diff -u b/core/modules/file/src/Plugin/migrate/destination/EntityFile.php b/core/modules/file/src/Plugin/migrate/destination/EntityFile.php
--- b/core/modules/file/src/Plugin/migrate/destination/EntityFile.php
+++ b/core/modules/file/src/Plugin/migrate/destination/EntityFile.php
@@ -3,23 +3,12 @@
 namespace Drupal\file\Plugin\migrate\destination;
 
 use Drupal\Component\Utility\Unicode;
-use Drupal\Core\Entity\EntityManagerInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Field\FieldTypePluginManagerInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\UriItem;
-use Drupal\Core\File\FileSystemInterface;
-use Drupal\Core\StreamWrapper\LocalStream;
-use Drupal\Core\StreamWrapper\StreamWrapperManagerInterface;
-use Drupal\migrate\Plugin\MigrationInterface;
 use Drupal\migrate\Row;
 use Drupal\migrate\MigrateException;
 use Drupal\migrate\Plugin\migrate\destination\EntityContentBase;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
- * Every migration that uses this destination must have an optional
- * dependency on the d6_file migration to ensure it runs first.
- *
  * @MigrateDestination(
  *   id = "entity:file"
  * )
diff -u b/core/modules/file/src/Plugin/migrate/process/FileCopy.php b/core/modules/file/src/Plugin/migrate/process/FileCopy.php
--- b/core/modules/file/src/Plugin/migrate/process/FileCopy.php
+++ b/core/modules/file/src/Plugin/migrate/process/FileCopy.php
@@ -13,7 +13,7 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
- * Process the file url into a D8 compatible URL.
+ * Copy a file from one place into another.
  *
  * @MigrateProcessPlugin(
  *   id = "file_copy"
@@ -109,7 +109,7 @@
    *   (optional) FILE_EXISTS_REPLACE (default) or FILE_EXISTS_RENAME.
    *
    * @return bool
-   *  TRUE on success, FALSE on failure.
+   *   TRUE on success, FALSE on failure.
    */
   protected function writeFile($source, $destination, $replace = FILE_EXISTS_REPLACE) {
     if ($this->configuration['move']) {
@@ -124,13 +124,11 @@
   /**
    * Determines how to handle file conflicts.
    *
-   * @param \Drupal\migrate\Row $row
-   *
    * @return int
    *   Either FILE_EXISTS_REPLACE (default) or FILE_EXISTS_RENAME, depending
    *   on the current configuration.
    */
-  protected function getOverwriteMode(Row $row) {
+  protected function getOverwriteMode() {
     if (!empty($this->configuration['rename'])) {
       return FILE_EXISTS_RENAME;
     }
@@ -148,8 +146,8 @@
    *   The URI or path.
    *
    * @return string|false
-   *  The directory component of the path or URI, or FALSE if it could not
-   *  be determined.
+   *   The directory component of the path or URI, or FALSE if it could not
+   *   be determined.
    */
   protected function getDirectory($uri) {
     $dir = $this->fileSystem->dirname($uri);
@@ -162,7 +160,8 @@
   }
 
   /**
-   * Returns if the source and destination URIs represent identical paths.
+   * Determines if the source and destination URIs represent identical paths.
+   *
    * If either URI is a remote stream, will return FALSE.
    *
    * @param string $source
@@ -171,8 +170,8 @@
    *   The destination URI.
    *
    * @return bool
-   *  TRUE if the source and destination URIs refer to the same physical path,
-   *  otherwise FALSE.
+   *   TRUE if the source and destination URIs refer to the same physical path,
+   *   otherwise FALSE.
    */
   protected function isLocationUnchanged($source, $destination) {
     if ($this->isLocalUri($source) && $this->isLocalUri($destination)) {
@@ -184,7 +183,7 @@
   }
 
   /**
-   * Returns if the given URI or path is considered local.
+   * Determines if the given URI or path is considered local.
    *
    * A URI or path is considered local if it either has no scheme component,
    * or the scheme is implemented by a stream wrapper which extends
diff -u b/core/modules/file/src/Plugin/migrate/process/Urlencode.php b/core/modules/file/src/Plugin/migrate/process/Urlencode.php
--- b/core/modules/file/src/Plugin/migrate/process/Urlencode.php
+++ b/core/modules/file/src/Plugin/migrate/process/Urlencode.php
@@ -13,20 +13,20 @@
  *   id = "urlencode"
  * )
  */
-class Urlencode extends ProcessPluginBase{
+class Urlencode extends ProcessPluginBase {
 
   /**
    * {@inheritdoc}
    */
   public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
-    // Only apply to a full URL
+    // Only apply to a full URL.
     if (strpos($value, '://')) {
       $components = explode('/', $value);
       foreach ($components as $key => $component) {
         $components[$key] = rawurlencode($component);
       }
       $value = implode('/', $components);
-      // Actually, we don't want certain characters encoded
+      // Actually, we don't want certain characters encoded.
       $value = str_replace('%3A', ':', $value);
       $value = str_replace('%3F', '?', $value);
       $value = str_replace('%26', '&', $value);
diff -u b/core/modules/file/tests/src/Unit/Plugin/migrate/process/UrlencodeTest.php b/core/modules/file/tests/src/Unit/Plugin/migrate/process/UrlencodeTest.php
--- b/core/modules/file/tests/src/Unit/Plugin/migrate/process/UrlencodeTest.php
+++ b/core/modules/file/tests/src/Unit/Plugin/migrate/process/UrlencodeTest.php
@@ -42,7 +42,7 @@
   /**
    * Perform the urlencode process plugin over the given value.
    *
-   * @param $value
+   * @param string $value
    *   Url to be encoded.
    *
    * @return string