tests/src/Kernel/EntityEmbedFilterTest.php | 126 +++++++++++++----------------
 1 file changed, 56 insertions(+), 70 deletions(-)

diff --git a/tests/src/Kernel/EntityEmbedFilterTest.php b/tests/src/Kernel/EntityEmbedFilterTest.php
index b41ad66..1beae9c 100644
--- a/tests/src/Kernel/EntityEmbedFilterTest.php
+++ b/tests/src/Kernel/EntityEmbedFilterTest.php
@@ -56,12 +56,6 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
     $embedded_entity_container = $this->cssSelect('div.embedded-entity')[0];
     $this->assertHasAttributes($embedded_entity_container, $expected_attributes);
 
-    // Specifically assert the absence of `data-entity-id` if it wasn't present
-    // on input either.
-    if (empty($embed_attributes['data-entity-id'])) {
-      $this->assertFalse(isset($embedded_entity_container['data-entity-id']));
-    }
-
     // Expected bubbleable metadata.
     $this->assertSame($result->getCacheTags(), $expected_cacheability->getCacheTags());
     $this->assertSame($result->getCacheContexts(), $expected_cacheability->getCacheContexts());
@@ -81,10 +75,10 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
     $expected_asset_libraries = ['entity_embed/caption'];
 
     return [
-      'using entity ID and view mode' => [
+      '`data-entity-uuid` + `data-view-mode` ⇒ rendered' => [
         'embed_attributes' => [
           'data-entity-type' => 'node',
-          'data-entity-id' => 1,
+          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
           'data-view-mode' => 'teaser',
         ],
         'contains' => [
@@ -93,7 +87,6 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
         'not_contains' => [],
         'expected_attributes' => [
           'data-entity-type' => 'node',
-          'data-entity-id' => 1,
           'data-view-mode' => 'teaser',
           'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
           'data-langcode' => 'en',
@@ -105,10 +98,10 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
         'expected_cacheability' => $expected_cacheability,
         'expected_asset_libraries' => $expected_asset_libraries,
       ],
-      'embedded entity is not rendered if unpublished' => [
+      'data-entity-uuid + data-view-mode; unpublished ⇒ NOT rendered' => [
         'embed_attributes' => [
           'data-entity-type' => 'node',
-          'data-entity-id' => 1,
+          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
           'data-view-mode' => 'teaser',
         ],
         'contains' => [],
@@ -119,17 +112,16 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
         'expected_cacheability' => $expected_cacheability,
         'expected_asset_libraries' => $expected_asset_libraries,
       ],
-      'Unpublished and current user has view unpublished permission' => [
+      'data-entity-uuid + data-view-mode; unpublished + `view own unpublished` ⇒ rendered' => [
         'embed_attributes' => [
           'data-entity-type' => 'node',
-          'data-entity-id' => 1,
+          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
           'data-view-mode' => 'teaser',
         ],
         'contains' => ['This node is to be used for embedding in other nodes.'],
         'not_contains' => [],
         'expected_attributes' => [
           'data-entity-type' => 'node',
-          'data-entity-id' => 1,
           'data-view-mode' => 'teaser',
           'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
           'data-langcode' => 'en',
@@ -142,54 +134,6 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
           ->setCacheContexts(['timezone', 'user', 'user.permissions']),
         'expected_asset_libraries' => $expected_asset_libraries,
       ],
-      'using entity UUID and view mode' => [
-        'embed_attributes' => [
-          'data-entity-type' => 'node',
-          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
-          'data-view-mode' => 'teaser',
-        ],
-        'contains' => [
-          'This node is to be used for embedding in other nodes.',
-        ],
-        'not_contains' => [],
-        'expected_attributes' => [
-          'data-entity-type' => 'node',
-          'data-view-mode' => 'teaser',
-          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
-          'data-langcode' => 'en',
-          'data-entity-embed-display' => 'entity_reference:entity_reference_entity_view',
-          'data-entity-embed-display-settings' => 'teaser',
-        ],
-        'published' => TRUE,
-        'view_unpublished' => FALSE,
-        'expected_cacheability' => $expected_cacheability,
-        'expected_asset_libraries' => $expected_asset_libraries,
-      ],
-      'Ensure that UUID is preferred over ID when both attributes are present' => [
-        'embed_attributes' => [
-          'data-entity-type' => 'node',
-          'data-entity-id' => 2,
-          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
-          'data-view-mode' => 'teaser',
-        ],
-        'contains' => [
-          'This node is to be used for embedding in other nodes.',
-        ],
-        'not_contains' => [],
-        'expected_attributes' => [
-          'data-entity-type' => 'node',
-          'data-entity-id' => 2,
-          'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
-          'data-view-mode' => 'teaser',
-          'data-langcode' => 'en',
-          'data-entity-embed-display' => 'entity_reference:entity_reference_entity_view',
-          'data-entity-embed-display-settings' => 'teaser',
-        ],
-        'published' => TRUE,
-        'view_unpublished' => FALSE,
-        'expected_cacheability' => $expected_cacheability,
-        'expected_asset_libraries' => $expected_asset_libraries,
-      ],
       'Test deprecated default Entity Embed Display plugin.' => [
         'embed_attributes' => [
           'data-entity-type' => 'node',
@@ -292,7 +236,7 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
       "Ensure that content that can't be loaded is replaced with warning" => [
         'embed_attributes' => [
           'data-entity-type' => 'node',
-          'data-entity-id' => 'InvalidID',
+          'data-entity-uuid' => 'InvalidID',
           'data-view-mode' => 'teaser',
         ],
         'contains' => [],
@@ -305,10 +249,9 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
    * Test HTML tag with same attributes as drupal-entity not affected.
    */
   public function testContainerTagElementReplace() {
-    $node_id = $this->node->id();
     $content = $this->createEmbedCode([
       'data-entity-type' => 'node',
-      'data-entity-id' => $node_id,
+      'data-entity-uuid' => $this->node->uuid(),
       'data-view-mode' => 'teaser',
     ]);
 
