Initial Drupal 11 with DDEV setup

web/core/modules/responsive_image/tests/modules/responsive_image_test_module/config/schema/responsive_image_test_module.schema.yml

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+# Schema for the configuration files of the Responsive image test theme module.
+field.formatter.settings.responsive_image_test:
+  type: mapping
+  label: 'Responsive image list format settings'
+  mapping:
+    responsive_image_style:
+      type: string
+      label: 'Responsive image style'
+    image_link:
+      type: string
+      label: 'Link image to'
+    image_loading:
+      type: mapping
+      label: 'Image loading settings'
+      mapping:
+        attribute:
+          type: string
+          label: 'Loading attribute'

web/core/modules/responsive_image/tests/modules/responsive_image_test_module/responsive_image_test_module.breakpoints.yml

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+responsive_image_test_module.empty:
+  label: empty
+  mediaQuery: ''
+  weight: 0
+  multipliers:
+    - 1x
+    - 1.5x
+    - 2x
+
+responsive_image_test_module.mobile:
+  label: mobile
+  mediaQuery: '(min-width: 0px)'
+  weight: 1
+  multipliers:
+    - 1x
+    - 1.5x
+    - 2x
+responsive_image_test_module.narrow:
+  label: narrow
+  mediaQuery: '(min-width: 560px)'
+  weight: 2
+  multipliers:
+    - 1x
+    - 1.5x
+    - 2x
+responsive_image_test_module.wide:
+  label: wide
+  mediaQuery: '(min-width: 851px)'
+  weight: 3
+  multipliers:
+    - 1x
+    - 1.5x
+    - 2x

web/core/modules/responsive_image/tests/modules/responsive_image_test_module/responsive_image_test_module.info.yml

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+name: 'Responsive image test theme'
+type: module
+description: 'Test theme for responsive image.'
+package: Testing
+version: VERSION

web/core/modules/responsive_image/tests/modules/responsive_image_test_module/src/Plugin/Field/FieldFormatter/ResponsiveImageTestFormatter.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\responsive_image_test_module\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\responsive_image\Plugin\Field\FieldFormatter\ResponsiveImageFormatter;
+use Drupal\Core\Field\FieldItemListInterface;
+
+/**
+ * Plugin to test responsive image formatter.
+ */
+#[FieldFormatter(
+  id: 'responsive_image_test',
+  label: new TranslatableMarkup('Responsive image test'),
+  field_types: [
+    'image',
+  ],
+)]
+class ResponsiveImageTestFormatter extends ResponsiveImageFormatter {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = parent::viewElements($items, $langcode);
+    // Unset #item_attributes to test that the theme function can handle that.
+    foreach ($elements as &$element) {
+      if (isset($element['#item_attributes'])) {
+        unset($element['#item_attributes']);
+      }
+    }
+    return $elements;
+  }
+
+}

web/core/modules/responsive_image/tests/src/Functional/GenericTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional;
+
+use Drupal\Tests\system\Functional\Module\GenericModuleTestBase;
+
+/**
+ * Generic module test for responsive_image.
+ *
+ * @group responsive_image
+ */
+class GenericTest extends GenericModuleTestBase {}

web/core/modules/responsive_image/tests/src/Functional/ResponsiveImageAdminUITest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional;
+
+use Drupal\responsive_image\ResponsiveImageStyleInterface;
+use Drupal\Tests\BrowserTestBase;
+
+// cspell:ignore modulenarrow
+
+/**
+ * Thoroughly test the administrative interface of the Responsive Image module.
+ *
+ * @group responsive_image
+ */
+class ResponsiveImageAdminUITest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'responsive_image',
+    'responsive_image_test_module',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'administer responsive images',
+    ]));
+  }
+
+  /**
+   * Tests responsive image administration functionality.
+   */
+  public function testResponsiveImageAdmin(): void {
+    // We start without any default styles.
+    $this->drupalGet('admin/config/media/responsive-image-style');
+    $this->assertSession()->pageTextContains('There are no responsive image styles yet.');
+
+    // Add a responsive image style.
+    $this->drupalGet('admin/config/media/responsive-image-style/add');
+    // The 'Responsive Image' breakpoint group should be selected by default.
+    $this->assertSession()->fieldValueEquals('breakpoint_group', 'responsive_image');
+
+    // Create a new group.
+    $edit = [
+      'label' => 'Style One',
+      'id' => 'style_one',
+      'breakpoint_group' => 'responsive_image',
+      'fallback_image_style' => 'thumbnail',
+    ];
+    $this->drupalGet('admin/config/media/responsive-image-style/add');
+    $this->submitForm($edit, 'Save');
+
+    // Check if the new group is created.
+    $this->assertSession()->statusCodeEquals(200);
+    $this->drupalGet('admin/config/media/responsive-image-style');
+    $this->assertSession()->pageTextNotContains('There are no responsive image styles yet.');
+    $this->assertSession()->pageTextContains('Style One');
+
+    // Edit the breakpoint_group.
+    $this->drupalGet('admin/config/media/responsive-image-style/style_one');
+    $this->assertSession()->fieldValueEquals('label', 'Style One');
+    $this->assertSession()->fieldValueEquals('breakpoint_group', 'responsive_image');
+    $edit = [
+      'breakpoint_group' => 'responsive_image_test_module',
+    ];
+    $this->submitForm($edit, 'Save');
+
+    // Edit the group.
+    $this->drupalGet('admin/config/media/responsive-image-style/style_one');
+    $this->assertSession()->fieldValueEquals('label', 'Style One');
+    $this->assertSession()->fieldValueEquals('breakpoint_group', 'responsive_image_test_module');
+    $this->assertSession()->fieldValueEquals('fallback_image_style', 'thumbnail');
+
+    $cases = [
+      ['mobile', '1x'],
+      ['mobile', '2x'],
+      ['narrow', '1x'],
+      ['narrow', '2x'],
+      ['wide', '1x'],
+      ['wide', '2x'],
+    ];
+    $image_styles = array_merge(
+      [ResponsiveImageStyleInterface::EMPTY_IMAGE, ResponsiveImageStyleInterface::ORIGINAL_IMAGE],
+      array_keys(image_style_options(FALSE))
+    );
+    foreach ($cases as $case) {
+      // Check if the radio buttons are present.
+      $this->assertSession()->fieldExists('keyed_styles[responsive_image_test_module.' . $case[0] . '][' . $case[1] . '][image_mapping_type]');
+      // Check if the image style dropdowns are present.
+      $this->assertSession()->fieldExists('keyed_styles[responsive_image_test_module.' . $case[0] . '][' . $case[1] . '][image_style]');
+      // Check if the sizes textfields are present.
+      $this->assertSession()->fieldExists('keyed_styles[responsive_image_test_module.' . $case[0] . '][' . $case[1] . '][sizes]');
+
+      foreach ($image_styles as $image_style_name) {
+        // Check if the image styles are available in the dropdowns.
+        $this->assertSession()->optionExists('keyed_styles[responsive_image_test_module.' . $case[0] . '][' . $case[1] . '][image_style]', $image_style_name);
+        // Check if the image styles checkboxes are present.
+        $this->assertSession()->fieldExists('keyed_styles[responsive_image_test_module.' . $case[0] . '][' . $case[1] . '][sizes_image_styles][' . $image_style_name . ']');
+      }
+    }
+
+    // Save styles for 1x variant only.
+    $edit = [
+      'label' => 'Style One',
+      'breakpoint_group' => 'responsive_image_test_module',
+      'fallback_image_style' => 'thumbnail',
+      'keyed_styles[responsive_image_test_module.mobile][1x][image_mapping_type]' => 'image_style',
+      'keyed_styles[responsive_image_test_module.mobile][1x][image_style]' => 'thumbnail',
+      'keyed_styles[responsive_image_test_module.narrow][1x][image_mapping_type]' => 'sizes',
+      // Ensure the Sizes field allows long values.
+      'keyed_styles[responsive_image_test_module.narrow][1x][sizes]' => '(min-resolution: 192dpi) and (min-width: 170px) 386px, (min-width: 170px) 193px, (min-width: 768px) 18vw, (min-width: 480px) 30vw, 48vw',
+      'keyed_styles[responsive_image_test_module.narrow][1x][sizes_image_styles][large]' => 'large',
+      'keyed_styles[responsive_image_test_module.narrow][1x][sizes_image_styles][medium]' => 'medium',
+      'keyed_styles[responsive_image_test_module.wide][1x][image_mapping_type]' => 'image_style',
+      'keyed_styles[responsive_image_test_module.wide][1x][image_style]' => 'large',
+    ];
+    $this->drupalGet('admin/config/media/responsive-image-style/style_one');
+    $this->submitForm($edit, 'Save');
+    $this->drupalGet('admin/config/media/responsive-image-style/style_one');
+
+    // Check the mapping for multipliers 1x and 2x for the mobile breakpoint.
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.mobile][1x][image_style]', 'thumbnail');
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.mobile][1x][image_mapping_type]', 'image_style');
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.mobile][2x][image_mapping_type]', '_none');
+
+    // Check the mapping for multipliers 1x and 2x for the narrow breakpoint.
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.narrow][1x][image_mapping_type]', 'sizes');
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.narrow][1x][sizes]', '(min-resolution: 192dpi) and (min-width: 170px) 386px, (min-width: 170px) 193px, (min-width: 768px) 18vw, (min-width: 480px) 30vw, 48vw');
+    $this->assertSession()->checkboxChecked('edit-keyed-styles-responsive-image-test-modulenarrow-1x-sizes-image-styles-large');
+    $this->assertSession()->checkboxChecked('edit-keyed-styles-responsive-image-test-modulenarrow-1x-sizes-image-styles-medium');
+    $this->assertSession()->checkboxNotChecked('edit-keyed-styles-responsive-image-test-modulenarrow-1x-sizes-image-styles-thumbnail');
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.narrow][2x][image_mapping_type]', '_none');
+
+    // Check the mapping for multipliers 1x and 2x for the wide breakpoint.
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.wide][1x][image_style]', 'large');
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.wide][1x][image_mapping_type]', 'image_style');
+    $this->assertSession()->fieldValueEquals('keyed_styles[responsive_image_test_module.wide][2x][image_mapping_type]', '_none');
+
+    // Delete the style.
+    $this->drupalGet('admin/config/media/responsive-image-style/style_one/delete');
+    $this->submitForm([], 'Delete');
+    $this->drupalGet('admin/config/media/responsive-image-style');
+    $this->assertSession()->pageTextContains('There are no responsive image styles yet.');
+  }
+
+}

