Adds option to download only core translations

Author: VangelisP

README.md

@@ -25,6 +25,11 @@ projects installed. It also runs on `composer require` command.
 You can manually download the localization files according to your configuration
 by using `composer drupal:l10n`.
 
+If you only need Drupal core translations (for example so Drush can detect and
+install languages), use:
+
+`composer drupal:l10n --core-only`
+
 ## Configuration
 
 You can configure the plugin by providing some settings in the `extra` section

src/DrupalL10nCommand.php

@@ -24,6 +24,7 @@ protected function configure() {
       ->setDescription('Download Drupal translations files.')
       ->setDefinition([
         new InputOption('no-dev', NULL, InputOption::VALUE_NONE, 'Disables download of translations of require-dev dependencies.'),
+        new InputOption('core-only', NULL, InputOption::VALUE_NONE, 'Downloads translations for Drupal core only (skip contrib modules/themes/profiles).'),
       ]);
   }
 
@@ -32,7 +33,7 @@ protected function configure() {
    */
   protected function execute(InputInterface $input, OutputInterface $output): int {
     $handler = new Handler($this->getComposer(), $this->getIO());
-    $handler->downloadLocalization(!$input->getOption('no-dev'));
+    $handler->downloadLocalization(!$input->getOption('no-dev'), [], $input->getOption('core-only'));
     return 0;
   }
 

src/Handler.php

@@ -28,6 +28,10 @@ class Handler {
     'drupal-theme',
     'drupal-profile',
   ];
+  const DRUPAL_CORE_PACKAGE_NAMES = [
+    'drupal/core',
+    'drupal/drupal',
+  ];
 
   /**
    * The composer object.
@@ -132,8 +136,11 @@ public function onPostCmdEvent(Event $event) {
    *   A list of Packages to download the localization. If empty, the
    *   localization for all Drupal packages detected in the installation will be
    *   downloaded.
+  * @param bool $coreOnly
+  *   TRUE to download Drupal core localization only. FALSE to include contrib
+  *   projects.
    */
-  public function downloadLocalization($dev = TRUE, array $packages = []) {
+  public function downloadLocalization($dev = TRUE, array $packages = [], $coreOnly = FALSE) {
     $drupal_core_package = $this->getDrupalCorePackage();
     // Ensure drupal core package is present.
     if (is_null($drupal_core_package)) {
@@ -149,6 +156,10 @@ public function downloadLocalization($dev = TRUE, array $packages = []) {
       $packages = $this->composer->getRepositoryManager()->getLocalRepository()->getPackages();
     }
     foreach ($packages as $package) {
+      if ($coreOnly && !in_array($package->getName(), self::DRUPAL_CORE_PACKAGE_NAMES)) {
+        continue;
+      }
+
       // Filter by the type of package.
       if (in_array($package->getType(), $this::DRUPAL_L10N_PACKAGE_TYPES)) {
         // Include development project or not.

tests/PluginTest.php

@@ -143,6 +143,34 @@ public function testContribmodules() {
     $this->assertFileExists($semver_fr_translation_file, 'French translations file should exist.');
   }
 
+  /**
+   * Tests that core-only option skips contrib translations.
+   */
+  public function testCoreOnlyOption() {
+    $core_version = '9.5.3';
+    $contrib_module = 'entity_share';
+    $contrib_composer_version = '3.0.0-rc4';
+    $contrib_drupal_version = '8.x-3.0-rc4';
+    $translations_directory = $this->tmpDir . DIRECTORY_SEPARATOR . 'translations' . DIRECTORY_SEPARATOR . 'contrib';
+    $core_translation_file = $translations_directory . DIRECTORY_SEPARATOR . 'drupal-' . $core_version . '.fr.po';
+    $contrib_translation_file = $translations_directory . DIRECTORY_SEPARATOR . $contrib_module . '-' . $contrib_drupal_version . '.fr.po';
+
+    $this->composer('install');
+    $this->composer('require --update-with-dependencies drupal/core:"' . $core_version . '"');
+    $this->composer('require drupal/' . $contrib_module . ':"' . $contrib_composer_version . '"');
+    $this->assertFileExists($core_translation_file, 'Drupal core translation should exist after install.');
+    $this->assertFileExists($contrib_translation_file, 'Contrib translation should exist after install.');
+
+    $this->fs->remove($core_translation_file);
+    $this->fs->remove($contrib_translation_file);
+    $this->assertFileDoesNotExist($core_translation_file, 'Drupal core translation should not exist after removal.');
+    $this->assertFileDoesNotExist($contrib_translation_file, 'Contrib translation should not exist after removal.');
+
+    $this->composer('drupal:l10n --core-only');
+    $this->assertFileExists($core_translation_file, 'Drupal core translation should exist after --core-only command.');
+    $this->assertFileDoesNotExist($contrib_translation_file, 'Contrib translation should not exist after --core-only command.');
+  }
+
   /**
    * Tests that on Drupal 7, core and contrib modules are handled.
    */