscoveryDecorator.php b/core/modules/field/lib/Drupal/field/Plugin/Type/LegacyDiscoveryDecorator.php
--- b/core/modules/field/lib/Drupal/field/Plugin/Type/LegacyDiscoveryDecorator.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/LegacyDiscoveryDecorator.php
@@ -74,2 +74,3 @@
   }
+
 }
diff -u b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetBase.php b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetBase.php
--- b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetBase.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetBase.php
@@ -45,7 +45,22 @@
    */
   protected $weight;
 
-  public function __construct($plugin_id, DiscoveryInterface $discovery, $instance, array $settings, $weight) {
+  /**
+   * Constructs a WidgetBase object.
+   *
+   * @param array $plugin_id
+   *   The plugin_id for the widget..
+   * @param Drupal\Component\Plugin\Discovery\DiscoveryInterface $discovery
+   *   The Discovery class that holds access to the widget implementation
+   *   definition.
+   * @param Drupal\field\FieldInstance $instance
+   *   The field instance to which the widget is associated.
+   * @param array $settings
+   *   The widget's settings.
+   * @param int $weight
+   *   The widget's weight.
+   */
+  public function __construct($plugin_id, DiscoveryInterface $discovery, FieldInstance $instance, array $settings, $weight) {
     parent::__construct(array(), $plugin_id, $discovery);
 
     $this->instance = $instance;
@@ -430,2 +445,3 @@
   }
+
 }
diff -u b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetInterface.php b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetInterface.php
--- b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetInterface.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetInterface.php
@@ -135,7 +135,7 @@
    * @param array $form_state
    *   An associative array containing the current state of the form.
    *
-   * @return
+   * @return array
    *   The element on which the error should be flagged.
    */
   public function errorElement(array $element, array $error, array $form, array &$form_state);
diff -u b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetPluginManager.php b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetPluginManager.php
--- b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetPluginManager.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/Widget/WidgetPluginManager.php
@@ -26,6 +26,9 @@
   protected $cache_key = 'field_widget_types';
   protected $hook = 'field_widget_info';
 
+  /**
+   * Constructs a WidgetPluginManager object.
+   */
   public function __construct() {
     $this->baseDiscovery = new LegacyDiscoveryDecorator(new AnnotatedClassDiscovery('field', 'widget'));
     $this->discovery = new CacheDecorator($this->baseDiscovery, $this->cache_key, $this->cache_bin);
diff -u b/core/modules/field/modules/number/lib/Drupal/number/Plugin/field/widget/NumberWidget.php b/core/modules/field/modules/number/lib/Drupal/number/Plugin/field/widget/NumberWidget.php
--- b/core/modules/field/modules/number/lib/Drupal/number/Plugin/field/widget/NumberWidget.php
+++ b/core/modules/field/modules/number/lib/Drupal/number/Plugin/field/widget/NumberWidget.php
@@ -81,2 +81,3 @@
   }
+
 }