Docusaurus: "navbar.logo.alt" is not allowed to be empty

[Vinnl]

🐛 Bug Report

When I use an empty string for navbar.logo.alt in my config, I get the following validation error:

"navbar.logo.alt" is not allowed to be empty

However, since the logo in my navbar is redundant with the actual project name next to it, I don't want screen readers to read out anything for the logo - it would just duplicate the project name.

Have you read the Contributing Guidelines on issues?

I did now.

To Reproduce

(Write your steps here:)

1. Create a new Docusarus v2 project.
2. Set navbar.logo.alt in themeConfig in docusaurus.config.js to ''.
3. Run npm start.

Expected behavior

The website to start just fine.

Actual Behavior

You get the following output:

A validation error occured.
The validation system was added recently to Docusaurus as an attempt to avoid user configuration errors.
We may have made some mistakes.
If you think your configuration is valid and should keep working, please open a bug report.

ValidationError: "navbar.logo.alt" is not allowed to be empty

Your Environment

• Docusaurus version used: Alpha 61 of v2
• Environment name and version (e.g. Chrome 78.0.3904.108, Node.js 10.17.0): Node v12.18.2
• Operating system and version (desktop or mobile): Ubuntu 20.04

Reproducible Demo

Just the default generated template, with the alt changed.

[slorber]

Hi,

In my opinion it is better that the screen reader reads your alt text vs the image filename

[Vinnl]

@slorber That is about leaving out the alt attribute altogether :) I want to specify an empty alt tag, i.e. <img src="logo.svg" alt=""/>.

See also https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Img#Attributes

[slorber]

I see.

Do you have a link from an authority that claims alt="" is a recommended practice in some cases?

[Vinnl]

@slorber Just added it to my previous comment! :)

[slorber]

thanks, will accept a PR (just need .allow('') in theme validation) or will make one soon