[docs][joy] Error in the exemplary Codesandbox of using Material UI and Joy UI together

[egazarian]

Duplicates

• I have searched the existing issues

Latest version

• I have tested the latest version

Steps to reproduce 🕹

Link to live example: https://codesandbox.io/s/material-ui-feat-joy-ui-vvvv59?file=/demo.tsx
This is the official code sandbox of the guide Joy UI and Material UI together (Case A: Joy UI in a Material UI project).

Steps:

1. Run the app.

Current behavior 😯

The app throws this kind of error: "Cannot read properties of undefined (reading '[property]')".
[property] can be "xl", "sm" etc...

Expected behavior 🤔

The app should starts without any error.

Context 🔦

I'am using Joy UI in a Material UI project. Everything was working fine before the version 5.11.12 of Material UI and 5.0.0-alpha.70 of Joy UI.

Your environment 🌎

npx @mui/envinfo

Tested on Chrome 110.0.5481.177

  System:
    OS: macOS 13.1
  Binaries:
    Node: 16.17.1 - ~/.nvm/versions/node/v16.17.1/bin/node
    Yarn: 1.22.19 - /opt/homebrew/bin/yarn
    npm: 8.15.0 - ~/.nvm/versions/node/v16.17.1/bin/npm
  Browsers:
    Chrome: 110.0.5481.177
    Edge: Not Found
    Firefox: 110.0.1
    Safari: 16.2
  npmPackages:
    @emotion/react: 11.10.6 => 11.10.6 
    @emotion/styled: 11.10.6 => 11.10.6 
    @mui/base:  5.0.0-alpha.120 
    @mui/core-downloads-tracker:  5.11.12 
    @mui/icons-material: ^5.11.9 => 5.11.11 
    @mui/joy: ^5.0.0-alpha.68 => 5.0.0-alpha.70 
    @mui/material: ^5.11.10 => 5.11.12 
    @mui/private-theming:  5.11.12 
    @mui/styled-engine:  5.11.11 
    @mui/system:  5.11.12 
    @mui/types:  7.2.3 
    @mui/utils:  5.11.12 
    @mui/x-data-grid:  5.17.26 
    @mui/x-data-grid-pro: ^5.17.16 => 5.17.26 
    @mui/x-date-pickers:  5.0.0 
    @mui/x-date-pickers-pro:  5.0.0 
    @mui/x-license-pro:  5.17.12 
    @types/react: ^18.0.0 => 18.0.28 
    react: ^18.0.2 => 18.2.0 
    react-dom: ^18.0.2 => 18.2.0 
    typescript: ^4.1.2 => 4.9.5 

[hbjORbj]

The app throws this kind of error: "Cannot read properties of undefined (reading '[property]')".

I cannot reproduce this issue. Can you please take a screen recording?

[egazarian]

Yes, sure.

Enregistrement.de.l.ecran.2023-03-07.a.15.05.24.mov

[egazarian]

I tested on firefox 110.0.1 and the app throws another error: "TypeError: theme.vars.fontSize is undefined"

[egazarian]

Maybe it's related to this #36282 (comment)

[hbjORbj]

#36282 was released in 5.0.0-alpha.70, and the issue you reported still happens with lower versions, so I think this is a different issue.

[egazarian]

Ok, that makes sense.

[hbjORbj]

It is a bug indeed.

Here are working Codesandboxes: (1) https://codesandbox.io/s/material-ui-feat-joy-ui-1jkvm9?file=/demo.tsx and (2) https://codesandbox.io/s/joy-ui-feat-material-ui-zhcprk?file=/demo.tsx

I will create a PR soon. Thanks again for the report.

[egazarian]

Thanks for the fix 🙇

[tombombadilom]

So quick ! Everything alright now, you are great !!!