Delete plugin translation files when plugin is uninstalled (#339)

* Delete plugin translation files

* Always call `uninstall_plugin()` to restore existing behavior

* Add tests for language pack cleanup behavior

* Fix PHPCS issues

* Add `wp-cli/language-command` as a dev dependency

* Fix the `@require` tag

Co-authored-by: Daniel Bachhuber <daniel.bachhuber@automattic.com>

composer.json

@@ -23,6 +23,7 @@
     "require-dev": {
         "wp-cli/cache-command": "^2.0",
         "wp-cli/entity-command": "^1.3 || ^2",
+        "wp-cli/language-command": "^2.0",
         "wp-cli/scaffold-command": "^1.2 || ^2",
         "wp-cli/wp-cli-tests": "^3.1"
     },

features/plugin-uninstall.feature

@@ -91,3 +91,26 @@ Feature: Uninstall a WordPress plugin
       Success:
       """
     And the return code should be 0
+
+  @require-wp-5.2
+  Scenario: Uninstalling a plugin should remove its language pack too
+    Given a WP install
+    And I run `wp plugin install wordpress-importer`
+    And I run `wp core language install fr_FR`
+    And I run `wp site switch-language fr_FR`
+
+    When I run `wp language plugin install wordpress-importer fr_FR`
+    Then STDOUT should contain:
+      """
+      Success:
+      """
+    And the wp-content/languages/plugins/wordpress-importer-fr_FR.mo file should exist
+    And the wp-content/languages/plugins/wordpress-importer-fr_FR.po file should exist
+
+    When I run `wp plugin uninstall wordpress-importer`
+    Then STDOUT should contain:
+      """
+      Success:
+      """
+    And the wp-content/languages/plugins/wordpress-importer-fr_FR.mo file should not exist
+    And the wp-content/languages/plugins/wordpress-importer-fr_FR.po file should not exist

src/Plugin_Command.php

@@ -954,6 +954,33 @@ public function uninstall( $args, $assoc_args = array() ) {
 
 			uninstall_plugin( $plugin->file );
 
+			$plugin_translations = wp_get_installed_translations( 'plugins' );
+
+			$plugin_slug = dirname( $plugin->file );
+
+			if ( 'hello.php' === $plugin->file ) {
+				$plugin_slug = 'hello-dolly';
+			}
+
+			// Remove language files, silently.
+			if ( '.' !== $plugin_slug && ! empty( $plugin_translations[ $plugin_slug ] ) ) {
+				$translations = $plugin_translations[ $plugin_slug ];
+
+				global $wp_filesystem;
+				require_once ABSPATH . '/wp-admin/includes/file.php';
+				WP_Filesystem();
+
+				foreach ( $translations as $translation => $data ) {
+					$wp_filesystem->delete( WP_LANG_DIR . '/plugins/' . $plugin_slug . '-' . $translation . '.po' );
+					$wp_filesystem->delete( WP_LANG_DIR . '/plugins/' . $plugin_slug . '-' . $translation . '.mo' );
+
+					$json_translation_files = glob( WP_LANG_DIR . '/plugins/' . $plugin_slug . '-' . $translation . '-*.json' );
+					if ( $json_translation_files ) {
+						array_map( array( $wp_filesystem, 'delete' ), $json_translation_files );
+					}
+				}
+			}
+
 			if ( ! Utils\get_flag_value( $assoc_args, 'skip-delete' ) && $this->delete_plugin( $plugin ) ) {
 				WP_CLI::log( "Uninstalled and deleted '$plugin->name' plugin." );
 			} else {