updated serial field

2016-11-05 17:58:43 +01:00
parent 252abe9b0e
commit c70a4bed11
6 changed files with 570 additions and 184 deletions
--- a/sites/all/modules/contrib/fields/serial/serial.inc
+++ b/sites/all/modules/contrib/fields/serial/serial.inc
@@ -41,29 +41,31 @@ function _serial_drop_table(array $field, array $instance) {
 }

 /**
- * Renames serial table(s) when a content type us renamed.
+ * Renames serial table(s) when a entity bundle us renamed.
 *
- * @param string $old_type
- *   An old node type machine name.
- * @param string $new_type
- *   A new node type machine name.
+ * @param string $entity_type
+ *   Type of entity.
+ * @param string $bundle_old
+ *   An old entity bundle machine name.
+ * @param string $bundle_new
+ *   A new entity bundle machine name.
 */
-function _serial_rename_tables($old_type, $new_type) {
+function _serial_rename_tables($entity_type, $bundle_old, $bundle_new) {
  // Build the query to find all affected tables.
  $query = db_select('field_config', 'f')
    ->fields('f', array('field_name'));

-  $query->join(
-    'field_config_instance',
-    'i',
-    "f.field_name = i.field_name AND f.type = 'serial' AND i.bundle = '$new_type'"
-  );
+  $query->join('field_config_instance', 'i', '(f.field_name = i.field_name)');
+
+  $query->condition('f.type', SERIAL_FIELD_TYPE);
+  $query->condition('i.entity_type', $entity_type);
+  $query->condition('i.bundle', $bundle_new);

  // Rename each affected table.
  foreach ($query->addTag('node_access')->execute() as $record) {
    db_rename_table(
-      _serial_get_table_name($old_type, $record->field_name),
-      _serial_get_table_name($new_type, $record->field_name)
+      _serial_get_table_name($entity_type, $bundle_old, $record->field_name),
+      _serial_get_table_name($entity_type, $bundle_new, $record->field_name)
    );
  }
 }
@@ -80,22 +82,26 @@ function _serial_rename_tables($old_type, $new_type) {
 *   The name of the assistant table of the specified field instance.
 */
 function _serial_get_field_table_name(array $field, array $instance) {
-  return _serial_get_table_name($instance['bundle'], $field['field_name']);
+  return _serial_get_table_name($instance['entity_type'], $instance['bundle'], $field['field_name']);
 }

 /**
 * Gets the name of the assistant table for a specific field.
 *
+ * @param string $entity_type
+ *   Type of entity (e.g. node)
 * @param string $bundle
- *   The name of the entity type that contains the field.
+ *   The name of the entity type that contains the field (e.g. content type)
 * @param string $field_name
 *   The name of the field.
 *
 * @return string
- *   the name of the assistant table of the specified field.
+ *   The name of the assistant table of the specified field.
 */
-function _serial_get_table_name($bundle, $field_name) {
-  return db_escape_table('serial_' . $bundle . '_' . $field_name);
+function _serial_get_table_name($entity_type, $bundle, $field_name) {
+  // Remember about max length of MySQL tables - 64 symbols.
+  // @todo Think about improvement for this.
+  return db_escape_table('serial_' . md5("{$entity_type}_{$bundle}_{$field_name}"));
 }

 /**
@@ -108,17 +114,18 @@ function _serial_get_table_schema() {
  return array(
    'fields' => array(
      'sid' => array(
-        'type' => 'serial',
-        'unsigned' => TRUE,
+        'type' => SERIAL_FIELD_TYPE,
        'not null' => TRUE,
+        'unsigned' => TRUE,
        'description' => 'The atomic serial field.',
      ),
      'uniqid' => array(
-        'description' => 'Unique temporary allocation Id.',
        'type' => 'varchar',
        'length' => 23,
+        'default' => '',
        'not null' => TRUE,
-        'default' => ''),
+        'description' => 'Unique temporary allocation Id.',
+      ),
    ),
    'primary key' => array('sid'),
    'unique keys' => array(
@@ -128,8 +135,10 @@ function _serial_get_table_schema() {
 }

