class ThemeSuggestionsAlterTest

class ThemeSuggestionsAlterTest extends BrowserTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'theme_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        \Drupal::service('theme_installer')->install([
            'test_theme',
        ]);
    }
    
    /**
     * Tests that hooks to provide theme suggestions work.
     */
    public function testTemplateSuggestions() : void {
        $this->drupalGet('theme-test/suggestion-provided');
        $this->assertSession()
            ->pageTextContains('Template for testing suggestions provided by the module declaring the theme hook.');
        // Install test_theme, it contains a template suggested by theme_test.module
        // in theme_test_theme_suggestions_theme_test_suggestion_provided().
        $this->config('system.theme')
            ->set('default', 'test_theme')
            ->save();
        $this->drupalGet('theme-test/suggestion-provided');
        $this->assertSession()
            ->pageTextContains('Template overridden based on suggestion provided by the module declaring the theme hook.');
    }
    
    /**
     * Tests hook_theme_suggestions_alter().
     */
    public function testGeneralSuggestionsAlter() : void {
        $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')
            ->set('default', 'test_theme')
            ->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.
        \Drupal::service('module_installer')->install([
            'theme_suggestions_test',
        ]);
        $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');
    }
    
    /**
     * Tests that theme suggestion alter hooks work for templates.
     */
    public function testTemplateSuggestionsAlter() : void {
        $this->drupalGet('theme-test/suggestion-alter');
        $this->assertSession()
            ->pageTextContains('Original template for testing hook_theme_suggestions_HOOK_alter().');
        // Install test_theme and test that themes can alter template suggestions.
        $this->config('system.theme')
            ->set('default', 'test_theme')
            ->save();
        $this->drupalGet('theme-test/suggestion-alter');
        $this->assertSession()
            ->pageTextContains('Template overridden based on new theme suggestion provided by the test_theme theme via hook_theme_suggestions_HOOK_alter().');
        // Enable the theme_suggestions_test module to test modules implementing
        // suggestions alter hooks.
        \Drupal::service('module_installer')->install([
            'theme_suggestions_test',
        ]);
        $this->resetAll();
        $this->drupalGet('theme-test/suggestion-alter');
        $this->assertSession()
            ->pageTextContains('Template overridden based on new theme suggestion provided by a module via hook_theme_suggestions_HOOK_alter().');
    }
    
    /**
     * Tests that theme suggestion alter hooks work for specific theme calls.
     */
    public function testSpecificSuggestionsAlter() : void {
        // Test that the default template is rendered.
        $this->drupalGet('theme-test/specific-suggestion-alter');
        $this->assertSession()
            ->pageTextContains('Template for testing specific theme calls.');
        $this->config('system.theme')
            ->set('default', 'test_theme')
            ->save();
        // Test a specific theme call similar to '#theme' => 'node__article'.
        $this->drupalGet('theme-test/specific-suggestion-alter');
        $this->assertSession()
            ->pageTextContains('Template matching the specific theme call.');
        $this->assertSession()
            ->pageTextContains('theme_test_specific_suggestions__variant');
        // Ensure that the base hook is used to determine the suggestion alter hook.
        \Drupal::service('module_installer')->install([
            'theme_suggestions_test',
        ]);
        $this->resetAll();
        $this->drupalGet('theme-test/specific-suggestion-alter');
        $this->assertSession()
            ->pageTextContains('Template overridden based on suggestion alter hook determined by the base hook.');
        $raw_content = $this->getSession()
            ->getPage()
            ->getContent();
        // Verify that a specific theme call is added to the suggestions array
        // before the suggestions alter hook.
        $this->assertLessThan(strpos($raw_content, 'theme_test_specific_suggestions__variant__foo'), strpos($raw_content, 'theme_test_specific_suggestions__variant'));
    }
    
    /**
     * Tests execution order of theme suggestion alter hooks.
     *
     * Hook hook_theme_suggestions_alter() should fire before
     * hook_theme_suggestions_HOOK_alter() within an extension (module or theme).
     */
    public function testExecutionOrder() : void {
        // Install our test theme and module.
        $this->config('system.theme')
            ->set('default', 'test_theme')
            ->save();
        \Drupal::service('module_installer')->install([
            'theme_suggestions_test',
        ]);
        $this->resetAll();
        // Send two requests so that we get all the messages we've set via
        // \Drupal\Core\Messenger\MessengerInterface::addStatus().
        $this->drupalGet('theme-test/suggestion-alter');
        // Ensure that the order is first by extension, then for a given extension,
        // the hook-specific one after the generic one.
        $expected_order = [
            'theme_suggestions_test_theme_suggestions_alter() executed.',
            'theme_suggestions_test_theme_suggestions_theme_test_suggestions_alter() executed.',
            'theme_test_theme_suggestions_alter() executed for theme_test_suggestions.',
            'theme_test_theme_suggestions_theme_test_suggestions_alter() executed.',
            'test_theme_theme_suggestions_alter() executed.',
            'test_theme_theme_suggestions_theme_test_suggestions_alter() executed.',
        ];
        $content = preg_replace('/\\s+/', ' ', Xss::filter($this->getSession()
            ->getPage()
            ->getContent(), []));
        $order = 0;
        foreach ($expected_order as $expected_string) {
            $this->assertGreaterThan($order, strpos($content, $expected_string));
            $order = strpos($content, $expected_string);
        }
    }

}