web/core/modules/responsive_image/tests/src/Functional/ResponsiveImageFieldDisplayTest.php

@@ -0,0 +1,579 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional;
+
+use Drupal\image\Entity\ImageStyle;
+use Drupal\image\ImageStyleInterface;
+use Drupal\node\Entity\Node;
+use Drupal\file\Entity\File;
+use Drupal\responsive_image\Plugin\Field\FieldFormatter\ResponsiveImageFormatter;
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+use Drupal\responsive_image\ResponsiveImageStyleInterface;
+use Drupal\Tests\image\Functional\ImageFieldTestBase;
+use Drupal\Tests\TestFileCreationTrait;
+use Drupal\user\RoleInterface;
+
+/**
+ * Tests responsive image display formatter.
+ *
+ * @group responsive_image
+ */
+class ResponsiveImageFieldDisplayTest extends ImageFieldTestBase {
+
+  use TestFileCreationTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Responsive image style entity instance we test with.
+   *
+   * @var \Drupal\responsive_image\Entity\ResponsiveImageStyle
+   */
+  protected $responsiveImgStyle;
+
+  /**
+   * The file URL generator.
+   *
+   * @var \Drupal\Core\File\FileUrlGeneratorInterface
+   */
+  protected $fileUrlGenerator;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'field_ui',
+    'responsive_image',
+    'responsive_image_test_module',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->fileUrlGenerator = $this->container->get('file_url_generator');
+
+    // Create user.
+    $this->adminUser = $this->drupalCreateUser([
+      'administer responsive images',
+      'access content',
+      'access administration pages',
+      'administer site configuration',
+      'administer content types',
+      'administer node display',
+      'administer nodes',
+      'create article content',
+      'edit any article content',
+      'delete any article content',
+      'administer image styles',
+    ]);
+    $this->drupalLogin($this->adminUser);
+    // Add responsive image style.
+    $this->responsiveImgStyle = ResponsiveImageStyle::create([
+      'id' => 'style_one',
+      'label' => 'Style One',
+      'breakpoint_group' => 'responsive_image_test_module',
+      'fallback_image_style' => 'large',
+    ]);
+  }
+
+  /**
+   * Tests responsive image formatters on node display for public files.
+   */
+  public function testResponsiveImageFieldFormattersPublic(): void {
+    $this->addTestImageStyleMappings();
+    $this->doTestResponsiveImageFieldFormatters('public');
+  }
+
+  /**
+   * Tests responsive image formatters on node display for private files.
+   */
+  public function testResponsiveImageFieldFormattersPrivate(): void {
+    $this->addTestImageStyleMappings();
+    // Remove access content permission from anonymous users.
+    user_role_change_permissions(RoleInterface::ANONYMOUS_ID, ['access content' => FALSE]);
+    $this->doTestResponsiveImageFieldFormatters('private');
+  }
+
+  /**
+   * Tests responsive image formatters when image style is empty.
+   */
+  public function testResponsiveImageFieldFormattersEmptyStyle(): void {
+    $this->addTestImageStyleMappings(TRUE);
+    $this->doTestResponsiveImageFieldFormatters('public', TRUE);
+  }
+
+  /**
+   * Add image style mappings to the responsive image style entity.
+   *
+   * @param bool $empty_styles
+   *   If true, the image style mappings will get empty image styles.
+   */
+  protected function addTestImageStyleMappings($empty_styles = FALSE): void {
+    if ($empty_styles) {
+      $this->responsiveImgStyle
+        ->addImageStyleMapping('responsive_image_test_module.mobile', '1x', [
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => '',
+        ])
+        ->addImageStyleMapping('responsive_image_test_module.narrow', '1x', [
+          'image_mapping_type' => 'sizes',
+          'image_mapping' => [
+            'sizes' => '(min-width: 700px) 700px, 100vw',
+            'sizes_image_styles' => [],
+          ],
+        ])
+        ->addImageStyleMapping('responsive_image_test_module.wide', '1x', [
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => '',
+        ])
+        ->save();
+    }
+    else {
+      $this->responsiveImgStyle
+        // Test the output of an empty image.
+        ->addImageStyleMapping('responsive_image_test_module.mobile', '1x', [
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => ResponsiveImageStyleInterface::EMPTY_IMAGE,
+        ])
+        // Test the output with a 1.5x multiplier.
+        ->addImageStyleMapping('responsive_image_test_module.mobile', '1.5x', [
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => 'thumbnail',
+        ])
+        // Test the output of the 'sizes' attribute.
+        ->addImageStyleMapping('responsive_image_test_module.narrow', '1x', [
+          'image_mapping_type' => 'sizes',
+          'image_mapping' => [
+            'sizes' => '(min-width: 700px) 700px, 100vw',
+            'sizes_image_styles' => [
+              'large',
+              'medium',
+            ],
+          ],
+        ])
+        // Test the normal output of mapping to an image style.
+        ->addImageStyleMapping('responsive_image_test_module.wide', '1x', [
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => 'large',
+        ])
+        // Test the output of the original image.
+        ->addImageStyleMapping('responsive_image_test_module.wide', '3x', [
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => ResponsiveImageStyleInterface::ORIGINAL_IMAGE,
+        ])
+        ->save();
+    }
+  }
+
+  /**
+   * Tests responsive image formatters on node display.
+   *
+   * If the empty styles param is set, then the function only tests for the
+   * fallback image style (large).
+   *
+   * @param string $scheme
+   *   File scheme to use.
+   * @param bool $empty_styles
+   *   If true, use an empty string for image style names.
+   *   Defaults to false.
+   */
+  protected function doTestResponsiveImageFieldFormatters($scheme, $empty_styles = FALSE): void {
+    /** @var \Drupal\Core\Render\RendererInterface $renderer */
+    $renderer = $this->container->get('renderer');
+    $node_storage = $this->container->get('entity_type.manager')->getStorage('node');
+    $field_name = $this->randomMachineName();
+    $this->createImageField($field_name, 'node', 'article', ['uri_scheme' => $scheme]);
+    // Create a new node with an image attached. Make sure we use a large image
+    // so the scale effects of the image styles always have an effect.
+    $test_image = current($this->getTestFiles('image', 39325));
+
+    // Create alt text for the image.
+    $alt = $this->randomMachineName();
+
+    $nid = $this->uploadNodeImage($test_image, $field_name, 'article', $alt);
+    $node = $node_storage->load($nid);
+
+    // Test that the default formatter is being used.
+    $image_uri = File::load($node->{$field_name}->target_id)->getFileUri();
+    $image = [
+      '#theme' => 'image',
+      '#uri' => $image_uri,
+      '#width' => 360,
+      '#height' => 240,
+      '#alt' => $alt,
+      '#attributes' => ['loading' => 'lazy'],
+    ];
+    $default_output = str_replace("\n", '', (string) $renderer->renderRoot($image));
+    $this->assertSession()->responseContains($default_output);
+
+    // Test field not being configured. This should not cause a fatal error.
+    $display_options = [
+      'type' => 'responsive_image_test',
+      'settings' => ResponsiveImageFormatter::defaultSettings(),
+    ];
+    $display = $this->container->get('entity_type.manager')
+      ->getStorage('entity_view_display')
+      ->load('node.article.default');
+    if (!$display) {
+      $values = [
+        'targetEntityType' => 'node',
+        'bundle' => 'article',
+        'mode' => 'default',
+        'status' => TRUE,
+      ];
+      $display = $this->container->get('entity_type.manager')->getStorage('entity_view_display')->create($values);
+    }
+    $display->setComponent($field_name, $display_options)->save();
+
+    $this->drupalGet('node/' . $nid);
+
+    // Test theme function for responsive image, but using the test formatter.
+    $display_options = [
+      'type' => 'responsive_image_test',
+      'settings' => [
+        'image_link' => 'file',
+        'responsive_image_style' => 'style_one',
+      ],
+    ];
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+    $display = $display_repository->getViewDisplay('node', 'article');
+    $display->setComponent($field_name, $display_options)
+      ->save();
+
+    $this->drupalGet('node/' . $nid);
+
+    // Use the responsive image formatter linked to file formatter.
+    $display_options = [
+      'type' => 'responsive_image',
+      'settings' => [
+        'image_link' => 'file',
+        'responsive_image_style' => 'style_one',
+      ],
+    ];
+    $display = $display_repository->getViewDisplay('node', 'article');
+    $display->setComponent($field_name, $display_options)
+      ->save();
+
+    $this->drupalGet('node/' . $nid);
+    // No image style cache tag should be found.
+    $this->assertSession()->responseHeaderNotContains('X-Drupal-Cache-Tags', 'image_style:');
+
+    $this->assertSession()->responseMatches('/<a(.*?)href="' . preg_quote($this->fileUrlGenerator->generateString($image_uri), '/') . '"(.*?)>\s*<picture/');
+    // Verify that the image can be downloaded.
+    $this->assertEquals(file_get_contents($test_image->uri), $this->drupalGet($this->fileUrlGenerator->generateAbsoluteString($image_uri)), 'File was downloaded successfully.');
+    if ($scheme == 'private') {
+      // Only verify HTTP headers when using private scheme and the headers are
+      // sent by Drupal.
+      $this->assertSession()->responseHeaderEquals('Content-Type', 'image/png');
+      $this->assertSession()->responseHeaderContains('Cache-Control', 'private');
+
+      // Log out and ensure the file cannot be accessed.
+      $this->drupalLogout();
+      $this->drupalGet($this->fileUrlGenerator->generateAbsoluteString($image_uri));
+      $this->assertSession()->statusCodeEquals(403);
+
+      // Log in again.
+      $this->drupalLogin($this->adminUser);
+    }
+
+    // Use the responsive image formatter with a responsive image style.
+    $display_options['settings']['responsive_image_style'] = 'style_one';
+    $display_options['settings']['image_link'] = '';
+    $display->setComponent($field_name, $display_options)
+      ->save();
+
+    // Create a derivative so at least one MIME type will be known.
+    $large_style = ImageStyle::load('large');
+    $large_style->createDerivative($image_uri, $large_style->buildUri($image_uri));
+
+    // Output should contain all image styles and all breakpoints.
+    $this->drupalGet('node/' . $nid);
+    if (!$empty_styles) {
+      $this->assertSession()->responseContains('/styles/medium/');
+      // Assert the empty image is present.
+      $this->assertSession()->responseContains('data:image/gif;base64,R0lGODlhAQABAIABAP///wAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==');
+      $thumbnail_style = ImageStyle::load('thumbnail');
+      // Assert the output of the 'srcset' attribute (small multipliers first).
+      $this->assertSession()->responseContains('data:image/gif;base64,R0lGODlhAQABAIABAP///wAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw== 1x, ' . $this->fileUrlGenerator->transformRelative($thumbnail_style->buildUrl($image_uri)) . ' 1.5x');
+      $this->assertSession()->responseContains('/styles/medium/');
+      // Assert the output of the original image.
+      $this->assertSession()->responseContains($this->fileUrlGenerator->generateString($image_uri) . ' 3x');
+      // Assert the output of the breakpoints.
+      $this->assertSession()->responseContains('media="(min-width: 0px)"');
+      $this->assertSession()->responseContains('media="(min-width: 560px)"');
+      // Assert the output of the 'sizes' attribute.
+      $this->assertSession()->responseContains('sizes="(min-width: 700px) 700px, 100vw"');
+      $this->assertSession()->responseMatches('/media="\(min-width: 560px\)".+?sizes="\(min-width: 700px\) 700px, 100vw"/');
+      // Assert the output of the 'srcset' attribute (small images first).
+      $medium_style = ImageStyle::load('medium');
+      $this->assertSession()->responseContains($this->fileUrlGenerator->transformRelative($medium_style->buildUrl($image_uri)) . ' 220w, ' . $this->fileUrlGenerator->transformRelative($large_style->buildUrl($image_uri)) . ' 360w');
+      $this->assertSession()->responseContains('media="(min-width: 851px)"');
+      // Assert the output of the 'width' attribute.