 /**
- * Generates a unique serial value (unique per node type).
+ * Generates a unique serial value (unique per entity bundle).
 *
+ * @param string $entity_type
+ *   Type of entity (e.g. node)
 * @param string $bundle
 *   Containing bundle (e.g. content type).
 * @param string $field_name
@@ -139,76 +148,102 @@ function _serial_get_table_schema() {
 *
 * @return int
 *   the unique serial value number.
+ *
+ * @throws \Exception
 */
-function _serial_generate_value($bundle, $field_name, $delete = TRUE) {
-  // Get the name of the relevant table.
-  $table = _serial_get_table_name($bundle, $field_name);
+function _serial_generate_value($entity_type, $bundle, $field_name, $delete = TRUE) {
+  $transaction = db_transaction();

-  // Insert a temporary record to get a new unique serial value.
-  $uniqid = uniqid('', TRUE);
-  $sid = db_insert($table)
-    ->fields(array('uniqid' => $uniqid))
-    ->execute();
-
-  // If there's a reason why it's come back undefined, reset it.
-  $sid = isset($sid) ? $sid : 0;
-
-  // Delete the temporary record.
-  if ($delete && ($sid % 10) == 0) {
-    db_delete($table)
-      ->condition('uniqid', $uniqid)
+  try {
+    // Get the name of the relevant table.
+    $table = _serial_get_table_name($entity_type, $bundle, $field_name);
+    // Insert a temporary record to get a new unique serial value.
+    $uniqid = uniqid('', TRUE);
+    $sid = db_insert($table)
+      ->fields(array('uniqid' => $uniqid))
      ->execute();
-  }

-  // Return the new unique serial value.
-  return $sid;
+    // If there's a reason why it's come back undefined, reset it.
+    $sid = isset($sid) ? $sid : 0;
+
+    // Delete the temporary record.
+    if ($delete && $sid && ($sid % 10) == 0) {
+      db_delete($table)
+        ->condition('sid', $sid, '<')
+        ->execute();
+    }
+
+    // Return the new unique serial value.
+    return $sid;
+  }
+  catch (Exception $e) {
+    $transaction->rollback();
+    watchdog_exception('serial', $e);
+    throw $e;
+  }
 }

 /**
- * Initializes the value of a new serial field in existing nodes.
- *
- * @todo Currently works only for nodes - should support comments and users.
+ * Initializes the value of a new serial field in existing entities.
 *
+ * @param string $entity_type
+ *   Type of entity (e.g. node)
 * @param string $bundle
 *   Containing bundle (e.g. content type).
 * @param string $field_name
 *   The field name.
 *
 * @return int
- *   Number of existing nodes that have been initialized.
+ *   Number of existing entities that have been initialized.
 */
-function _serial_init_old_nodes($bundle, $field_name) {
-  $nodes = node_load_multiple(array(), array('type' => $bundle));
+function _serial_init_old_entities($entity_type, $bundle, $field_name) {
+  $query = new EntityFieldQuery();
+  $query->entityCondition('entity_type', $entity_type)
+    ->fieldCondition($field_name);

-  // Allocate a serial number for every old node.
-  foreach ($nodes as $node) {
-    $node->{$field_name} = array(
-      LANGUAGE_NONE => array(
-        array(
-          'value' => _serial_generate_value($bundle, $field_name, FALSE),
-        ),
-      ),
-    );
-
-    node_save($node);
+  // The "comment" entity type does not support bundle conditions.
+  // @see https://api.drupal.org/api/drupal/includes!entity.inc/function/EntityFieldQuery%3A%3AentityCondition/7
+  if ('comment' !== $entity_type) {
+    $query->entityCondition('bundle', $bundle);
  }

-  // Return the number of existing nodes that have been initialized.
-  return count($nodes);
+  $results = $query->execute();
+
+  if (!empty($results[$entity_type])) {
+    foreach ($results[$entity_type] as $entity) {
+      list($id, , $bundle) = entity_extract_ids($entity_type, $entity);
+
+      $entity = entity_load_unchanged($entity_type, $id);
+      $entity->{$field_name} = array(
+        LANGUAGE_NONE => array(
+          array(
+            'value' => _serial_generate_value($entity_type, $bundle, $field_name, FALSE),
+          ),
+        ),
+      );
+
+      field_attach_insert($entity_type, $entity);
+    }
+
+    return count($results[$entity_type]);
+  }
+
+  return 0;
 }

