Remove paragraph from list items in table of contents

[froschdesign]

Description

The generator for table of contents creates a paragraph for each list item:

commonmark/src/Extension/TableOfContents/TableOfContentsGenerator.php

Lines 108 to 111 in 37eb9a4

	$paragraph = new Paragraph();
	$paragraph->setStartLine($heading->getStartLine());
	$paragraph->setEndLine($heading->getEndLine());
	$paragraph->appendChild($link);

A list item can contain a p element and any other flow content but the list item element defines and creates already a physically separated block. And since only one single link is included at a time, there is no need to add another block.

Regardless, additional spacing is added that needs to be removed to get a normal list design.
This will also help with most frontend frameworks as they also do not use paragraphs in navigation.

Current Behaviour

<ul class="table-of-contents">
    <li>
        <p><a href="#level-2-heading">Level 2 Heading</a></p>
    </li>
    <li>
        <p><a href="#level-4-heading">Level 4 Heading</a></p>
    </li>
    <li>
        <p><a href="#level-3-heading">Level 3 Heading</a></p>
    </li>
</ul>

New Behaviour

<ul class="table-of-contents">
    <li>
        <a href="#level-2-heading">Level 2 Heading</a>
    </li>
    <li>
        <a href="#level-4-heading">Level 4 Heading</a>
    </li>
    <li>
        <a href="#level-3-heading">Level 3 Heading</a>
    </li>
</ul>

[colinodell]

This proposal makes sense to me. We'll probably want to deprecate this in 1.x (perhaps even providing an option to disable it?) and then remove the <p> tags in 2.0.

[colinodell]

I've just remembered that 1.x does not allow rendering children that are a mix of inlines (like links) and blocks (like nested list blocks) when they co-exist as siblings in the AST. This means that my proposed solution above won't work in 1.x. I'll instead drop the <p> tags completely in 2.0 and ensure the changelog and upgrading guide highlight this change.

[froschdesign]

@colinodell
Lightning-fast implementation, great!
I have already tested it and it works like a charm. (Version 2 as a target version is no problem for me.)

Thank you very much for that! 👍 👍 👍