+      $this->assertSession()->responseContains('width="360"');
+      // Assert the output of the 'height' attribute.
+      $this->assertSession()->responseContains('height="240"');
+      $this->assertSession()->responseContains('loading="lazy"');
+    }
+    $this->assertSession()->responseContains('/styles/large/');
+    $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', 'config:responsive_image.styles.style_one');
+    if (!$empty_styles) {
+      $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', 'config:image.style.medium');
+      $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', 'config:image.style.thumbnail');
+      $this->assertSession()->responseContains('type="image/avif"');
+    }
+    $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', 'config:image.style.large');
+
+    // Test the fallback image style. Copy the source image:
+    $fallback_image = $image;
+    // Set the fallback image style uri:
+    $fallback_image['#uri'] = $this->fileUrlGenerator->transformRelative($large_style->buildUrl($image_uri));
+    // The image.html.twig template has a newline after the <img> tag but
+    // responsive-image.html.twig doesn't have one after the fallback image, so
+    // we remove it here.
+    $default_output = trim((string) $renderer->renderRoot($fallback_image));
+    $this->assertSession()->responseContains($default_output);
+
+    if ($scheme == 'private') {
+      // Log out and ensure the file cannot be accessed.
+      $this->drupalLogout();
+      $this->drupalGet($large_style->buildUrl($image_uri));
+      $this->assertSession()->statusCodeEquals(403);
+      $this->assertSession()->responseHeaderNotMatches('X-Drupal-Cache-Tags', '/ image_style\:/');
+    }
+  }
+
+  /**
+   * Tests responsive image formatters on node display linked to the file.
+   */
+  public function testResponsiveImageFieldFormattersLinkToFile(): void {
+    $this->addTestImageStyleMappings();
+    $this->assertResponsiveImageFieldFormattersLink('file');
+  }
+
+  /**
+   * Tests responsive image formatters on node display linked to the node.
+   */
+  public function testResponsiveImageFieldFormattersLinkToNode(): void {
+    $this->addTestImageStyleMappings();
+    $this->assertResponsiveImageFieldFormattersLink('content');
+  }
+
+  /**
+   * Tests responsive image formatter on node display with an empty media query.
+   */
+  public function testResponsiveImageFieldFormattersEmptyMediaQuery(): void {
+    $this->responsiveImgStyle
+      // Test the output of an empty media query.
+      ->addImageStyleMapping('responsive_image_test_module.empty', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => ResponsiveImageStyleInterface::EMPTY_IMAGE,
+      ])
+      // Test the output with a 1.5x multiplier.
+      ->addImageStyleMapping('responsive_image_test_module.mobile', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'thumbnail',
+      ])
+      ->save();
+    $node_storage = $this->container->get('entity_type.manager')->getStorage('node');
+    $field_name = $this->randomMachineName();
+    $this->createImageField($field_name, 'node', 'article', ['uri_scheme' => 'public']);
+    // Create a new node with an image attached.
+    $test_image = current($this->getTestFiles('image'));
+    $nid = $this->uploadNodeImage($test_image, $field_name, 'article', $this->randomMachineName());
+
+    // Use the responsive image formatter linked to file formatter.
+    $display_options = [
+      'type' => 'responsive_image',
+      'settings' => [
+        'image_link' => '',
+        'responsive_image_style' => 'style_one',
+      ],
+    ];
+    $display = \Drupal::service('entity_display.repository')
+      ->getViewDisplay('node', 'article');
+    $display->setComponent($field_name, $display_options)
+      ->save();
+
+    // View the node.
+    $this->drupalGet('node/' . $nid);
+
+    // Assert an empty media attribute is not output.
+    $this->assertSession()->responseNotMatches('@srcset="data:image/gif;base64,R0lGODlhAQABAIABAP///wAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw== 1x".+?media=".+?/><source@');
+
+    // Assert the media attribute is present if it has a value.
+    $thumbnail_style = ImageStyle::load('thumbnail');
+    $node = $node_storage->load($nid);
+    $image_uri = File::load($node->{$field_name}->target_id)->getFileUri();
+    $this->assertSession()->responseMatches('/srcset="' . preg_quote($this->fileUrlGenerator->transformRelative($thumbnail_style->buildUrl($image_uri)), '/') . ' 1x".+?media="\(min-width: 0px\)"/');
+  }
+
+  /**
+   * Tests responsive image formatter on node display with one and two sources.
+   */
+  public function testResponsiveImageFieldFormattersMultipleSources(): void {
+    // Setup known image style sizes so the test can assert on known sizes.
+    $large_style = ImageStyle::load('large');
+    assert($large_style instanceof ImageStyleInterface);
+    $large_style->addImageEffect([
+      'id' => 'image_resize',
+      'weight' => 0,
+      'data' => [
+        'width' => '480',
+        'height' => '480',
+      ],
+    ]);
+    $large_style->save();
+    $medium_style = ImageStyle::load('medium');
+    assert($medium_style instanceof ImageStyleInterface);
+    $medium_style->addImageEffect([
+      'id' => 'image_resize',
+      'weight' => 0,
+      'data' => [
+        'width' => '220',
+        'height' => '220',
+      ],
+    ]);
+    $medium_style->save();
+
+    $this->responsiveImgStyle
+      // Test the output of an empty media query.
+      ->addImageStyleMapping('responsive_image_test_module.empty', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => $medium_style->id(),
+      ])
+      ->addImageStyleMapping('responsive_image_test_module.empty', '1.5x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => $large_style->id(),
+      ])
+      ->addImageStyleMapping('responsive_image_test_module.empty', '2x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => $large_style->id(),
+      ])
+      ->save();
+    $node_storage = $this->container->get('entity_type.manager')->getStorage('node');
+    $field_name = $this->randomMachineName();
+    $this->createImageField($field_name, 'node', 'article', ['uri_scheme' => 'public']);
+    // Create a new node with an image attached.
+    $test_image = current($this->getTestFiles('image'));
+    $nid = $this->uploadNodeImage($test_image, $field_name, 'article', $this->randomMachineName());
+
+    // Use the responsive image formatter linked to file formatter.
+    $display_options = [
+      'type' => 'responsive_image',
+      'settings' => [
+        'image_link' => '',
+        'responsive_image_style' => 'style_one',
+        'image_loading' => [
+          // Test the image loading default option can be overridden.
+          'attribute' => 'eager',
+        ],
+      ],
+    ];
+    $display = \Drupal::service('entity_display.repository')
+      ->getViewDisplay('node', 'article');
+    $display->setComponent($field_name, $display_options)
+      ->save();
+
+    // View the node.
+    $this->drupalGet('node/' . $nid);
+
+    // Assert the img tag has medium and large images and fallback dimensions
+    // from the large image style are used.
+    $node = $node_storage->load($nid);
+    $image_uri = File::load($node->{$field_name}->target_id)->getFileUri();
+    $medium_transform_url = $this->fileUrlGenerator->transformRelative($medium_style->buildUrl($image_uri));
+    $large_transform_url = $this->fileUrlGenerator->transformRelative($large_style->buildUrl($image_uri));
+    $this->assertSession()->responseMatches('/<img loading="eager" srcset="' . \preg_quote($medium_transform_url, '/') . ' 1x, ' . \preg_quote($large_transform_url, '/') . ' 1.5x, ' . \preg_quote($large_transform_url, '/') . ' 2x" width="480" height="480" src="' . \preg_quote($large_transform_url, '/') . '" alt="\w+" \/>/');
+
+    $this->responsiveImgStyle
+      // Test the output of an empty media query.
+      ->addImageStyleMapping('responsive_image_test_module.wide', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => $large_style->id(),
+      ])
+      ->save();
+
+    // Assert the picture tag has source tags that include dimensions.
+    $this->drupalGet('node/' . $nid);
+    $this->assertSession()->responseMatches('/<picture>\s+<source srcset="' . \preg_quote($large_transform_url, '/') . ' 1x" media="\(min-width: 851px\)" type="image\/avif" width="480" height="480"\/>\s+<source srcset="' . \preg_quote($medium_transform_url, '/') . ' 1x, ' . \preg_quote($large_transform_url, '/') . ' 1.5x, ' . \preg_quote($large_transform_url, '/') . ' 2x" type="image\/avif" width="220" height="220"\/>\s+<img loading="eager" width="480" height="480" src="' . \preg_quote($large_transform_url, '/') . '" alt="\w+" \/>\s+<\/picture>/');
+  }
+
+  /**
+   * Tests responsive image formatters linked to the file or node.
+   *
+   * @param string $link_type
+   *   The link type to test. Either 'file' or 'content'.
+   */
+  private function assertResponsiveImageFieldFormattersLink(string $link_type): void {
+    $field_name = $this->randomMachineName();
+    $field_settings = ['alt_field_required' => 0];
+    $this->createImageField($field_name, 'node', 'article', ['uri_scheme' => 'public'], $field_settings);
+    // Create a new node with an image attached.
+    $test_image = current($this->getTestFiles('image'));
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Test the image linked to file formatter.
+    $display_options = [
+      'type' => 'responsive_image',
+      'settings' => [
+        'image_link' => $link_type,
+        'responsive_image_style' => 'style_one',
+      ],
+    ];
+    $display_repository->getViewDisplay('node', 'article')
+      ->setComponent($field_name, $display_options)
+      ->save();
+    // Ensure that preview works.
+    $this->previewNodeImage($test_image, $field_name, 'article');
+
+    // Look for a picture tag in the preview output
+    $this->assertSession()->responseMatches('/picture/');
+
+    $nid = $this->uploadNodeImage($test_image, $field_name, 'article');
+    $this->container->get('entity_type.manager')->getStorage('node')->resetCache([$nid]);
+    $node = Node::load($nid);
+
+    // Use the responsive image formatter linked to file formatter.
+    $display_options = [
+      'type' => 'responsive_image',
+      'settings' => [
+        'image_link' => $link_type,
+        'responsive_image_style' => 'style_one',
+      ],
+    ];
+    $display_repository->getViewDisplay('node', 'article')
+      ->setComponent($field_name, $display_options)
+      ->save();
+
+    // Create a derivative so at least one MIME type will be known.
+    $large_style = ImageStyle::load('large');
+    $image_uri = File::load($node->{$field_name}->target_id)->getFileUri();
+    $large_style->createDerivative($image_uri, $large_style->buildUri($image_uri));
+
+    // Output should contain all image styles and all breakpoints.
+    $this->drupalGet('node/' . $nid);
+    switch ($link_type) {
+      case 'file':
+        // Make sure the link to the file is present.
+        $this->assertSession()->responseMatches('/<a(.*?)href="' . preg_quote($this->fileUrlGenerator->generateString($image_uri), '/') . '"(.*?)>\s*<picture/');
+        break;
+
+      case 'content':
+        // Make sure the link to the node is present.
+        $this->assertSession()->responseMatches('/<a(.*?)href="' . preg_quote($node->toUrl()->toString(), '/') . '"(.*?)>\s*<picture/');
+        break;
+    }
+  }
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonAnonTest.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class ResponsiveImageStyleJsonAnonTest extends ResponsiveImageStyleResourceTestBase {
+
+  use AnonResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonBasicAuthTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class ResponsiveImageStyleJsonBasicAuthTest extends ResponsiveImageStyleResourceTestBase {
+
+  use BasicAuthResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['basic_auth'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'basic_auth';
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonCookieTest.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\CookieResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class ResponsiveImageStyleJsonCookieTest extends ResponsiveImageStyleResourceTestBase {
+
+  use CookieResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'cookie';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleResourceTestBase.php

