added drush 9 compatibility

drush.services.yml

@@ -0,0 +1,6 @@
+services:
+  custom_purge.commands:
+    class: \Drupal\custom_purge\Commands\CustomPurgeCommands
+    arguments: ['@custom_purge.url_purger']
+    tags:
+      - { name: drush.command }

src/Commands/CustomPurgeCommands.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Drupal\custom_purge\Commands;
+
+use Drupal\custom_purge\UrlPurger;
+use Drush\Commands\DrushCommands;
+
+/**
+ * A Drush commandfile.
+ *
+ * In addition to this file, you need a drush.services.yml
+ * in root of your module, and a composer.json file that provides the name
+ * of the services file to use.
+ *
+ * See these files for an example of injecting Drupal services:
+ *   - http://cgit.drupalcode.org/devel/tree/src/Commands/DevelCommands.php
+ *   - http://cgit.drupalcode.org/devel/tree/drush.services.yml
+ */
+class CustomPurgeCommands extends DrushCommands {
+
+  /**
+   * The UrlPurger.
+   *
+   * @var \Drupal\custom_purge\UrlPurger
+   */
+  protected $urlPurger;
+
+  /**
+   * Construct of CustomPurgeCommands.
+   *
+   * @param \Drupal\custom_purge\UrlPurger $url_purger
+   *   The custom purge url purger.
+   */
+  public function __construct(UrlPurger $url_purger) {
+    parent::__construct();
+    $this->urlPurger = $url_purger;
+  }
+
+  /**
+   * Calls the purgeAllProviders method.
+   *
+   * @param string $url
+   *   The url to purge.
+   * @command custom-purge-all-providers
+   */
+  function drushCustomPurgeAllProviders(string $url) {
+    $this->logger->info($url);
+    $url_array = explode(',', $url);
+    $purger = $this->urlPurger;
+    $purger->purgeAllProviders($url_array);
+  }
+
+}