Issue #3358049: Save FieldStorageConfig at the same time as FieldConfig

core/modules/comment/tests/src/Functional/CommentFieldsTest.php

@@ -195,6 +195,42 @@ public function testCommentFieldCreate() {
     $this->assertSession()->statusMessageContains('Saved User comment configuration.', 'status');
   }
 
+  /**
+   * Tests editing a comment field through the interface.
+   */
+  public function testCommentFieldEdit() {
+    // Create user who can administer user fields.
+    $user = $this->drupalCreateUser([
+      'administer user fields',
+    ]);
+    $this->drupalLogin($user);
+
+    // Create a comment type for users.
+    $bundle = CommentType::create([
+      'id' => 'user_comment_type',
+      'label' => 'user_comment_type',
+      'description' => '',
+      'target_entity_type_id' => 'user',
+    ]);
+    $bundle->save();
+    $this->addDefaultCommentField('user', 'user', 'field_user_comment', comment_type_id: 'user_comment_type');
+
+    // Select a comment type and try to save again.
+    $this->drupalGet('admin/config/people/accounts/fields/user.user.field_user_comment/storage');
+    $this->submitForm([], 'Save');
+    // We shouldn't get an error message.
+    $this->assertSession()->pageTextContains('Updated field Comments field settings.');
+
+    // Try to save the comment field with "Comments per page"
+    // setting value as zero.
+    $edit = [
+      'settings[per_page]' => 0,
+    ];
+    $this->drupalGet('admin/config/people/accounts/fields/user.user.field_user_comment');
+    $this->submitForm($edit, 'Save settings');
+    $this->assertSession()->statusMessageContains('Saved Comments configuration.', 'status');
+  }
+
   /**
    * Tests that comment module works when installed after a content module.
    */