 /**
 * Retrieves all the managed serial fields.
 *
- * @return array
- *   Pairs of node type name, field name.
+ * @return string[]
+ *   Result set containing entity type, entity bundle, field name.
 */
 function _serial_get_all_fields() {
  $query = db_select('field_config', 'f');
  $query->join('field_config_instance', 'i', 'i.field_name = f.field_name');

-  return $query->fields('i', array('bundle', 'field_name'))
-    ->condition('f.type', 'serial')
+  return $query
+    ->fields('i', array('entity_type', 'bundle', 'field_name'))
+    ->condition('f.type', SERIAL_FIELD_TYPE)
    ->condition('i.deleted', 0)
    ->execute()
    ->fetchAll();
--- a/sites/all/modules/contrib/fields/serial/serial.info
+++ b/sites/all/modules/contrib/fields/serial/serial.info
@@ -1,14 +1,16 @@
 name = Serial
 description = Defines atomic auto increment (serial) field type.
-package = Fields
+package = Field
 core = 7.x
+
+files[] = tests/serial.test
+files[] = tests/serial.fields.inc
+
 dependencies[] = field
-files[] = serial.module

-
-; Information added by Drupal.org packaging script on 2015-05-19
-version = "7.x-1.4"
+; Information added by Drupal.org packaging script on 2016-08-31
+version = "7.x-1.8"
 core = "7.x"
 project = "serial"
-datestamp = "1432026177"
+datestamp = "1472678341"

--- a/sites/all/modules/contrib/fields/serial/serial.install
+++ b/sites/all/modules/contrib/fields/serial/serial.install
@@ -7,7 +7,7 @@
 /**
 * Implements hook_field_schema().
 */
-function serial_field_schema($field) {
+function serial_field_schema(array $field) {
  $columns = array();

  switch ($field['type']) {
@@ -37,7 +37,7 @@ function serial_schema() {
  $schema = array();

  foreach (_serial_get_all_fields() as $field) {
-    $schema[_serial_get_table_name($field->bundle, $field->field_name)] = $table_schema;
+    $schema[_serial_get_table_name($field->entity_type, $field->bundle, $field->field_name)] = $table_schema;
  }

  // Return the schema of all the assistant tables (one per field instance).
@@ -57,7 +57,7 @@ function serial_update_7130() {
  // Update the schema of old assistant tables.
  foreach (_serial_get_all_fields() as $field) {
    // Empty the table.
-    $table = _serial_get_table_name($field->bundle, $field->field_name);
+    $table = _serial_get_table_name($field->entity_type, $field->bundle, $field->field_name);
    db_delete($table)->execute();

    // Drop nid field and key.
@@ -69,3 +69,30 @@ function serial_update_7130() {
    db_add_unique_key($table, 'uniqid', array('uniqid'));
  }
 }
+
+/**
+ * Add 'node_' to all existing serial tables.
+ *
+ * Change name:
+ *   from: serial_{content_type}_{field_name}
+ *   to: serial_node_{content_type}_{field_name}
+ */
+function serial_update_7131() {
+  // All old serial tables are of 'node' entity type.
+  foreach (db_find_tables('serial_%') as $table) {
+    db_rename_table($table, preg_replace('/^serial_/', 'serial_node_', $table));
+  }
+}
+
+/**
+ * Reorganize table names to prevent collisions with long names.
+ */
+function serial_update_7132() {
+  module_load_include('inc', 'serial');
+
+  foreach (db_find_tables('serial_%') as $table) {
+    // Explode by underscores and match old format.
+    list(, $entity_type, $bundle, $field_name) = explode('_', $table, 4);
+    db_rename_table($table, _serial_get_table_name($entity_type, $bundle, $field_name));
+  }
+}
--- a/sites/all/modules/contrib/fields/serial/serial.module
+++ b/sites/all/modules/contrib/fields/serial/serial.module
@@ -4,110 +4,35 @@
 * The Serial module main file.
 */