@@ -0,0 +1,132 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+use Drupal\Tests\rest\Functional\EntityResource\ConfigEntityResourceTestBase;
+
+/**
+ * Resource test base for ResponsiveImageStyle entity.
+ */
+abstract class ResponsiveImageStyleResourceTestBase extends ConfigEntityResourceTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['responsive_image'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $entityTypeId = 'responsive_image_style';
+
+  /**
+   * The ResponsiveImageStyle entity.
+   *
+   * @var \Drupal\responsive_image\ResponsiveImageStyleInterface
+   */
+  protected $entity;
+
+  /**
+   * The effect UUID.
+   *
+   * @var string
+   */
+  protected $effectUuid;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUpAuthorization($method) {
+    $this->grantPermissionsToTestedRole(['administer responsive images']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function createEntity() {
+    // Create a "Camelids" responsive image style.
+    $camelids = ResponsiveImageStyle::create([
+      'id' => 'camelids',
+      'label' => 'Camelids',
+    ]);
+    $camelids->setBreakpointGroup('test_group');
+    $camelids->setFallbackImageStyle('fallback');
+    $camelids->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'small',
+    ]);
+    $camelids->addImageStyleMapping('test_breakpoint', '2x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'medium' => 'medium',
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $camelids->save();
+
+    return $camelids;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedNormalizedEntity() {
+    return [
+      'breakpoint_group' => 'test_group',
+      'dependencies' => [
+        'config' => [
+          'image.style.large',
+          'image.style.medium',
+        ],
+      ],
+      'fallback_image_style' => 'fallback',
+      'id' => 'camelids',
+      'image_style_mappings' => [
+        0 => [
+          'breakpoint_id' => 'test_breakpoint',
+          'image_mapping' => 'small',
+          'image_mapping_type' => 'image_style',
+          'multiplier' => '1x',
+        ],
+        1 => [
+          'breakpoint_id' => 'test_breakpoint',
+          'image_mapping' => [
+            'sizes' => '(min-width:700px) 700px, 100vw',
+            'sizes_image_styles' => [
+              'large' => 'large',
+              'medium' => 'medium',
+            ],
+          ],
+          'image_mapping_type' => 'sizes',
+          'multiplier' => '2x',
+        ],
+      ],
+      'label' => 'Camelids',
+      'langcode' => 'en',
+      'status' => TRUE,
+      'uuid' => $this->entity->uuid(),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getNormalizedPostEntity() {
+    // @todo Update in https://www.drupal.org/node/2300677.
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedUnauthorizedAccessMessage($method) {
+    return "The 'administer responsive images' permission is required.";
+  }
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlAnonTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class ResponsiveImageStyleXmlAnonTest extends ResponsiveImageStyleResourceTestBase {
+
+  use AnonResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlBasicAuthTest.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class ResponsiveImageStyleXmlBasicAuthTest extends ResponsiveImageStyleResourceTestBase {
+
+  use BasicAuthResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['basic_auth'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'basic_auth';
+
+}

