Error in @mui/system: Modules ./typography and others have no exported member default

[morozow]

Steps to reproduce

Link to live example: local dev as there's no TS completion to build live phase

Description:

1. When attempting to build a TypeScript project that imports from @mui/system, the TypeScript compiler throws the following error:

node_modules/@mui/system/typography/index.d.ts:1:10 - error TS2305: Module '"./typography"' has no exported member 'default'.

1 export { default } from './typography';

Steps to Reproduce

1. Install the latest version of @mui/system via yarn or follow a Default Installation - Material UI
2. Set up a TypeScript project that imports @mui/system.
3. Run the TypeScript compiler.

The same issue with:

• Module ./borders...
• Module ./cssGrid...
• Module ./display...
• Module ./flexbox...
• Module ./palette...
• Module ./positions...
• Module ./shadows...
• Module ./sizing...
• Module ./spacing...
• Module ./style...
• Module ./typography...

Current behavior

The TypeScript compiler fails with a TS2305 error indicating that index.d.ts incorrectly attempts to export a non-existent default member from ./typography.

 error TS2305: Module '"./typography"' has no exported member 'default'.

1 export { default } from './typography';

Expected behavior

The TypeScript compiler should complete without errors, allowing for the proper usage of the @mui/system package components.

Context

Additional Context

• Node.js version: v20.9.0
• yarn version: 1.22.19
• TypeScript version: 5.6.2
• MUI System version: 6.0.2

Your environment

npx @mui/envinfo

  System:
    OS: macOS 14.1.1
  Binaries:
    Node: 20.9.0 - /usr/local/bin/node
    npm: 10.2.4 - /usr/local/bin/npm
    pnpm: Not Found
  Browsers:
    Chrome: 128.0.6613.120
    Edge: Not Found
    Safari: 17.1
  npmPackages:
    @emotion/react: ^11.13.3 => 11.13.3 
    @emotion/styled: ^11.13.0 => 11.13.0 
    @mui/core-downloads-tracker:  6.0.2 
    @mui/envinfo: ^2.0.25 => 2.0.25 
    @mui/icons-material: ^6.0.2 => 6.0.2 
    @mui/material: ^6.0.2 => 6.0.2 
    @mui/private-theming:  6.0.2 
    @mui/styled-engine:  6.0.2 
    @mui/styles: ^6.0.2 => 6.0.2 
    @mui/system:  6.0.2 
    @mui/types:  7.2.16 
    @mui/utils:  6.0.2 
    @mui/x-date-pickers: ^7.16.0 => 7.16.0 
    @mui/x-internals:  7.16.0 
    @types/react: ^18.3.5 => 18.3.5 
    react: ^18.3.1 => 18.3.1 
    react-dom: ^18.3.1 => 18.3.1 
    typescript: ^5.6.2 => 5.6.2 

Search keywords: error, types, d.ts

[morozow]

Nitpick: If anyone encounters this issue, here is a quick fix for Unix systems using Yarn post-install:

#!/bin/bash
cd ./

find . -type f -name "*.d.ts" -exec sed -i'' -e 's#export = dayjs;*#export default dayjs;#g' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/borders'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/cssGrid'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/display'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/flexbox'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/palette'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/positions'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/sizing'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/spacing'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/style'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e '/export { default } from '\''\.\/typography'\'';/d' {} +
find . -type f -name "index.d.ts" -exec sed -i'' -e 's#export { default } from '\''\.\/shadows'\'';*#export * from '\''\.\/shadows'\'';#g' {} +

Smth like this into package.json:

...
"scripts": {
    "postinstall": "bash ./bin/post.install.sh",
}
...

That works also for a new age "@mui/x-date-pickers": "^7.16.0",

[siriwatknp]

Are you using @mui/system directly? Usually, @mui/system is not required to be installed explicitly if you use Material UI (it's already a dependency)

If you need more help, please provide a CodeSandbox or a repo that we can take a look.

[morozow]

No, I don’t directly use @mui/system. Upon reviewing my package.json, the only dependencies listed are "@mui/icons-material": "^6.0.2", "@mui/material": "^6.0.2", "@mui/styles": "^6.0.2", and "@mui/x-date-pickers": "^7.16.0", with "@mui/envinfo": "^2.0.25" included in devDependencies. It appears that @mui/envinfo aggregates all dependencies independently of package.json. Therefore, the foregoing solution is currently the only fix from my local perspective. Any suggestions? Following a GitHub implementation, it indeed looks like the default export is missing. What could be the reason for this export?

Details:

• index.d.ts - https://github.com/mui/material-ui/blob/v6.0.2/packages/mui-system/src/typography/index.ts#L1
  • export { default } from './typography';
• ./typopgraphy.d.ts - https://github.com/mui/material-ui/blob/v6.0.2/packages/mui-system/src/typography/typography.d.ts
  • no export default

Comparison of suitable imports:

• index.d.ts - https://github.com/mui/material-ui/blob/v6.0.2/packages/mui-system/src/merge/index.ts#L1
  • export { default } from './merge';
• ./merge.d.ts - https://github.com/mui/material-ui/blob/v6.0.2/packages/mui-system/src/merge/merge.d.ts#L1
  • export default function merge(acc: object, item: object): object;
  • export default exists

Nitpick: object type may not be the most suitable here. Consider using unknown or any other generic type that more accurately represents the value

[morozow]

Here are my 2 cents on automating deployment while the above issue remains unresolved: #43700 (comment)

[morozow]

This Pull Request eliminates undefined exports: #43702

Please review it and let me know if there are any additional contributions or changes needed.

Additional note: currently in dev phase as vita has an exception while built

[morozow]

The problem has been fixed by updating the documentation: #43747

[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.

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