1.5: HeadingPermalinkProcessor::getChildText() strips out AbstractStringContainer from link

[Ambient-Impact]

Description
I know that HeadingPermalinkProcessor::getChildText() is going to be removed in 2.0, but I'm stuck with 1.5 for the foreseeable future. I assumed any class that extends AbstractStringContainer would have its text contents included in the permalink, but it seems that instanceof Text and instanceof Code are hard coded. Is there a reason for this, or can it be expanded to instanceof AbstractStringContainer?

Example
I'm helping bring 8fold/commonmark-abbreviations closer in line with CommonMark core (see 8fold/commonmark-abbreviations#8), and when an Abbreviation is present in the heading text, even with the pull request to extend AbstractStringContainer, the text content is completely ignored by the heading permalink.

[Ambient-Impact]

Upon poking around, it seems like this issue can be worked around with a custom text normalizer:

class YourNormalizer implements TextNormalizerInterface {

  /**
   * {@inheritdoc}
   */
  public function normalize(string $text, $context = null): string {
    if (
      \is_object($context) &&
      \method_exists($context, 'getStringContent') &&
      !empty($context->getStringContent())
    ) {
      $text = $context->getStringContent();
    }

    // Rest of normalizer processing goes here.

  }

}

[colinodell]

I assumed any class that extends AbstractStringContainer would have its text contents included in the permalink, but it seems that instanceof Text and instanceof Code are hard coded. Is there a reason for this, or can it be expanded to instanceof AbstractStringContainer?

I honestly can't recall why the other node types were excluded.

Given that 2.0 allows other types including AbstractStringContainer, I don't see any obvious reasons why we can't allow this in 1.x too.

Would you be okay if we changed this behavior in 1.6.1? Or do you really need this in 1.5?

[Ambient-Impact]

Given the workaround I posted, it's no rush and fine in 1.6.1. Thanks! 🤓

[colinodell]

Fixed via a70a586 and released in 1.6.1.

Thanks for reporting this!

[Ambient-Impact]

Awesome, thanks!