web/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlCookieTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\CookieResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class ResponsiveImageStyleXmlCookieTest extends ResponsiveImageStyleResourceTestBase {
+
+  use CookieResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'cookie';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

web/core/modules/responsive_image/tests/src/Functional/ViewsIntegrationTest.php

@@ -0,0 +1,116 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Functional;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+use Drupal\Tests\views\Functional\ViewTestBase;
+
+/**
+ * Tests the integration of responsive image with Views.
+ *
+ * @group responsive_image
+ */
+class ViewsIntegrationTest extends ViewTestBase {
+
+  /**
+   * The responsive image style ID to use.
+   */
+  const RESPONSIVE_IMAGE_STYLE_ID = 'responsive_image_style_id';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'views',
+    'views_ui',
+    'responsive_image',
+    'field',
+    'image',
+    'file',
+    'entity_test',
+    'breakpoint',
+    'responsive_image_test_module',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The test views to enable.
+   *
+   * @var string[]
+   */
+  public static $testViews = ['entity_test_row'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp($import_test_views = TRUE, $modules = ['views_test_config']): void {
+    parent::setUp($import_test_views, $modules);
+
+    $this->enableViewsTestModule();
+
+    // Create a responsive image style.
+    $responsive_image_style = ResponsiveImageStyle::create([
+      'id' => self::RESPONSIVE_IMAGE_STYLE_ID,
+      'label' => 'Foo',
+      'breakpoint_group' => 'responsive_image_test_module',
+    ]);
+    // Create an image field to be used with a responsive image formatter.
+    FieldStorageConfig::create([
+      'type' => 'image',
+      'entity_type' => 'entity_test',
+      'field_name' => 'bar',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'field_name' => 'bar',
+    ])->save();
+
+    $responsive_image_style
+      ->addImageStyleMapping('responsive_image_test_module.mobile', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'thumbnail',
+      ])
+      ->addImageStyleMapping('responsive_image_test_module.narrow', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'medium',
+      ])
+      // Test the normal output of mapping to an image style.
+      ->addImageStyleMapping('responsive_image_test_module.wide', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'large',
+      ])
+      ->save();
+
+    $admin_user = $this->drupalCreateUser(['administer views']);
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests integration with Views.
+   */
+  public function testViewsAddResponsiveImageField(): void {
+    // Add the image field to the View.
+    $this->drupalGet('admin/structure/views/nojs/add-handler/entity_test_row/default/field');
+    $this->drupalGet('admin/structure/views/nojs/add-handler/entity_test_row/default/field');
+    $this->submitForm(['name[entity_test__bar.bar]' => TRUE], 'Add and configure field');
+    // Set the formatter to 'Responsive image'.
+    $this->submitForm(['options[type]' => 'responsive_image'], 'Apply');
+    $this->assertSession()
+      ->responseContains('Responsive image style field is required.');
+    $this->submitForm(['options[settings][responsive_image_style]' => self::RESPONSIVE_IMAGE_STYLE_ID], 'Apply');
+    $this->drupalGet('admin/structure/views/nojs/handler/entity_test_row/default/field/bar');
+    // Make sure the selected value is set.
+    $this->assertSession()
+      ->fieldValueEquals('options[settings][responsive_image_style]', self::RESPONSIVE_IMAGE_STYLE_ID);
+  }
+
+}

web/core/modules/responsive_image/tests/src/FunctionalJavascript/ResponsiveImageFieldUiTest.php

