Skip to content

Docs: Add FAQ section for extensionless imports #33202

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
yannbf merged 2 commits into from
Nov 28, 2025
Merged

Docs: Add FAQ section for extensionless imports #33202

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
829d445
Docs: Add FAQ section for extensionless imports
valentinpalkovic Nov 27, 2025
a7c6398
Update deprecation message for extensionless imports with additional …
valentinpalkovic Nov 27, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 0 additions & 5 deletions code/core/src/bin/loader.test.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -34,11 +34,6 @@ describe('loader', () => {
expect(deprecate).toHaveBeenCalledWith(
expect.stringContaining('One or more extensionless imports detected: "./utils"')
);
expect(deprecate).toHaveBeenCalledWith(
expect.stringContaining(
'For maximum compatibility, you should add an explicit file extension'
)
);
});

it('should resolve extensionless import to .js extension when file exists', () => {
Expand Down
7 changes: 5 additions & 2 deletions code/core/src/bin/loader.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -37,8 +37,11 @@ export function resolveWithExtension(importPath: string, currentFilePath: string
return importPath;
}

deprecate(dedent`One or more extensionless imports detected: "${importPath}" in file "${currentFilePath}".
For maximum compatibility, you should add an explicit file extension to this import. Storybook will attempt to resolve it automatically, but this may change in the future. If adding the extension results in an error from TypeScript, we recommend setting moduleResolution to "bundler" in tsconfig.json or alternatively look into the allowImportingTsExtensions option.`);
deprecate(dedent`
One or more extensionless imports detected: "${importPath}" in file "${currentFilePath}".
For more information on how to resolve the issue:
https://storybook.js.org/docs/faq#extensionless-imports-in-storybookmaints-and-required-ts-extensions
`);
Comment on lines +40 to +44
Copy link
Contributor

@coderabbitai coderabbitai bot Nov 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue | 🟡 Minor

Minor formatting issue: trailing space on line 42.

The deprecation message update looks good—shortening it to reference external documentation is a solid practice. However, line 42 has a trailing space after the colon.

Apply this diff to remove the trailing space:

   deprecate(dedent`
     One or more extensionless imports detected: "${importPath}" in file "${currentFilePath}".
-    For more information on how to resolve the issue: 
+    For more information on how to resolve the issue:
     https://storybook.js.org/docs/faq#extensionless-imports-in-storybookmaints-and-required-ts-extensions
   `);
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
deprecate(dedent`
One or more extensionless imports detected: "${importPath}" in file "${currentFilePath}".
For more information on how to resolve the issue:
https://storybook.js.org/docs/faq#extensionless-imports-in-storybookmaints-and-required-ts-extensions
`);
deprecate(dedent`
One or more extensionless imports detected: "${importPath}" in file "${currentFilePath}".
For more information on how to resolve the issue:
https://storybook.js.org/docs/faq#extensionless-imports-in-storybookmaints-and-required-ts-extensions
`);
🤖 Prompt for AI Agents 
In code/core/src/bin/loader.ts around lines 40 to 44, the deprecation message
contains an extra trailing space after the colon on line 42; remove that
trailing space so the dedent string URL line ends immediately after the colon
(no extra whitespace), and ensure the multiline string has no other unintended
trailing spaces.


// Resolve the import path relative to the current file
const currentDir = path.dirname(currentFilePath);
Expand Down
33 changes: 33 additions & 0 deletions docs/faq.mdx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -101,6 +101,39 @@ To fix this, you can wrap the package name inside your Storybook configuration f

{/* prettier-ignore-end */}

## Extensionless imports in Storybook main config

When upgrading or running Storybook, you may see warnings about extensionless relative imports in `.storybook/main.<js|ts>` (for example: `import sharedMain from '../main'`).
Storybook requires explicit extensions in config imports to avoid this deprecation warning.

To fix the issue, just make sure to include the extension of the file (TypeScript or Javascript) you're importing:

```ts title=".storybook/main.<js|ts>"
// Change from this 👇
import sharedMain from '../main';

// To this 👇
import sharedMain from '../main.js'; // or .ts
```

### For TypeScript users (`.storybook/main.ts`)
You will also need to configure TypeScript so these imports type-check without emitting JavaScript:

```json title=".storybook/tsconfig.json"
{
"extends": "<path-to-your-main-tsconfig>",
"compilerOptions": {
"moduleResolution": "bundler",
"allowImportingTsExtensions": true,
"noEmit": true
}
}
```

<Callout variant="info">
It is advisable to add a `.storybook/tsconfig.json` file so that you apply changes only to Storybook config files, and not your entire project.
</Callout>

## How do I setup the new React Context Root API with Storybook?

If your installed React Version equals or is higher than 18.0.0, the new React Root API is automatically used and the newest React [concurrent features](https://reactjs.org/docs/concurrent-mode-intro.html) can be used.
Expand Down