diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableDisplayBase.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableDisplayBase.php
new file mode 100644
index 0000000000..964185b589
--- /dev/null
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableDisplayBase.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Drupal\Tests\comment\Kernel\Migrate\d6;
+
+use Drupal\Tests\migrate_drupal\Kernel\d6\MigrateDrupal6TestBase;
+
+/**
+ * Base class for Drupal 6 comment variables to Drupal 8 entity display tests.
+ */
+abstract class MigrateCommentVariableDisplayBase extends MigrateDrupal6TestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['comment'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->installConfig(['comment']);
+    $this->migrateContentTypes();
+    $this->executeMigrations([
+      'd6_comment_type',
+      'd6_comment_field',
+      'd6_comment_field_instance',
+    ]);
+  }
+
+}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityDisplayTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityDisplayTest.php
new file mode 100644
index 0000000000..a98c374bed
--- /dev/null
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityDisplayTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Drupal\Tests\comment\Kernel\Migrate\d6;
+
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+
+/**
+ * Upgrade comment variables to entity.display.node.*.default.yml.
+ *
+ * @group comment
+ * @group migrate_drupal_6
+ * @group legacy
+ */
+class MigrateCommentVariableEntityDisplayTest extends MigrateCommentVariableDisplayBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['menu_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->executeMigration('d6_comment_entity_display');
+  }
+
+  /**
+   * Tests comment variables migrated into an entity display.
+   */
+  public function testCommentEntityDisplay() {
+    foreach (['page', 'story', 'article'] as $type) {
+      $component = EntityViewDisplay::load('node.' . $type . '.default')->getComponent('comment');
+      $this->assertIdentical('hidden', $component['label']);
+      $this->assertIdentical('comment_default', $component['type']);
+      $this->assertIdentical(20, $component['weight']);
+    }
+  }
+
+}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityFormDisplaySubjectTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityFormDisplaySubjectTest.php
new file mode 100644
index 0000000000..6e74bb9949
--- /dev/null
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityFormDisplaySubjectTest.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace Drupal\Tests\comment\Kernel\Migrate\d6;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Tests\migrate_drupal\Kernel\d6\MigrateDrupal6TestBase;
+
+/**
+ * Upgrade comment subject variable to core.entity_form_display.comment.*.default.yml
+ *
+ * @group comment
+ * @group migrate_drupal_6
+ * @group legacy
+ */
+class MigrateCommentVariableEntityFormDisplaySubjectTest extends MigrateDrupal6TestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['comment'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->installConfig(['comment']);
+    $this->executeMigrations([
+      'd6_comment_type',
+      'd6_comment_entity_form_display_subject',
+    ]);
+  }
+
+  /**
+   * Tests comment subject variable migrated into an entity display.
+   */
+  public function testCommentEntityFormDisplay() {
+    $component = EntityFormDisplay::load('comment.comment.default')
+      ->getComponent('subject');
+    $this->assertIdentical('string_textfield', $component['type']);
+    $this->assertIdentical(10, $component['weight']);
+    $component = EntityFormDisplay::load('comment.comment_no_subject.default')
+      ->getComponent('subject');
+    $this->assertNull($component);
+  }
+
+}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityFormDisplayTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityFormDisplayTest.php
new file mode 100644
index 0000000000..e7432ca107
--- /dev/null
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableEntityFormDisplayTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Drupal\Tests\comment\Kernel\Migrate\d6;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+
+/**
+ * Upgrade comment variables to core.entity_form_display.node.*.default.yml.
+ *
+ * @group comment
+ * @group migrate_drupal_6
+ * @group legacy
+ */
+class MigrateCommentVariableEntityFormDisplayTest extends MigrateCommentVariableDisplayBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['menu_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->executeMigration('d6_comment_entity_form_display');
+  }
+
+  /**
+   * Tests comment variables migrated into an entity display.
+   */
+  public function testCommentEntityFormDisplay() {
+    foreach (['page', 'article', 'story'] as $type) {
+      $component = EntityFormDisplay::load('node.' . $type . '.default')
+        ->getComponent('comment');
+      $this->assertIdentical('comment_default', $component['type']);
+      $this->assertIdentical(20, $component['weight']);
+    }
+  }
+
+}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableFieldTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableFieldTest.php
new file mode 100644
index 0000000000..74169b084b
--- /dev/null
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableFieldTest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Drupal\Tests\comment\Kernel\Migrate\d6;
+
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\migrate_drupal\Kernel\d6\MigrateDrupal6TestBase;
+
+/**
+ * Upgrade comment variables to field.storage.node.comment.yml.
+ *
+ * @group comment
+ * @group migrate_drupal_6
+ * @group legacy
+ */
+class MigrateCommentVariableFieldTest extends MigrateDrupal6TestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['comment', 'menu_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->installConfig(['comment']);
+    $this->migrateContentTypes();
+    $this->executeMigrations(['d6_comment_type', 'd6_comment_field']);
+  }
+
+  /**
+   * Tests comment variables migrated into a field entity.
+   */
+  public function testCommentField() {
+    $this->assertTrue(is_object(FieldStorageConfig::load('node.comment')));
+  }
+
+}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableInstanceTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableInstanceTest.php
new file mode 100644
index 0000000000..5822a86594
--- /dev/null
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentVariableInstanceTest.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace Drupal\Tests\comment\Kernel\Migrate\d6;
+
+use Drupal\comment\CommentManagerInterface;
+use Drupal\Tests\migrate_drupal\Kernel\d6\MigrateDrupal6TestBase;
+use Drupal\node\Entity\Node;
+
+/**
+ * Upgrade comment variables to field.instance.node.*.comment.yml.
+ *
+ * @group comment
+ * @group migrate_drupal_6
+ * @group legacy
+ */
+class MigrateCommentVariableInstanceTest extends MigrateDrupal6TestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['comment', 'menu_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->installConfig(['comment']);
+    $this->migrateContentTypes();
+    $this->executeMigrations([
+      'd6_comment_type',
+      'd6_comment_field',
+      'd6_comment_field_instance',
+    ]);
+  }
+
+  /**
+   * Test the migrated field instance values.
+   */
+  public function testCommentFieldInstance() {
+    $node = Node::create(['type' => 'page']);
+    $this->assertIdentical(0, $node->comment->status);
+    $this->assertIdentical('comment', $node->comment->getFieldDefinition()->getName());
+    $settings = $node->comment->getFieldDefinition()->getSettings();
+    $this->assertIdentical(CommentManagerInterface::COMMENT_MODE_THREADED, $settings['default_mode']);
+    $this->assertIdentical(50, $settings['per_page']);
+    $this->assertFalse($settings['anonymous']);
+    $this->assertFalse($settings['form_location']);
+    $this->assertTrue($settings['preview']);
+
+    $node = Node::create(['type' => 'story']);
+    $this->assertIdentical(2, $node->comment_no_subject->status);
+    $this->assertIdentical('comment_no_subject', $node->comment_no_subject->getFieldDefinition()->getName());
+    $settings = $node->comment_no_subject->getFieldDefinition()->getSettings();
+    $this->assertIdentical(CommentManagerInterface::COMMENT_MODE_FLAT, $settings['default_mode']);
+    $this->assertIdentical(70, $settings['per_page']);
+    $this->assertTrue($settings['anonymous']);
+    $this->assertFalse($settings['form_location']);
+    $this->assertFalse($settings['preview']);
+  }
+
+}