@@ -438,6 +381,54 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
     $this->assertRaw($this->node->body->value);
   }
 
+  /**
+   * Tests BC for `data-entity-uuid`'s predecessor, `data-entity-id`.
+   *
+   * @group legacy
+   */
+  public function testEntityIdBackwardsCompatibility() {
+    $content = $this->createEmbedCode([
+      'data-entity-type' => 'node',
+      'data-entity-id' => 1,
+      'data-view-mode' => 'teaser',
+    ]);
+    $this->applyFilter($content);
+    $this->assertHasAttributes($this->cssSelect('div.embedded-entity')[0], [
+      'data-entity-type' => 'node',
+      'data-entity-id' => 1,
+      'data-view-mode' => 'teaser',
+      'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
+      'data-langcode' => 'en',
+      'data-entity-embed-display' => 'entity_reference:entity_reference_entity_view',
+      'data-entity-embed-display-settings' => 'teaser',
+    ]);
+  }
+
+  /**
+   * Verifies `data-entity-id` is ignored when `data-entity-uuid` is present.
+   *
+   * @group legacy
+   */
+  public function testEntityIdIgnoredIfEntityUuidPresent() {
+    $nonsensical_id = $this->randomMachineName();
+    $content = $this->createEmbedCode([
+      'data-entity-type' => 'node',
+      'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
+      'data-entity-id' => $nonsensical_id,
+      'data-view-mode' => 'teaser',
+    ]);
+    $this->applyFilter($content);
+    $this->assertHasAttributes($this->cssSelect('div.embedded-entity')[0], [
+      'data-entity-type' => 'node',
+      'data-entity-id' => $nonsensical_id,
+      'data-view-mode' => 'teaser',
+      'data-entity-uuid' => 'e7a3e1fe-b69b-417e-8ee4-c80cb7640e63',
+      'data-langcode' => 'en',
+      'data-entity-embed-display' => 'entity_reference:entity_reference_entity_view',
+      'data-entity-embed-display-settings' => 'teaser',
+    ]);
+  }
+
   /**
    * Tests BC for`data-entity-embed-display-settings`'s predecessor.
    *
@@ -500,11 +491,6 @@ class EntityEmbedFilterTest extends EntityEmbedFilterTestBase {
         ->loadByProperties(['uuid' => $attributes['data-entity-uuid']]);
       $entity = current($entity);
     }
-    elseif (!empty($attributes['data-entity-id'])) {
-      $entity = $this->container->get('entity_type.manager')
-        ->getStorage($attributes['data-entity-type'])
-        ->load($attributes['data-entity-id']);
-    }
     if ($entity && $entity instanceof TranslatableInterface && !empty($attributes['data-langcode'])) {
       if ($entity->hasTranslation($attributes['data-langcode'])) {
         $entity = $entity->getTranslation($attributes['data-langcode']);