Spaces are no longer valid in links

[Sainan]

Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

We recently upgraded from Docusaurus 2 to 3.1.1 and this is one of our links that broke: [constexpr attribute](Constexpr Attribute.md)

It seems the space within the parentheses is no longer valid now. However, it is valid when I either use %20 or angle brackets: (<Constexpr Attribute.md>)

This doesn't seem to be documented as an intentional breaking change from 3, so probably an unintentional break?

Reproducible demo

No response

Steps to reproduce

1. Create two markdown files, one with a space in the name.
2. Try to link the markdown file with the space in the name.

Expected behavior

It would make a link.

Actual behavior

The markdown link is not interpreted, instead dumped into the build as plain text.

Your environment

• Docusaurus version used: 3.1.1

Self-service

• I'd be willing to fix this bug myself.

[Josh-Cena]

Your original syntax was not a valid Markdown link. You can try here: https://mdxjs.com/playground/

It was a bug that Docusaurus mapped it to a valid Markdown link.

[Sainan]

Fair on not being valid Markdown. Still an undocumented breaking change. 😕

[slorber]

A bugfix is not a breaking change

You have to read the full Changelog to read about bugfixes, documenting all of them would be overwhelming.

[Sainan]

It is when it was a bug people were relying on.