Some auto-generated TOC links do not match corresponding header anchors

[aspiers]

• [x] I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

Generate a TOC with the markdown.slugify option set to use the default slugify from @vuepress/shared-utils. For example, see the .vuepress/config.js for hardhat.org.

What is expected?

Links from the TOC will correctly navigate to the corresponding auto-generated header anchors.

What is actually happening?

Some header links don't match the auto-generated header anchors.

Examples of inconsistencies:

• Slugs for duplicate headers start with a -1 prefix in the TOC anchor link but a -2 prefix for the header anchor
• / character in headers get removed in the TOC anchor link, but replaced with - in the header anchor
• Headers starting with numbers seem to get slugs prefixed with _ only in the header anchor, not in the TOC link. So for example a header 1. node task gets slugified to #1-node-task in the TOC anchor link, but to #_1-node-task in the header anchor

Other relevant information

Please see https://hardhat.org/plugins/hardhat-deploy.html for a specific public example, and https://github.com/nomiclabs/hardhat/issues/1800 for the corresponding issue.

[aspiers]

I am confused where these inconsistencies are coming from, because I thought the same slugify function was supposed to handle anchor generation both for the TOC links and header anchors?

[aspiers]

Ah, I see there is a markdown.toc option, which says:

(Note: prefer markdown.slugify to customize header ids.)

but it looks the toc plugin is indeed using the same slugify:

https://github.com/vuejs/vuepress/blob/38e98634af117f83b6a32c8ff42488d91b66f663/packages/%40vuepress/markdown/index.js#L97-L102

which is defined here:

https://github.com/vuejs/vuepress/blob/38e98634af117f83b6a32c8ff42488d91b66f663/packages/%40vuepress/markdown/index.js#L45-L46

so I'm not sure what's going wrong. Perhaps parseHeaders is interfering somehow?