+define('SERIAL_FIELD_TYPE', 'serial');
+
 /**
 * Implements hook_field_info().
 */
 function serial_field_info() {
  return array(
-    'serial' => array(
+    SERIAL_FIELD_TYPE => array(
      'label' => t('Serial'),
      'description' => t('Auto increment serial field type.'),
      // The "property_type" should be defined for accessing the
      // field by entity metadata wrapper.
-      'property_type' => 'serial',
-      'default_widget' => 'serial',
+      'property_type' => 'integer',
+      'default_widget' => 'serial_widget_default',
      'default_formatter' => 'serial_formatter_default',
    ),
  );
 }

 /**
- * Implements hook_field_create_instance().
+ * Implements hook_field_widget_info().
 */
-function serial_field_create_instance($instance) {
-  $field = field_read_field($instance['field_name']);
-
-  if ('serial' == $field['type']) {
-    // Create the assistant table:
-    module_load_include('inc', 'serial');
-    _serial_create_table($field, $instance);
-
-    // Set serial values for old objects.
-    $old_count = _serial_init_old_nodes($instance['bundle'], $field['field_name']);
-
-    if ($old_count > 0) {
-      drupal_set_message(t('Serial values have been automatically set for %count existing nodes.', array(
-        '%count' => $old_count,
-      )));
-    }
-  }
-}
-
-/**
- * Implements hook_field_delete_instance().
- */
-function serial_field_delete_instance($instance) {
-  $field = field_read_field($instance['field_name']);
-
-  if ('serial' == $field['type']) {
-    // Drop the assistant table.
-    module_load_include('inc', 'serial');
-    _serial_drop_table($field, $instance);
-  }
-}
-
-/**
- * Implements hook_form_alter().
- */
-function serial_form_alter(&$form, $form_state, $form_id) {
-  if ('field_ui_field_settings_form' == $form_id && 'serial' == $form['field']['type']['#value']) {
-    drupal_set_message(t('Serial field %field has been created.', array(
-      '%field' => $form['field']['field_name']['#value'],
-    )));
-
-    drupal_goto("admin/structure/types/manage/{$form['#bundle']}/fields");
-  }
-}
-
-/**
- * Implements hook_field_presave().
- */
-function serial_field_presave($entity_type, $entity, $field, $instance, $langcode, &$items) {
-  if (empty($items)) {
-    module_load_include('inc', 'serial');
-
-    $items = array(array('value' => _serial_generate_value($instance['bundle'], $field['field_name'])));
-  }
-}
-
-/**
- * Implements hook_field_is_empty().
- */
-function serial_field_is_empty($item, $field) {
-  // Never should be treated as empty.
-  return FALSE;
-}
-
-/**
- * Implements hook_node_presave().
- */
-function serial_node_presave($node) {
-  if (module_exists('auto_nodetitle')) {
-    if (auto_nodetitle_get_setting($node->type)) {
-      auto_nodetitle_set_title($node);
-    }
-  }
-}
-
-/**
- * Implements hook_node_type_update().
- */
-function serial_node_type_update($info) {
-  // Handle content type rename:
-  if (isset($info->old_type) && ($info->old_type != $info->type)) {
-    module_load_include('inc', 'serial');
-    _serial_rename_tables($info->old_type, $info->type);
-  }
+function serial_field_widget_info() {
+  return array(
+    'serial_widget_default' => array(
+      'label' => t('Hidden (Automatic)'),
+      'field types' => array(SERIAL_FIELD_TYPE),
+    ),
+  );
 }

 /**
@@ -117,15 +42,95 @@ function serial_field_formatter_info() {
  return array(
    'serial_formatter_default' => array(
      'label' => t('Default'),
-      'field types' => array('serial'),
+      'field types' => array(SERIAL_FIELD_TYPE),
    ),
  );
 }