@@ -0,0 +1,159 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\FunctionalJavascript;
+
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+use Drupal\Tests\field_ui\Traits\FieldUiJSTestTrait;
+
+/**
+ * Tests the responsive image field UI.
+ *
+ * @group responsive_image
+ */
+class ResponsiveImageFieldUiTest extends WebDriverTestBase {
+
+  use FieldUiJSTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'node',
+    'field_ui',
+    'image',
+    'responsive_image',
+    'responsive_image_test_module',
+    'block',
+  ];
+
+  /**
+   * The content type id.
+   *
+   * @var string
+   */
+  protected string $type;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+    $this->drupalPlaceBlock('local_actions_block');
+    // Create a test user.
+    $admin_user = $this->drupalCreateUser([
+      'access content',
+      'administer content types',
+      'administer node fields',
+      'administer node form display',
+      'administer node display',
+      'bypass node access',
+    ]);
+    $this->drupalLogin($admin_user);
+
+    // Create content type, with underscores.
+    $type_name = $this->randomMachineName(8) . '_test';
+    $type = $this->drupalCreateContentType([
+      'name' => $type_name,
+      'type' => $type_name,
+    ]);
+    $this->type = $type->id();
+  }
+
+  /**
+   * Tests formatter settings.
+   */
+  public function testResponsiveImageFormatterUi(): void {
+    $manage = 'admin/structure/types/manage/' . $this->type;
+    $manage_display = $manage . '/display';
+    /** @var \Drupal\FunctionalJavascriptTests\JSWebAssert $assert_session */
+    $assert_session = $this->assertSession();
+
+    $this->fieldUIAddNewFieldJS('admin/structure/types/manage/' . $this->type, 'image', 'Image', 'image');
+
+    // Display the "Manage display" page.
+    $this->drupalGet($manage_display);
+
+    // Change the formatter and check that the summary is updated.
+    $page = $this->getSession()->getPage();
+
+    $field_image_type = $page->findField('fields[field_image][type]');
+    $field_image_type->setValue('responsive_image');
+
+    $summary_text = $assert_session->waitForElement('xpath', $this->cssSelectToXpath('#field-image .ajax-new-content .field-plugin-summary'));
+    $this->assertEquals('Select a responsive image style. Loading attribute: lazy', $summary_text->getText());
+
+    $page->pressButton('Save');
+    $assert_session->responseContains("Select a responsive image style.");
+
+    // Create responsive image styles.
+    $responsive_image_style = ResponsiveImageStyle::create([
+      'id' => 'style_one',
+      'label' => 'Style One',
+      'breakpoint_group' => 'responsive_image_test_module',
+      'fallback_image_style' => 'thumbnail',
+    ]);
+    $responsive_image_style
+      ->addImageStyleMapping('responsive_image_test_module.mobile', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'thumbnail',
+      ])
+      ->addImageStyleMapping('responsive_image_test_module.narrow', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'medium',
+      ])
+      // Test the normal output of mapping to an image style.
+      ->addImageStyleMapping('responsive_image_test_module.wide', '1x', [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'large',
+      ])
+      ->save();
+    \Drupal::service('entity_field.manager')->clearCachedFieldDefinitions();
+    // Refresh the page.
+    $this->drupalGet($manage_display);
+    $assert_session->responseContains("Select a responsive image style.");
+
+    // Click on the formatter settings button to open the formatter settings
+    // form.
+    $field_image_type = $page->findField('fields[field_image][type]');
+    $field_image_type->setValue('responsive_image');
+
+    $page->find('css', '#edit-fields-field-image-settings-edit')->click();
+    $assert_session->waitForField('fields[field_image][settings_edit_form][settings][responsive_image_style]');
+
+    // Assert that the correct fields are present.
+    $fieldnames = [
+      'fields[field_image][settings_edit_form][settings][responsive_image_style]',
+      'fields[field_image][settings_edit_form][settings][image_link]',
+    ];
+    foreach ($fieldnames as $fieldname) {
+      $assert_session->fieldExists($fieldname);
+    }
+    $page->findField('fields[field_image][settings_edit_form][settings][responsive_image_style]')->setValue('style_one');
+    $page->findField('fields[field_image][settings_edit_form][settings][image_link]')->setValue('content');
+    // Save the form to save the settings.
+    $page->pressButton('Save');
+
+    $this->assertTrue($assert_session->waitForText('Responsive image style: Style One'));
+    $this->assertTrue($assert_session->waitForText('Linked to content'));
+
+    $page->find('css', '#edit-fields-field-image-settings-edit')->click();
+    $assert_session->waitForField('fields[field_image][settings_edit_form][settings][responsive_image_style]');
+    $page->findField('fields[field_image][settings_edit_form][settings][image_link]')->setValue('file');
+
+    // Save the form to save the settings.
+    $page->pressButton('Save');
+
+    $this->assertTrue($assert_session->waitForText('Responsive image style: Style One'));
+    $this->assertTrue($assert_session->waitForText('Linked to file'));
+  }
+
+}

web/core/modules/responsive_image/tests/src/Kernel/Migrate/d7/MigrateResponsiveImageStylesTest.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Kernel\Migrate\d7;
+
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+use Drupal\Tests\migrate_drupal\Kernel\d7\MigrateDrupal7TestBase;
+
+/**
+ * Tests migration of responsive image styles.
+ *
+ * @group responsive_image
+ */
+class MigrateResponsiveImageStylesTest extends MigrateDrupal7TestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['responsive_image', 'breakpoint', 'image'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    // Ensure the 'picture' module is enabled in the source.
+    $this->sourceDatabase->update('system')
+      ->condition('name', 'picture')
+      ->fields(['status' => 1])
+      ->execute();
+    $this->executeMigrations(['d7_image_styles', 'd7_responsive_image_styles']);
+  }
+
+  /**
+   * Tests the Drupal 7 to Drupal 8 responsive image styles migration.
+   */
+  public function testResponsiveImageStyles(): void {
+    $expected_image_style_mappings = [
+      [
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'custom_image_style_1',
+        'breakpoint_id' => 'responsive_image.computer',
+        'multiplier' => 'multiplier_1',
+      ],
+      [
+        'image_mapping_type' => 'sizes',
+        'image_mapping' => [
+          'sizes' => '2',
+          'sizes_image_styles' => [
+            'custom_image_style_1',
+            'custom_image_style_2',
+          ],
+        ],
+        'breakpoint_id' => 'responsive_image.computer',
+        'multiplier' => 'multiplier_2',
+      ],
+      [
+        'image_mapping_type' => 'sizes',
+        'image_mapping' => [
+          'sizes' => '2',
+          'sizes_image_styles' => [
+            'custom_image_style_1',
+            'custom_image_style_2',
+          ],
+        ],
+        'breakpoint_id' => 'responsive_image.computertwo',
+        'multiplier' => 'multiplier_2',
+      ],
+    ];
+    $this->assertSame($expected_image_style_mappings, ResponsiveImageStyle::load('narrow')
+      ->getImageStyleMappings());
+  }
+
+}

web/core/modules/responsive_image/tests/src/Kernel/Plugin/migrate/source/d7/ResponsiveImageStylesTest.php

