Issue #3409982 by claudiu.cristea, longwave, alexpott, catch, Ghost of Drupal...

Issue #3409982 by claudiu.cristea, longwave, alexpott, catch, Ghost of Drupal Past: [D10.2 regression] Theme suggestions cannot alter variables anymore

(cherry picked from commit 5bf40faa)

core/lib/Drupal/Core/Render/theme.api.php

@@ -687,7 +687,7 @@ function hook_theme_suggestions_HOOK(array $variables) {
  * node and taxonomy term templates based on the user being logged in.
  *
  * @code
- * function MYMODULE_theme_suggestions_alter(array &$suggestions, array $variables, $hook) {
+ * function MYMODULE_theme_suggestions_alter(array &$suggestions, array &$variables, $hook) {
  *   if (\Drupal::currentUser()->isAuthenticated() && in_array($hook, array('node', 'taxonomy_term'))) {
  *     $suggestions[] = $hook . '__' . 'logged_in';
  *   }
@@ -699,8 +699,8 @@ function hook_theme_suggestions_HOOK(array $variables) {
  *   An array of alternate, more specific names for template files, passed by
  *   reference.
  * @param array $variables
- *   An array of variables passed to the theme hook. Note that this hook is
- *   invoked before any variable preprocessing.
+ *   An array of variables passed to the theme hook, passed by reference. Note
+ *   that this hook is invoked before any variable preprocessing.
  * @param string $hook
  *   The base hook name. For example, if '#theme' => 'node__article' is called,
  *   then $hook will be 'node', not 'node__article'. The specific hook called
@@ -709,7 +709,7 @@ function hook_theme_suggestions_HOOK(array $variables) {
  *
  * @see hook_theme_suggestions_HOOK_alter()
  */
-function hook_theme_suggestions_alter(array &$suggestions, array $variables, $hook) {
+function hook_theme_suggestions_alter(array &$suggestions, array &$variables, $hook) {
   // Add an interface-language specific suggestion to all theme hooks.
   $suggestions[] = $hook . '__' . \Drupal::languageManager()->getCurrentLanguage()->getId();
 }
@@ -750,15 +750,15 @@ function hook_theme_suggestions_alter(array &$suggestions, array $variables, $ho
  * @endcode
  *
  * @param array $suggestions
- *   An array of theme suggestions.
+ *   An array of theme suggestions, passed by reference.
  * @param array $variables
- *   An array of variables passed to the theme hook. Note that this hook is
- *   invoked before any preprocessing.
+ *   An array of variables passed to the theme hook, passed by reference. Note
+ *   that this hook is invoked before any preprocessing.
  *
  * @see hook_theme_suggestions_alter()
  * @see hook_theme_suggestions_HOOK()
  */
-function hook_theme_suggestions_HOOK_alter(array &$suggestions, array $variables) {
+function hook_theme_suggestions_HOOK_alter(array &$suggestions, array &$variables) {
   if (empty($variables['header'])) {
     $suggestions[] = 'hookname__no_header';
   }

core/lib/Drupal/Core/Theme/ThemeManager.php

@@ -368,7 +368,7 @@ public function render($hook, array $variables) {
    * @internal
    *   This method may change at any time. It is not for use outside this class.
    */
-  protected function buildThemeHookSuggestions(string $hook, string $info_base_hook, array $variables): array {
+  protected function buildThemeHookSuggestions(string $hook, string $info_base_hook, array &$variables): array {
     // Set base hook for later use. For example if '#theme' => 'node__article'
     // is called, we run hook_theme_suggestions_node_alter() rather than
     // hook_theme_suggestions_node__article_alter(), and also pass in the base

core/modules/system/tests/modules/theme_suggestions_test/theme_suggestions_test.module

@@ -8,10 +8,11 @@
 /**
  * Implements hook_theme_suggestions_alter().
  */
-function theme_suggestions_test_theme_suggestions_alter(array &$suggestions, array $variables, $hook) {
+function theme_suggestions_test_theme_suggestions_alter(array &$suggestions, array &$variables, $hook) {
   \Drupal::messenger()->addStatus(__FUNCTION__ . '() executed.');
   if ($hook == 'theme_test_general_suggestions') {
     $suggestions[] = $hook . '__module_override';
+    $variables['module_hook'] = 'theme_suggestions_test_theme_suggestions_alter';
   }
 }
 

core/modules/system/tests/modules/theme_test/templates/theme-test-general-suggestions.html.twig

