[SB-1175] Migration: Main.js/Preview default exports

[shilman]

Is your feature request related to a problem? Please describe

We are moving to default exports for main.js and preview.js configuration. This is friendlier for TypeScript.

Before:

module.exports = { stories: [...] }
//OR
export const stories = [...]

After:

export default {
  stories: [...]
}

const config = {
  addons: ['docs']
} satisfies Config;

const preview = {
  
} satisfies Preview;

export default preview;

Describe the solution you'd like

Default exports are already supported in SB7, but now we need to get users upgraded:

• Add deprecation warnings for any other format
• Provide an automigration that upgrades users to default exports
  • JS users
  • TS users

Describe alternatives you've considered

No response

Are you able to assist to bring the feature to reality?

no

Additional context

No response

_{From SyncLinear.com | SB-1175}

[yannbf]

@shilman are we expecting users to use as or satisfies in export default? I believe the type-safest solution would be:

const config: StorybookConfig = {
  stories: [...]
}

export default config

Also, is this for preview.js as well? I don't believe we have a type for that

[shilman]

I think what you wrote is correct. For preview.js, it's up for discussion. I think @kasperpeulen wanted it but maybe we can split this into two tickets & do the other one once he gets back

[yannbf]

That sounds much better. We need a proper typing system that will also address addons, parameters, globalTypes, etc

[IanVS]

Have you considered using a helper like vite's defineConfig? https://vitejs.dev/config/#config-intellisense?

[shilman]

ZOMG!! I just released https://github.com/storybookjs/storybook/releases/tag/v7.0.0-beta.38 containing PR #20797 that references this issue. Upgrade today to the @next NPM tag to try it out!

npx sb@next upgrade --prerelease

Closing this issue. Please re-open if you think there's still more to do.