@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Kernel\Plugin\migrate\source\d7;
+
+use Drupal\Tests\migrate\Kernel\MigrateSqlSourceTestBase;
+
+/**
+ * Tests D7 responsive image styles source plugin.
+ *
+ * @covers \Drupal\responsive_image\Plugin\migrate\source\d7\ResponsiveImageStyles
+ * @group image
+ */
+class ResponsiveImageStylesTest extends MigrateSqlSourceTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'migrate_drupal',
+    'responsive_image',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function providerSource() {
+    $tests = [];
+
+    // The source data.
+    $tests[0]['source_data']['picture_mapping'] = [
+      [
+        'label' => 'Narrow',
+        'machine_name' => 'narrow',
+        'breakpoint_group' => 'responsive_image',
+        'mapping' => 'a:2:{s:38:"breakpoints.theme.my_theme_id.computer";a:3:{s:12:"multiplier_1";a:2:{s:12:"mapping_type";s:11:"image_style";s:11:"image_style";s:20:"custom_image_style_1";}s:12:"multiplier_2";a:3:{s:12:"mapping_type";s:5:"sizes";s:5:"sizes";i:2;s:18:"sizes_image_styles";a:2:{i:0;s:20:"custom_image_style_1";i:1;s:20:"custom_image_style_2";}}s:12:"multiplier_3";a:1:{s:12:"mapping_type";s:5:"_none";}}s:42:"breakpoints.theme.my_theme_id.computer_two";a:1:{s:12:"multiplier_2";a:3:{s:12:"mapping_type";s:5:"sizes";s:5:"sizes";i:2;s:18:"sizes_image_styles";a:2:{i:0;s:20:"custom_image_style_1";i:1;s:20:"custom_image_style_2";}}}}',
+      ],
+    ];
+
+    // The expected results.
+    $tests[0]['expected_data'] = [
+      [
+        'label' => 'Narrow',
+        'machine_name' => 'narrow',
+        'breakpoint_group' => 'responsive_image',
+        'mapping' => [
+          'breakpoints.theme.my_theme_id.computer' =>
+            [
+              'multiplier_1' =>
+                [
+                  'mapping_type' => 'image_style',
+                  'image_style' => 'custom_image_style_1',
+                ],
+              'multiplier_2' =>
+                [
+                  'mapping_type' => 'sizes',
+                  'sizes' => 2,
+                  'sizes_image_styles' =>
+                    [
+                      0 => 'custom_image_style_1',
+                      1 => 'custom_image_style_2',
+                    ],
+                ],
+              'multiplier_3' =>
+                [
+                  'mapping_type' => '_none',
+                ],
+            ],
+          'breakpoints.theme.my_theme_id.computer_two' =>
+            [
+              'multiplier_2' =>
+                [
+                  'mapping_type' => 'sizes',
+                  'sizes' => 2,
+                  'sizes_image_styles' =>
+                    [
+                      0 => 'custom_image_style_1',
+                      1 => 'custom_image_style_2',
+                    ],
+                ],
+            ],
+        ],
+      ],
+    ];
+
+    return $tests;
+  }
+
+}

web/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageIntegrationTest.php

@@ -0,0 +1,91 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Kernel;
+
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+
+/**
+ * Tests the integration of responsive image with other components.
+ *
+ * @group responsive_image
+ */
+class ResponsiveImageIntegrationTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'responsive_image',
+    'field',
+    'image',
+    'file',
+    'entity_test',
+    'breakpoint',
+    'responsive_image_test_module',
+    'user',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->installEntitySchema('entity_test');
+  }
+
+  /**
+   * Tests integration with entity view display.
+   */
+  public function testEntityViewDisplayDependency(): void {
+    // Create a responsive image style.
+    ResponsiveImageStyle::create([
+      'id' => 'foo',
+      'label' => 'Foo',
+      'breakpoint_group' => 'responsive_image_test_module',
+    ])->save();
+    // Create an image field to be used with a responsive image formatter.
+    FieldStorageConfig::create([
+      'type' => 'image',
+      'entity_type' => 'entity_test',
+      'field_name' => 'bar',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'field_name' => 'bar',
+    ])->save();
+    /** @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display */
+    $display = EntityViewDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'default',
+    ]);
+    $display->setComponent('bar', [
+      'type' => 'responsive_image',
+      'label' => 'hidden',
+      'settings' => ['responsive_image_style' => 'foo', 'image_link' => ''],
+      'third_party_settings' => [],
+    ])->save();
+
+    // Check that the 'foo' field is on the display.
+    $this->assertNotNull($display = EntityViewDisplay::load('entity_test.entity_test.default'));
+    $this->assertNotEmpty($display->getComponent('bar'));
+    $this->assertArrayNotHasKey('bar', $display->get('hidden'));
+
+    // Delete the responsive image style.
+    ResponsiveImageStyle::load('foo')->delete();
+
+    // Check that the view display was not deleted.
+    $this->assertNotNull($display = EntityViewDisplay::load('entity_test.entity_test.default'));
+    // Check that the 'foo' field was disabled.
+    $this->assertNull($display->getComponent('bar'));
+    $this->assertArrayHasKey('bar', $display->get('hidden'));
+  }
+
+}

web/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageStyleValidationTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Kernel;
+
+use Drupal\KernelTests\Core\Config\ConfigEntityValidationTestBase;
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+
+/**
+ * Tests validation of responsive_image_style entities.
+ *
+ * @group responsive_image
+ */
+class ResponsiveImageStyleValidationTest extends ConfigEntityValidationTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['breakpoint', 'image', 'responsive_image'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->entity = ResponsiveImageStyle::create([
+      'id' => 'test',
+      'label' => 'Test',
+    ]);
+    $this->entity->save();
+  }
+
+}

web/core/modules/responsive_image/tests/src/Unit/ResponsiveImageStyleConfigEntityUnitTest.php