 {# Output for Theme API test #}
 Original template for testing hook_theme_suggestions_alter().
+Hooks: {{ module_hook }} {{ theme_hook }}

core/modules/system/tests/modules/theme_test/theme_test.module

@@ -32,7 +32,7 @@ function theme_test_theme($existing, $type, $theme, $path) {
     'variables' => [],
   ];
   $items['theme_test_general_suggestions'] = [
-    'variables' => [],
+    'variables' => ['module_hook' => 'theme_test_theme', 'theme_hook' => 'none'],
   ];
   $items['theme_test_foo'] = [
     'variables' => ['foo' => NULL],

core/modules/system/tests/src/Functional/Theme/ThemeSuggestionsAlterTest.php

@@ -55,6 +55,7 @@ public function testTemplateSuggestions() {
   public function testGeneralSuggestionsAlter() {
     $this->drupalGet('theme-test/general-suggestion-alter');
     $this->assertSession()->pageTextContains('Original template for testing hook_theme_suggestions_alter().');
+    $this->assertSession()->pageTextContains('Hooks: theme_test_theme none');
 
     // Install test_theme and test that themes can alter template suggestions.
     $this->config('system.theme')
@@ -62,6 +63,7 @@ public function testGeneralSuggestionsAlter() {
       ->save();
     $this->drupalGet('theme-test/general-suggestion-alter');
     $this->assertSession()->pageTextContains('Template overridden based on new theme suggestion provided by the test_theme theme via hook_theme_suggestions_alter().');
+    $this->assertSession()->pageTextContains('Hooks: theme_test_theme test_theme_theme_suggestions_alter');
 
     // Enable the theme_suggestions_test module to test modules implementing
     // suggestions alter hooks.
@@ -69,6 +71,7 @@ public function testGeneralSuggestionsAlter() {
     $this->resetAll();
     $this->drupalGet('theme-test/general-suggestion-alter');
     $this->assertSession()->pageTextContains('Template overridden based on new theme suggestion provided by a module via hook_theme_suggestions_alter().');
+    $this->assertSession()->pageTextContains('Hooks: theme_suggestions_test_theme_suggestions_alter test_theme_theme_suggestions_alter');
   }
 
   /**

core/modules/system/tests/themes/test_theme/templates/theme-test-general-suggestions--module-override.html.twig

 {# Output for Theme API test #}
 Template overridden based on new theme suggestion provided by a module via hook_theme_suggestions_alter().
+Hooks: {{ module_hook }} {{ theme_hook }}

core/modules/system/tests/themes/test_theme/templates/theme-test-general-suggestions--theme-override.html.twig

 {# Output for Theme API test #}
 Template overridden based on new theme suggestion provided by the test_theme theme via hook_theme_suggestions_alter().
+Hooks: {{ module_hook }} {{ theme_hook }}

core/modules/system/tests/themes/test_theme/test_theme.theme

@@ -45,7 +45,7 @@ function test_theme_theme_test_alter_alter(&$data) {
 /**
  * Implements hook_theme_suggestions_alter().
  */
-function test_theme_theme_suggestions_alter(array &$suggestions, array $variables, $hook) {
+function test_theme_theme_suggestions_alter(array &$suggestions, array &$variables, $hook) {
   \Drupal::messenger()->addStatus(__FUNCTION__ . '() executed.');
   // Theme alter hooks run after module alter hooks, so add this theme
   // suggestion to the beginning of the array so that the suggestion added by
@@ -53,6 +53,7 @@ function test_theme_theme_suggestions_alter(array &$suggestions, array $variable
   // enabled.
   if ($hook == 'theme_test_general_suggestions') {
     array_unshift($suggestions, 'theme_test_general_suggestions__' . 'theme_override');
+    $variables['theme_hook'] = 'test_theme_theme_suggestions_alter';
   }
 }