Core: Extract React CSF tools into Core

[huang-julien]

What I did

This PR moves the CSF-interpretation helpers used by React's component manifest ( for story snippet generation) into a new csf-tools/story-shape module in core, so other frameworks can reuse them instead of re-implementing the same AST logic.

• normalizeStoryDeclaration: resolves a story export across CSF versions (CSF2 Template.bind({}), CSF3 objects, satisfies/as, CSF4 factories) into a classified result: { type: 'config' | 'fn' | 'emptyConfig', path }
• args helpers: extract and merge meta/story args records with CSF precedence
• collectImportBindings: map local identifiers to their import sources (skipping type-only imports)
• extractStoryJSDocInfo :story description/summary from JSDoc tag

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

---

Caution

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts

• Declare whether manual QA will be needed for this PR during the next release, through qa:needed or qa:skip

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook publish.yml --field pr=<PR_NUMBER>

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 5e46d13e-2b7d-4adc-a5b2-ea299cb082f6

📥 Commits

Reviewing files that changed from the base of the PR and between 295d826 and b3f8b20.

📒 Files selected for processing (5)

• code/core/src/csf-tools/story-shape/args.test.ts
• code/core/src/csf-tools/story-shape/imports.test.ts
• code/core/src/csf-tools/story-shape/jsdoc.test.ts
• code/core/src/csf-tools/story-shape/normalize-story.test.ts
• code/core/src/csf-tools/story-shape/utils.test.ts

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Walkthrough

Changes

CSF story-shape tooling

Layer / File(s)	Summary
Shared AST utilities code/core/src/csf-tools/story-shape/*, code/core/src/csf-tools/index.ts	Adds shared utilities for CSF arguments, runtime imports, JSDoc metadata, object keys, identifier initializers, and metadata paths. Adds Vitest coverage.
Story declaration normalization code/core/src/csf-tools/story-shape/normalize-story.ts, code/core/src/csf-tools/story-shape/normalize-story.test.ts	Normalizes object stories, function stories, bound templates, factory calls, and TypeScript-wrapped declarations.
Component manifest integration code/renderers/react/src/componentManifest/*	Uses the shared utilities for story normalization, argument merging, import collection, and JSDoc extraction. Removes duplicate local implementations.

Sequence Diagram(s)

sequenceDiagram
  participant ComponentManifest
  participant normalizeStoryDeclaration
  participant metaObjectPath
  participant collectImportBindings
  ComponentManifest->>normalizeStoryDeclaration: normalize story declaration
  ComponentManifest->>metaObjectPath: resolve CSF metadata object
  ComponentManifest->>collectImportBindings: collect runtime import bindings
  normalizeStoryDeclaration-->>ComponentManifest: return story shape
  metaObjectPath-->>ComponentManifest: return metadata path
  collectImportBindings-->>ComponentManifest: return import map

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Possibly related PRs

• storybookjs/storybook#35623: Both changes use shared CSF-tools JSDoc utilities in the React component manifest.
• storybookjs/storybook#35733: Both changes use centralized CSF AST utilities for imports and story structure.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@code/core/src/csf-tools/story-shape/utils.ts`:
- Around line 6-7: Update keyOf to return null when the ObjectProperty key is
computed, including computed identifier keys such as {[render]: value}; only
return identifier names for non-computed keys. Preserve the existing support for
non-computed string literal keys such as {"render": value}.

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---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 90be1f34-b097-4652-aab7-237e280d2641

📥 Commits

Reviewing files that changed from the base of the PR and between 086c98e and 6e44c3c.

📒 Files selected for processing (10)

• code/core/src/csf-tools/index.ts
• code/core/src/csf-tools/story-shape/args.ts
• code/core/src/csf-tools/story-shape/imports.ts
• code/core/src/csf-tools/story-shape/index.ts
• code/core/src/csf-tools/story-shape/jsdoc.ts
• code/core/src/csf-tools/story-shape/normalize-story.ts
• code/core/src/csf-tools/story-shape/utils.ts
• code/renderers/react/src/componentManifest/generateCodeSnippet.ts
• code/renderers/react/src/componentManifest/getComponentImports.ts
• code/renderers/react/src/componentManifest/resolveComponents.ts

[valentinpalkovic]

I think some of the helpers deserve some unit tests :)

[storybook-app-bot]

Package Benchmarks

^{Commit: b4323fb, ran on 6 August 2026 at 13:35:16 UTC}

The following packages have significant changes to their size or dependencies:

storybook

	Before	After	Difference
Dependency count	73	73	0
Self size	21.45 MB	21.46 MB	🚨 +11 KB 🚨
Dependency size	31.21 MB	31.21 MB	0 B
Bundle Size Analyzer	Link	Link

@storybook/cli

	Before	After	Difference
Dependency count	205	205	0
Self size	831 KB	831 KB	🎉 -84 B 🎉
Dependency size	86.14 MB	86.15 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/codemod

	Before	After	Difference
Dependency count	198	198	0
Self size	32 KB	32 KB	0 B
Dependency size	84.62 MB	84.63 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

create-storybook

	Before	After	Difference
Dependency count	74	74	0
Self size	1.09 MB	1.09 MB	0 B
Dependency size	52.66 MB	52.67 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	node	node

[ndelangen]

@huang-julien This broke windows, I fixed it here:
#35800