@@ -0,0 +1,407 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\responsive_image\Unit;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\EntityTypeRepositoryInterface;
+use Drupal\responsive_image\Entity\ResponsiveImageStyle;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\responsive_image\Entity\ResponsiveImageStyle
+ * @group block
+ */
+class ResponsiveImageStyleConfigEntityUnitTest extends UnitTestCase {
+
+  /**
+   * The entity type used for testing.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeInterface|\PHPUnit\Framework\MockObject\MockObject
+   */
+  protected $entityType;
+
+  /**
+   * The entity type manager used for testing.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface|\PHPUnit\Framework\MockObject\MockObject
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The breakpoint manager used for testing.
+   *
+   * @var \Drupal\breakpoint\BreakpointManagerInterface|\PHPUnit\Framework\MockObject\MockObject
+   */
+  protected $breakpointManager;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->entityType = $this->createMock('\Drupal\Core\Entity\EntityTypeInterface');
+    $this->entityType->expects($this->any())
+      ->method('getProvider')
+      ->willReturn('responsive_image');
+
+    $this->entityTypeManager = $this->createMock(EntityTypeManagerInterface::class);
+    $this->entityTypeManager->expects($this->any())
+      ->method('getDefinition')
+      ->with('responsive_image_style')
+      ->willReturn($this->entityType);
+
+    $this->breakpointManager = $this->createMock('\Drupal\breakpoint\BreakpointManagerInterface');
+
+    $container = new ContainerBuilder();
+    $container->set('entity_type.manager', $this->entityTypeManager);
+    $container->set('breakpoint.manager', $this->breakpointManager);
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * @covers ::calculateDependencies
+   */
+  public function testCalculateDependencies(): void {
+    // Set up image style loading mock.
+    $styles = [];
+    foreach (['fallback', 'small', 'medium', 'large'] as $style) {
+      $mock = $this->createMock('Drupal\Core\Config\Entity\ConfigEntityInterface');
+      $mock->expects($this->any())
+        ->method('getConfigDependencyName')
+        ->willReturn('image.style.' . $style);
+      $styles[$style] = $mock;
+    }
+    $storage = $this->createMock('\Drupal\Core\Config\Entity\ConfigEntityStorageInterface');
+    $storage->expects($this->any())
+      ->method('loadMultiple')
+      ->with(array_keys($styles))
+      ->willReturn($styles);
+
+    $this->entityTypeManager->expects($this->any())
+      ->method('getStorage')
+      ->with('image_style')
+      ->willReturn($storage);
+
+    $entity_type_repository = $this->createMock(EntityTypeRepositoryInterface::class);
+    $entity_type_repository->expects($this->any())
+      ->method('getEntityTypeFromClass')
+      ->with('Drupal\image\Entity\ImageStyle')
+      ->willReturn('image_style');
+
+    $entity = new ResponsiveImageStyle(['breakpoint_group' => 'test_group']);
+    $entity->setBreakpointGroup('test_group');
+    $entity->setFallbackImageStyle('fallback');
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'small',
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint', '2x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'medium' => 'medium',
+          'large' => 'large',
+        ],
+      ],
+    ]);
+
+    $this->breakpointManager->expects($this->any())
+      ->method('getGroupProviders')
+      ->with('test_group')
+      ->willReturn(['olivero' => 'theme', 'toolbar' => 'module']);
+
+    \Drupal::getContainer()->set('entity_type.repository', $entity_type_repository);
+
+    $dependencies = $entity->calculateDependencies()->getDependencies();
+    $this->assertEquals(['toolbar'], $dependencies['module']);
+    $this->assertEquals(['olivero'], $dependencies['theme']);
+    $this->assertEquals(['image.style.fallback', 'image.style.large', 'image.style.medium', 'image.style.small'], $dependencies['config']);
+  }
+
+  /**
+   * @covers ::addImageStyleMapping
+   * @covers ::hasImageStyleMappings
+   */
+  public function testHasImageStyleMappings(): void {
+    $entity = new ResponsiveImageStyle([]);
+    $this->assertFalse($entity->hasImageStyleMappings());
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => '',
+    ]);
+    $this->assertFalse($entity->hasImageStyleMappings());
+    $entity->removeImageStyleMappings();
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [],
+      ],
+    ]);
+    $this->assertFalse($entity->hasImageStyleMappings());
+    $entity->removeImageStyleMappings();
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '',
+        'sizes_image_styles' => [
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $this->assertFalse($entity->hasImageStyleMappings());
+    $entity->removeImageStyleMappings();
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $this->assertTrue($entity->hasImageStyleMappings());
+    $entity->removeImageStyleMappings();
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $this->assertTrue($entity->hasImageStyleMappings());
+  }
+
+  /**
+   * @covers ::addImageStyleMapping
+   * @covers ::getImageStyleMapping
+   */
+  public function testGetImageStyleMapping(): void {
+    $entity = new ResponsiveImageStyle(['']);
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $expected = [
+      'breakpoint_id' => 'test_breakpoint',
+      'multiplier' => '1x',
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ];
+    $this->assertEquals($expected, $entity->getImageStyleMapping('test_breakpoint', '1x'));
+    $this->assertNull($entity->getImageStyleMapping('test_unknown_breakpoint', '1x'));
+  }
+
+  /**
+   * @covers ::addImageStyleMapping
+   * @covers ::getKeyedImageStyleMappings
+   */
+  public function testGetKeyedImageStyleMappings(): void {
+    $entity = new ResponsiveImageStyle(['']);
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint', '2x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint2', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'thumbnail',
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint2', '2x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => '_original image_',
+    ]);
+
+    $expected = [
+      'test_breakpoint' => [
+        '1x' => [
+          'breakpoint_id' => 'test_breakpoint',
+          'multiplier' => '1x',
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => 'large',
+        ],
+        '2x' => [
+          'breakpoint_id' => 'test_breakpoint',
+          'multiplier' => '2x',
+          'image_mapping_type' => 'sizes',
+          'image_mapping' => [
+            'sizes' => '(min-width:700px) 700px, 100vw',
+            'sizes_image_styles' => [
+              'large' => 'large',
+            ],
+          ],
+        ],
+      ],
+      'test_breakpoint2' => [
+        '1x' => [
+          'breakpoint_id' => 'test_breakpoint2',
+          'multiplier' => '1x',
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => 'thumbnail',
+        ],
+        '2x' => [
+          'breakpoint_id' => 'test_breakpoint2',
+          'multiplier' => '2x',
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => '_original image_',
+        ],
+      ],
+    ];
+    $this->assertEquals($expected, $entity->getKeyedImageStyleMappings());
+
+    // Add another mapping to ensure keyed mapping static cache is rebuilt.
+    $entity->addImageStyleMapping('test_breakpoint2', '2x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'medium',
+    ]);
+    $expected['test_breakpoint2']['2x'] = [
+      'breakpoint_id' => 'test_breakpoint2',
+      'multiplier' => '2x',
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'medium',
+    ];
+    $this->assertEquals($expected, $entity->getKeyedImageStyleMappings());
+
+    // Overwrite a mapping to ensure keyed mapping static cache is rebuilt.
+    $entity->addImageStyleMapping('test_breakpoint2', '2x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $expected['test_breakpoint2']['2x'] = [
+      'breakpoint_id' => 'test_breakpoint2',
+      'multiplier' => '2x',
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ];
+    $this->assertEquals($expected, $entity->getKeyedImageStyleMappings());
+  }
+
+  /**
+   * @covers ::addImageStyleMapping
+   * @covers ::getImageStyleMappings
+   */
+  public function testGetImageStyleMappings(): void {
+    $entity = new ResponsiveImageStyle(['']);
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint', '2x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint2', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'thumbnail',
+    ]);
+
+    $expected = [
+      [
+        'breakpoint_id' => 'test_breakpoint',
+        'multiplier' => '1x',
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'large',
+      ],
+      [
+        'breakpoint_id' => 'test_breakpoint',
+        'multiplier' => '2x',
+        'image_mapping_type' => 'sizes',
+        'image_mapping' => [
+          'sizes' => '(min-width:700px) 700px, 100vw',
+          'sizes_image_styles' => [
+            'large' => 'large',
+          ],
+        ],
+      ],
+      [
+        'breakpoint_id' => 'test_breakpoint2',
+        'multiplier' => '1x',
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'thumbnail',
+      ],
+    ];
+    $this->assertEquals($expected, $entity->getImageStyleMappings());
+  }
+
+  /**
+   * @covers ::addImageStyleMapping
+   * @covers ::removeImageStyleMappings
+   */
+  public function testRemoveImageStyleMappings(): void {
+    $entity = new ResponsiveImageStyle(['']);
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint', '2x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint2', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'thumbnail',
+    ]);
+
+    $this->assertTrue($entity->hasImageStyleMappings());
+    $entity->removeImageStyleMappings();
+    $this->assertEmpty($entity->getImageStyleMappings());
+    $this->assertEmpty($entity->getKeyedImageStyleMappings());
+    $this->assertFalse($entity->hasImageStyleMappings());
+  }
+
+  /**
+   * @covers ::setBreakpointGroup
+   * @covers ::getBreakpointGroup
+   */
+  public function testSetBreakpointGroup(): void {
+    $entity = new ResponsiveImageStyle(['breakpoint_group' => 'test_group']);
+    $entity->addImageStyleMapping('test_breakpoint', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'large',
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint', '2x', [
+      'image_mapping_type' => 'sizes',
+      'image_mapping' => [
+        'sizes' => '(min-width:700px) 700px, 100vw',
+        'sizes_image_styles' => [
+          'large' => 'large',
+        ],
+      ],
+    ]);
+    $entity->addImageStyleMapping('test_breakpoint2', '1x', [
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => 'thumbnail',
+    ]);
+
+    // Ensure that setting to same group does not remove mappings.
+    $entity->setBreakpointGroup('test_group');
+    $this->assertTrue($entity->hasImageStyleMappings());
+    $this->assertEquals('test_group', $entity->getBreakpointGroup());
+
+    // Ensure that changing the group removes mappings.
+    $entity->setBreakpointGroup('test_group2');
+    $this->assertEquals('test_group2', $entity->getBreakpointGroup());
+    $this->assertFalse($entity->hasImageStyleMappings());
+  }
+
+}