[lab] themeAugmentation type definition is broken in v6.4.0

[nekoya]

Steps to reproduce

Steps:

1. Create a new project, for example npm create vite@latest
2. Set "skipLibCheck": false in your tsconfig
3. Install MUI and @mui/lab
4. Add the line import type {} from "@mui/lab/themeAugmentation";
5. Run tsc, for example npx tsc --noemit --project tsconfig.app.json

Current behavior

Type errors have occurred.

node_modules/@mui/lab/themeAugmentation/overrides.d.ts:1:10 - error TS2724: '"../LoadingButton"' has no exported member named 'LoadingButtonClassKey'. Did you mean 'ButtonClassKey'?

1 import { LoadingButtonClassKey } from '../LoadingButton';
           ~~~~~~~~~~~~~~~~~~~~~

node_modules/@mui/lab/themeAugmentation/props.d.ts:2:10 - error TS2614: Module '"../LoadingButton"' has no exported member 'LoadingButtonProps'. Did you mean to use 'import LoadingButtonProps from "../LoadingButton"' instead?

2 import { LoadingButtonProps } from '../LoadingButton';
           ~~~~~~~~~~~~~~~~~~

Expected behavior

No type errors.

Context

In v6.4.0, the <Button> component supports loading attribute, and <LoadingButton> has been deprecated.

However, themeAugmentation still references deleted types.

• https://github.com/mui/material-ui/blob/v6.4.0/packages/mui-lab/src/themeAugmentation/overrides.d.ts#L1
• https://github.com/mui/material-ui/blob/v6.4.0/packages/mui-lab/src/themeAugmentation/props.d.ts#L2

These types were declared in v6.3.1 and earlier.

• https://github.com/mui/material-ui/blob/v6.3.1/packages/mui-lab/src/LoadingButton/loadingButtonClasses.ts#L25
• https://github.com/mui/material-ui/blob/v6.3.1/packages/mui-lab/src/LoadingButton/LoadingButton.d.ts#L75-L78

In v6.4.0, the definition for <LoadingButton> shares the same definition as Button.

• https://github.com/mui/material-ui/blob/v6.4.0/packages/mui-lab/src/LoadingButton/LoadingButton.d.ts

Thus, type errors have occurred.

Your environment

npx @mui/envinfo

  System:
    OS: macOS 15.2
  Binaries:
    Node: 22.11.0 - ~/.nodebrew/current/bin/node
    npm: 10.9.0 - ~/.nodebrew/current/bin/npm
    pnpm: Not Found
  Browsers:
    Chrome: 131.0.6778.266
    Edge: Not Found
    Safari: 18.2
  npmPackages:
    @emotion/react: 11.14.0 => 11.14.0 
    @emotion/styled: 11.14.0 => 11.14.0 
    @mui/base:  5.0.0-beta.68 
    @mui/core-downloads-tracker:  6.4.0 
    @mui/lab: 6.0.0-beta.23 => 6.0.0-beta.23 
    @mui/material: 6.4.0 => 6.4.0 
    @mui/private-theming:  6.4.0 
    @mui/styled-engine:  6.4.0 
    @mui/system:  6.4.0 
    @mui/types:  7.2.21 
    @mui/utils:  6.4.0 
    @types/react: ^18.3.18 => 18.3.18 
    react: ^18.3.1 => 18.3.1 
    react-dom: ^18.3.1 => 18.3.1 
    typescript: ~5.6.2 => 5.6.3 

Search keywords: lab, themeAugmentation, LoadingButton, type error

[Janpot]

I believe this would be fixed by #45072
You can try out this fix by adding the following resolution:

// ./package.json
"resolutions": {
  "@mui/lab": "https://pkg.csb.dev/mui/material-ui/commit/13459abd/@mui/lab"
}

[github-actions]

This issue has been closed. If you have a similar problem but not exactly the same, please open a new issue.
Now, if you have additional information related to this issue or things that could help future readers, feel free to leave a comment.

Note

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[nekoya]

I confirmed that this is fixed in 6.4.2. Thank you.