Entity API Validation - inconsistent returned field IDs

Hi there!

Currently making some test with a headless D8 and trying out the Entity Validation API.

I am using only the server side validation.

Based on the returned error, I need to map the error with the field having the error.

I have been playing with validation on title field, here is what I got:

When no data in title, I get this error:

Unprocessable Entity: validation failed. title: This value should not be null.

When adding constraint:

function mymodule_entity_bundle_field_info_alter(&$fields, \Drupal\Core\Entity\EntityTypeInterface $entity_type, $bundle) {
  if ($entity_type->id() == 'node' && $bundle == 'customer') {
    $fields['title']->addPropertyConstraints('value', ['Length' => ['min' => 3, 'max' => 10]]);
  }
}

I get this error:

Unprocessable Entity: validation failed. title.0.value: This value is too short. It should have 3 characters or more.

The field key are not the same. Is there any way to have the same structure? That would help a lot!

Also, is there a way to get the errors not formatted. Right now, I get a string, which I will have to manually split to extract the field ID and the error. It would be much simpler if I was able to get an array containing all errors, keyed by field ID for example.

Thanks!

Ed