+/**
+ * Implements hook_field_create_instance().
+ */
+function serial_field_create_instance(array $instance) {
+  $field = field_read_field($instance['field_name']);
+
+  if (SERIAL_FIELD_TYPE === $field['type']) {
+    // Create the assistant table:
+    module_load_include('inc', 'serial');
+    _serial_create_table($field, $instance);
+
+    // Set serial values for old objects.
+    $old_count = _serial_init_old_entities($instance['entity_type'], $instance['bundle'], $field['field_name']);
+
+    if ($old_count > 0) {
+      drupal_set_message(t('Serial values have been automatically set for %count existing entities.', array(
+        '%count' => $old_count,
+      )));
+    }
+  }
+}
+
+/**
+ * Implements hook_field_delete_instance().
+ */
+function serial_field_delete_instance(array $instance) {
+  $field = field_read_field($instance['field_name']);
+
+  if (SERIAL_FIELD_TYPE == $field['type']) {
+    // Drop the assistant table.
+    module_load_include('inc', 'serial');
+    _serial_drop_table($field, $instance);
+  }
+}
+
+/**
+ * Implements hook_field_presave().
+ */
+function serial_field_presave($entity_type, $entity, array $field, array $instance, $langcode, array &$items) {
+  if (empty($items)) {
+    module_load_include('inc', 'serial');
+
+    $items[] = array(
+      'value' => _serial_generate_value($entity_type, $instance['bundle'], $field['field_name']),
+    );
+  }
+}
+
+/**
+ * Implements hook_field_is_empty().
+ */
+function serial_field_is_empty($item, $field) {
+  // Never should be treated as empty.
+  return empty($item['value']);
+}
+
+/**
+ * Implements hook_clone_node_alter().
+ */
+function serial_clone_node_alter(stdClass $node) {
+  // Reset values of all serial fields when cloning a node.
+  foreach (field_info_instances('node', $node->type) as $field_name => $instance) {
+    $info = field_info_field($field_name);
+
+    if ('serial' === $info['type']) {
+      $node->{$field_name} = array();
+    }
+  }
+}
+
+/**
+ * Implements hook_field_attach_rename_bundle().
+ */
+function serial_field_attach_rename_bundle($entity_type, $bundle_old, $bundle_new) {
+  if ($bundle_old !== $bundle_new) {
+    module_load_include('inc', 'serial');
+    _serial_rename_tables($entity_type, $bundle_old, $bundle_new);
+  }
+}
+
 /**
 * Implements hook_field_formatter_view().
 */
-function serial_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
+function serial_field_formatter_view($entity_type, $entity, array $field, array $instance, $langcode, array $items, array $display) {
  $element = array();

  // Define the field contents for the single default formatter.
@@ -157,30 +162,28 @@ function serial_theme() {
 /**
 * Theme function for the default formatter.
 */
-function theme_serial_formatter_default($variables) {
+function theme_serial_formatter_default(array $variables) {
  return $variables['serial_id'];
 }

 /**
- * Implements hook_field_widget_info().
+ * Implements hook_field_widget_form().
 */
-function serial_field_widget_info() {
-  return array(
-    'serial' => array(
-      'label' => t('Hidden (Automatic)'),
-      'field types' => array('serial'),
-    ),
-  );
-}
+function serial_field_widget_form(
+  array &$form,
+  array &$form_state,
+  array $field,
+  array $instance,
+  $langcode,
+  array $items,
+  $delta,
+  array $element
+) {
+  $element['#type'] = 'hidden';

