Add option "case insensitive"

[Yuri05]

Is it possible to check anchors case insensitive or to add such an option?
E.g. when checking the html below, I get the error error: bad link test.html#Some-Section
However both links "#some-section" and "#Some-Section" should be valid in my context.
Thank you.

<h1>Test</h1>

<a href="#some-section">link</a>
<a href="#Some-Section">link</a>

<h1 id="some-section">Some section</h1>

[untitaker]

are they valid because you're using JS? the provided html snippet, pasted into a html file and opened with firefox does not have both links working

[Yuri05]

For me both links work when opening the html e.g. in MS Edge (on Windows).
But in fact I am checking the cross references within (GitHub flavored) Markdown documents, which I convert to html first

[untitaker]

Can you try with other browsers? I don't have access to a windows machine

[Yuri05]

As I mentioned, my primary intention is to validate cross-references in (GitHub flavored) Markdown (gfm) documents.
Here is an example: https://github.com/Yuri05/TestReport/blob/main/test.md

In this file, there one chapter and one html anchor (which is supported by gfm) are defined:

<a id="introduction_anchor"></a>
## 1 Introduction

At the beginning of the document, 4 cross-references are defined:

# Valid links
[Valid chapter link](#1-introduction) <br>
[Valid chapter link case insensitive](#1-Introduction) <br>
[Valid anchor link](#introduction_anchor) <br>
[Valid anchor link case insensitive](#Introduction_Anchor) <br>

Now when I open this md file in a browser (on Windows) - all those 4 links work (tried it with Firefox, Edge and Chrome).
But when checking the converted html: 2 links are reported as invalid because of the case sensitive check

Error: bad anchors:
  test.html#1-Introduction
  test.html#Introduction_Anchor

[untitaker]

I don't think i can help here. You are converting the Markdown to HTML in a fundamentally different way than GitHub does. GitHub uses a ton of JS to make anchors work (the resulting DOM does not contain the element IDs verbatim), and for some reason they do it case-insensitively.

I think you have two options:

• You adjust your markdown conversion process to mimick what GitHub does to anchors, but without JS. From what I can tell this might just mean lowercasing IDs and links to anchors.
• Use lychee, not hyperlink. It is a linkchecker that directly validates markdown files and the primary usecase is validating links in READMEs. I am not sure whether it supports anchors in markdown files, but if not, a feature request there would be more in-scope than here.

[Yuri05]

Use lychee, not hyperlink. It is a linkchecker that directly validates markdown files and the primary usecase is validating links in READMEs. I am not sure whether it supports anchors in markdown files...

Already tried before - it does not :)

... but if not, a feature request there would be more in-scope than here.

OK.

[untitaker]

maybe this helps: https://github.com/phseiff/github-flavored-markdown-to-html