Cannot add a custom block with a block description already used by a non-reusable block

1. +++ b/core/modules/block_content/tests/src/Functional/BlockContentValidationTest.php
   @@ -37,4 +37,27 @@ public function testValidation() {
   +  /**
   +   * Tests block label validation.
   +   */
   +  public function testLabelValidation() {
   

   The testValidation() method in this class already check for the validation message so I think we could just add this to the existing test and do another case where it should not exist.

2. Here is patch creates a new UniqueBlockContentLabelValueValidator. I have changed UniqueFieldValueValidator to add a getEntityQuery() method. This allows use to extend this and just add
   $query->condition('reusable', 1);

   We could also just copy logic from UniqueFieldValueValidator and not extend it. But it seems useful to have a "unique with conditions" ability in other validators.

This works as expected and solves the problem for us! Thank you!

patch doesn't apply anymore

reroll

Hey @tedbow

1. the patch application fails with following error:
   Hunk #3 FAILED at 55.
   1 out of 3 hunks FAILED -- saving rejects to file core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/UniqueFieldValueValidator.php.rej
2. after manual application of the patch,
   • it is possible to create a new custom block at admin/structure/block/block-content with same description as used for a non-reusable block but,
   • now it throws error when same title is used to add the translation of the same non-reusable block (using layout builder).

   without the patch the translations works fine.

Tested with Drupal 8.7.5, with layouts builders + multi-lingual

UPDATE: the patch 3054197-8 not failing with core 8.8.x

As mentioned here and from above comment

The BlockContentInlineBlockTranslateForm also validates using an _entity_form with BlockContent.php as entity type, which is not the case for creating and updating InlineBlock originally.

It would be ideal to validate the block_content only if there are reusable. Attaching the patch and interdiff to review.

And the above patch 3054197-8 is not failing with 8.8.x.

I'm not sure how to test the translation part, but the patch in #10 applies and works for 8.9.

I have verified the above ticket and found that it is working fine on Drupal 9.1.x as expected. This seems to be working as expected without applying patch.

Applied patch #10 on 9.2.x and it doesn't fix this issue.I'm still getting that error after applying this patch.

Abhijith S, I check the scenario like below and seems to be working as expected:

1. I enabled Layout builder, and added blocks to a "Content type", with name "Testing"
2. Now I created a custom block here, "admin/structure/block/block-content", with name "Testing" and it gets created without any error

I think you must be testing it by directly adding it form custom blocks, that's why its giving validation error, please check this: Allow Custom blocks to be set as non-reusable adding access restriction based on where it was used.

Thanks

Rerolled for 9.2.x, #10 was failing to apply cleanly.

This statement was failing the patch.

@@ -39,4 +39,27 @@ public function testValidation() {		@@ -42,4 +42,27 @@ public function testValidation() {
     ]));		     $this->assertEqual(new FormattableMarkup('A custom block with block description %value already exists.', ['%value' => $block->label()]), $violations[0]->getMessage());
   }

Thanks.

I was thinking - why do we even force block titles to be unique at all? I did some searching and finally found the source of this: #1998658: Creating Custom Block with same name as existing block throws SQL error

I have to dig more - but I don't think that SQL error is still relevant? There's nothing in the database table that indicates it must be unique.

Maybe we should instead just open a separate issue to allow blocks to have duplicate titles? Why should content blocks be any different than Nodes in this regard (which allow duplicate titles).

Re-rolled #19 for 9.4

Drupal 9.4.x-dev
Verified and tested patch #23.
Patch applied successfully and looks good for me.
Sharing screenshot for the reference.
Moving this ticket to RTBC.

After investigation I found the UniqueField constraint is useless and it is an heritage from the old custom block module. More info could be found here:

#3272969: Remove unique constraint on block content info field

Wondering if this is still an issue if the unique constraint is dropped in https://www.drupal.org/project/drupal/issues/3272969

After speaking with @larowlan on slack.

its a hark-back to d7 era DB where the 'info' key formed the block plugin ID
we don't need that anymore because we use the block content uuid (edited)

And in https://www.drupal.org/project/drupal/issues/3272969 we are removing the constraint. So closing out as duplicate.