-/**
- * Implements hook_field_widget().
- */
-function serial_field_widget(&$form, &$form_state, $field, $instance, $items, $delta = 0) {
-  return array(
-    'value' => array(
-      '#type' => 'hidden',
-      '#default_value' => $items[$delta]['value'],
-    ),
-  );
+  if (isset($items[$delta]['value'])) {
+    $element['#default_value'] = $items[$delta]['value'];
+  }
+
+  return array('value' => $element);
 }
--- a/sites/all/modules/contrib/fields/serial/tests/serial.fields.inc
+++ b/sites/all/modules/contrib/fields/serial/tests/serial.fields.inc
@@ -0,0 +1,191 @@
+<?php
+/**
+ * @file
+ * Serial (Fields Helper).
+ */
+
+/**
+ * Class SerialFields.
+ */
+class SerialFields {
+
+  private $fields = array();
+  private $instances = array();
+
+  /**
+   * Set field definitions.
+   *
+   * @param array[] $fields
+   *   An associative array where keys - field names and values - definition.
+   */
+  public function __construct(array $fields) {
+    $this->fields = $fields;
+  }
+
+  /**
+   * Create fields.
+   *
+   * @return self
+   *   Object instance.
+   *
+   * @throws \FieldException
+   *   When cannot create a field.
+   */
+  public function create() {
+    foreach ($this->fields as $name => $data) {
+      if (!db_table_exists("field_data_$name")) {
+        field_create_field($data + array(
+          'default' => '',
+          'not null' => TRUE,
+          'field_name' => $name,
+        ));
+      }
+    }
+
+    return $this;
+  }
+
+  /**
+   * Completely delete fields.
+   *
+   * This function deletes tables: "field_data_NAME" and "field_revision_NAME"
+   * and entries in "field_config" and "field_config_instances".
+   *
+   * @return self
+   *   Object instance.
+   */
+  public function delete() {
+    foreach (array_keys($this->fields) as $name) {
+      // Delete tables.
+      foreach (array('data', 'revision') as $table_type) {
+        $table = "field_{$table_type}_{$name}";
+
+        if (db_table_exists($table)) {
+          db_drop_table($table);
+        }
+      }
+
+      // Delete entries.
+      foreach (array('config', 'config_instance') as $table_type) {
+        db_delete("field_$table_type")
+          ->condition('field_name', $name)
+          ->execute();
+      }
+    }
+
+    return $this;
+  }
+
+  /**
+   * Attach existing fields into entity.
+   *
+   * @param string $entity_type
+   *   Entity machine name.
+   * @param string $bundle_name
+   *   Entity bundle name.
+   *
+   * @return self
+   *   Object instance.
+   *
+   * @throws \FieldException
+   *   When instance cannot be created.
+   */
+  public function attach($entity_type, $bundle_name) {
+    $attached_fields = field_info_instances($entity_type, $bundle_name);
+
+    foreach ($this->fields as $field_name => $data) {
+      if (empty($attached_fields[$field_name]) && field_info_field($field_name)) {
+        // Provide a possibility to specify field weight, depending on
+        // another one.
+        //
+        // @code
+        // $fields = array(
+        //   'field_title' => array(
+        //     'type' => 'text',
+        //     'label' => 'Title',
+        //     'widget' => array(
+        //       'weight' => 10,
+        //     ),
+        //   ),
+        //   'field_description' => array(
+        //     'type' => 'text',
+        //     'label' => 'Description',
+        //     'widget' => array(
+        //       // Weight of this field will be "9".
+        //       'weight' => array('field_title', -1),
+        //     ),
+        //   ),
+        // );
+        // @endcode
+        if (isset($data['widget']['weight']) && is_array($data['widget']['weight'])) {
+          list($dependent, $calc) = $data['widget']['weight'];
+
+          $dependent = field_info_instance($entity_type, $dependent, $bundle_name);
+
+          if (!empty($dependent)) {
+            $data['widget']['weight'] = $dependent['widget']['weight'] + $calc;
+          }
+        }
+
+        field_create_instance($data + array(
+          'bundle' => $bundle_name,
+          'field_name' => $field_name,
+          'entity_type' => $entity_type,
+        ));
+      }
+    }
+
+    return $this;
+  }
+
+  /**
+   * Get field instances.
+   *
+   * @return array[]
+   *   Field instances.
+   */
+  public function &getInstances() {
+    if (empty($this->instances)) {
+      $query = db_select('field_config_instance', 'fci')
