Incorrect anchor link including an underscore character

[ybiquitous]

🐛 Bug Report

When an underscore character (_) is included in an anchor link, Docusaurus converts the underscore to a hyphen (e.g. #foo_bar → #foo-bar).

This behavior is different from GitHub's one, so it's very confusing. 😓

Have you read the Contributing Guidelines on issues?

Yes. 👍

To Reproduce

1. Run git clone https://github.com/ybiquitous/docusaurus-sandbox on your terminal.
2. Run cd docusaurus-sandbox/website.
3. Run yarn install.
4. Run yarn run start.
5. Open http://localhost:3001/docs/doc1 page on your browser.
6. Click foo_bar link on the page.

Expected behavior

Jump to the #foo_bar section.

Actual Behavior

Not Jump to the #foo_bar section.

Reproducible Demo

https://github.com/ybiquitous/docusaurus-sandbox

Environment:

• Node 10.15.3
• Yarn 1.15.2
• Docusaurus 1.7.3

[ybiquitous]

Here is a GitHub's behavior:

I hope Docusaurus would behave as same. 🙏

[endiliey]

What a tricky bug !

I made some test of headings https://gist.github.com/endiliey/f5256045e80c1c10436c6bdfce9c5961
Seems that it replaces all special characters except _ to -
Docusaurus only replaces all special characters to -

[ybiquitous]

Thank you so much for the quick fix! 😂