Throw an exception if a component property's `type` contains non-string values

Added the test that will fail with such definition. It is practically useless, I think, but it shows that the input and expected data are not the same. If you try to render it, a PHP error occurs. Maybe we should throw an exception in that case, I don't know.

I propose to throw an exception if the types of the property contain values that are not strings, which will include floats and special YAML types. We definitely do not want to correct the value !!float 12.3 in any way. We should throw a meaningful exception, indicating the component ID and property name. Then developers can easily identify and fix the problem.

If we are going to fix NULL for developers automatically, we still have to check for other types and throw an exception. So it's just more code with basically the same result.

Added check for property type definition values, and if it contains a non-string value, throws an exception. In my case, it is now clear where the problem is:

Drupal\Core\Render\Component\Exception\InvalidComponentException: The component "foo:bar" uses non-string types for properties: required. in Drupal\Core\Theme\Component\ComponentValidator->validateDefinition() (line 96 of core/lib/Drupal/Core/Theme/Component/ComponentValidator.php).

$schema: https://git.drupalcode.org/project/drupal/-/raw/HEAD/core/assets/schemas/v1/metadata.schema.json
name: Bar
props:
  type: object
  properties:
    required:
      type: [null, boolean]
      title: Required

Tried to get some feedback in the slack channel #components but no luck.

Believe this is a net improvement for sure though

Test-only feature shows that

1) Drupal\Tests\Core\Theme\Component\ComponentValidatorTest::testValidateDefinitionInvalid with data set #3 (['https://git.drupalcode.org/pr...a.json', 'Call to Action', 'My description', ['object', ['text'], [[null, 'Title', 'The title for the cta', ['Press', 'Submit now']], ['string', 'URL', 'uri'], ['string', 'Target', ['', '_blank']], ['Drupal\Core\Template\Attribute', 'Attributes']]], 'my-cta', 'module', 'sdc_test:my-cta', [[[[]]]], '', 'sdc_test', 'my-cta.twig', 'my-group'])
Failed asserting that exception of type "Drupal\Core\Render\Component\Exception\InvalidComponentException" is thrown.
2) Drupal\Tests\Core\Theme\Component\ComponentValidatorTest::testValidateDefinitionInvalid with data set #4 (['https://git.drupalcode.org/pr...a.json', 'Call to Action', 'My description', ['object', ['text'], [[['string', null], 'Title', 'The title for the cta', ['Press', 'Submit now']], ['string', 'URL', 'uri'], ['string', 'Target', ['', '_blank']], ['Drupal\Core\Template\Attribute', 'Attributes']]], 'my-cta', 'module', 'sdc_test:my-cta', [[[[]]]], '', 'sdc_test', 'my-cta.twig', 'my-group'])
Failed asserting that exception of type "TypeError" matches expected exception "Drupal\Core\Render\Component\Exception\InvalidComponentException". Message was: "Drupal\Core\Theme\Component\ComponentValidator::Drupal\Core\Theme\Component\{closure}(): Argument #1 ($type) must be of type string, null given" at
/builds/issue/drupal-3462156/core/lib/Drupal/Core/Theme/Component/ComponentValidator.php:278
/builds/issue/drupal-3462156/core/lib/Drupal/Core/Theme/Component/ComponentValidator.php:84
/builds/issue/drupal-3462156/core/tests/Drupal/Tests/Core/Theme/Component/ComponentValidatorTest.php:62

I don't see that anyone has received the code for this issue, only that the test only feature has been used. Remember, issues do need a code review. I thought at first that this was throwing a new exception but I see that it is not. I do think a comment is needed, which I indicated in the MR, perhaps some of the detail in #4 would be useful there.

The title here should include some indication of what this fix applies to. The title should be a description of what is being fixed or improved. The title is used as the git commit message so it should be meaningful an concise. See List of issue fields → .

So, two small things, although this still needs a review by someone familiar with this component.

Added comment and adjusting issue title

Believe title reflects the change so removing that tag.

Also appears additional feedback has been addressed

I think the test could be slightly clearer (see MR comment), but I think this is ready nonetheless 👍