+        ->fields('fci', array('field_name', 'data'))
+        ->condition('field_name', array_keys($this->fields))
+        ->execute()
+        ->fetchAllKeyed();
+
+      $this->instances = array_map('unserialize', $query);
+    }
+
+    return $this->instances;
+  }
+
+  /**
+   * Field definitions getter.
+   *
+   * @return array[]
+   *   Field definitions.
+   */
+  public function getFields() {
+    return $this->fields;
+  }
+
+  /**
+   * Save field instances.
+   *
+   * @return self
+   *   Object instance.
+   *
+   * @throws \Exception
+   * @throws \InvalidMergeQueryException
+   */
+  public function saveInstances() {
+    foreach ($this->instances as $field_name => $data) {
+      db_merge('field_config_instance')
+        ->fields(array('data' => serialize($data)))
+        ->condition('field_name', $field_name)
+        ->execute();
+    }
+
+    return $this;
+  }
+
+}
--- a/sites/all/modules/contrib/fields/serial/tests/serial.test
+++ b/sites/all/modules/contrib/fields/serial/tests/serial.test
@@ -0,0 +1,128 @@
+<?php
+/**
+ * @file
+ * Test Serial functionality.
+ */
+
+/**
+ * Class SerialTestCase.
+ */
+class SerialTestCase extends DrupalWebTestCase {
+
+  const CONTENT_TYPE = 'serial_test_content_type';
+
+  /**
+   * @var \SerialFields
+   */
+  private $fields;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getInfo() {
+    return array(
+      'name' => 'Serial Field',
+      'group' => 'Field',
+      'description' => 'Testing serial field functionality.',
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp('serial', 'comment');
+
+    $this->drupalCreateContentType(array('type' => static::CONTENT_TYPE));
+
+    $this->fields = new SerialFields(array(
+      'serial' => array(
+        'type' => SERIAL_FIELD_TYPE,
+        'label' => 'Serial',
+        'settings' => array(),
+      ),
+    ));
+
+    $this->fields
+      ->create()
+      // Attach serial field to content type and comments form.
+      ->attach('node', static::CONTENT_TYPE)
+      ->attach('comment', 'comment_node_' . static::CONTENT_TYPE);
+
+    // Grant all known permissions for user.
+    $this->drupalLogin($this->drupalCreateUser(array_keys(module_invoke_all('permission'))));
+  }
+
+  /**
+   * Create N nodes and attach N comments for the last.
+   *
+   * @param int $nodes
+   *   Number of nodes for creation.
+   * @param int $comments
+   *   Number of comments for creation.
+   */
+  public function testSerial($nodes = 15, $comments = 6) {
+    for ($i = 0; $i < $nodes; $i++) {
+      // Open form for add new node.
+      $this->visit('node/add/' . str_replace('_', '-', static::CONTENT_TYPE));
+      // Submit new node with filled title.
+      $this->drupalPost(NULL, array('title' => "Node $i"), t('Save'));
+    }
+
+    // Go to editing of the last created node.
+    $this->visit("node/$nodes/edit");
+    // Check that last created node number equal to serial ID.
+    $this->assertSerialField($nodes);
+    // Go to viewing of the last created node.
+    $this->visit("node/$nodes");
+
+    // Post comments for last created node.
+    for ($i = 0; $i < $comments; $i++) {
+      $this->drupalPost(NULL, array(self::fieldName('comment_body') => "Comment $i"), t('Save'));
+    }
+
+    // Go to editing of the last created comment.
+    $this->visit("comment/$comments/edit");
+    // Ensure the last-posted comment number equal to serial ID.
+    $this->assertSerialField($comments);
+  }
+
+  /**
+   * Assert number with value of the serial field on the page.
+   *
+   * @param int $number
+   *   The number for verification.
+   */
+  private function assertSerialField($number) {
+    $this->assertFieldByXPath($this->constructFieldXpath('name', self::fieldName('serial')), $number);
+  }
+
+  /**
+   * Visit path and assert response code.
+   *
+   * @param string $path
+   *   Path to visit.
+   * @param int $code
+   *   Expected response code.
+   */
+  private function visit($path, $code = 200) {
+    $this->drupalGet($path);
+    $this->assertResponse($code);
+  }
+
+  /**
+   * Convert Drupal field name into HTML.
+   *
+   * @param string $name
+   *   Drupal field name.
+   * @param string $column
+   *   Field column.
+   *
+   * @return string
+   *   HTML input name.
+   */
+  private static function fieldName($name, $column = 'value') {
+    return $name . '[' . LANGUAGE_NONE . '][0][' . $column . ']';
+  }
+
+}