Handle null nextDescription in describeElement

[jalada]

Description of the change

Handle when describeElement returns null e.g. if the element isn't something that has a tag name etc.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

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[matux]

Suggested change

	if (!nextDescription || nextDescription.tagName === 'html') {
	if (nextDescription == null || nextDescription.tagName?.toLowerCase() === 'html') {

[jalada]

Do you need the ? if it's null? The code in describeElement looks like it reliably sets a tagname if not. It also already calls toLowerCase() when setting it.

Just being extra defensive?