feat(ui-components): add Signature and FunctionSignature components

[canerakdas]

Description

Adds new Signature and FunctionSignature components for rendering API function signatures with support for nested parameters, return types, and optional attributes.

Ref: nodejs/doc-kit#587
Figma: https://www.figma.com/design/a10cjjw3MzvRQMPT9FP3xz/Node.js?node-id=6382-1517&t=T63PRMdf9tzlCrww-0

Validation

Related Issues

Related to nodejs/doc-kit#587

Check List

• I have read the Contributing Guidelines and made commit messages that follow the guideline.
• I have run pnpm format to ensure the code follows the style guide.
• I have run pnpm test to check if all tests are passing.
• I have run pnpm build to check if the website builds without errors.
• I've covered new added functionality with unit tests if necessary.

[vercel]

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[github-actions]

👋 Codeowner Review Request

The following codeowners have been identified for the changed files:

Team reviewers: @nodejs/nodejs-website

Please review the changes when you have a chance. Thank you! 🙏

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.09%. Comparing base (8ac227f) to head (988a489).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8667      +/-   ##
==========================================
+ Coverage   75.06%   75.09%   +0.02%     
==========================================
  Files         104      104              
  Lines        9161     9161              
  Branches      316      315       -1     
==========================================
+ Hits         6877     6879       +2     
+ Misses       2282     2280       -2     
  Partials        2        2              

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[Copilot]

Pull request overview

Adds new UI components to render API/function signatures (including nested parameters, optional markers, and return sections) for use across Node.js Doc Kit’s UI component library.

Changes:

• Introduces Signature (root/item wrapper) and supporting subcomponents (SignatureRoot, SignatureItem, SignatureHeader) with new styles.
• Adds FunctionSignature container to render a recursive signature tree from structured data.
• Adds Storybook stories for both components and bumps @node-core/ui-components patch version.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/ui-components/src/Containers/FunctionSignature/index.tsx	Adds the FunctionSignature container and recursive renderer for signature items
packages/ui-components/src/Containers/FunctionSignature/index.stories.tsx	Adds Storybook scenarios for nested params, return types, and type-only definitions
packages/ui-components/src/Common/Signature/index.tsx	Adds Signature component that switches between root and item rendering
packages/ui-components/src/Common/Signature/index.stories.tsx	Adds Storybook examples for optional attributes, long names, and nesting
packages/ui-components/src/Common/Signature/SignatureRoot/index.tsx	Adds root wrapper with titled section and aria-labelledby wiring
packages/ui-components/src/Common/Signature/SignatureRoot/index.module.css	Styles the root container and title
packages/ui-components/src/Common/Signature/SignatureItem/index.tsx	Adds item renderer supporting return-kind styling, description, and nested children
packages/ui-components/src/Common/Signature/SignatureItem/index.module.css	Styles items, nested children layout, and return-item presentation
packages/ui-components/src/Common/Signature/SignatureHeader/index.tsx	Adds header rendering for name/type with optional marker and return indicator
packages/ui-components/src/Common/Signature/SignatureHeader/index.module.css	Styles header layout, long-name wrapping, and type/link presentation
packages/ui-components/package.json	Bumps package version to 1.6.1

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[canerakdas]

[ovflowd]

@canerakdas I also noticed there was no Chromatic deployment?

[avivkeller]

Chromatic deployments run on label

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
nodejs-org	Ready	Preview	Feb 28, 2026 5:09pm

[github-actions]

Lighthouse Results

URL	Performance	Accessibility	Best Practices	SEO	Report
/en	🟢 96	🟢 93	🟢 100	🟢 100	🔗
/en/about	🟢 98	🟢 94	🟢 100	🟠 88	🔗
/en/about/previous-releases	🟢 97	🟢 97	🟢 100	🟢 100	🔗
/en/download	🟢 97	🟢 96	🟠 81	🟢 100	🔗
/en/download/archive/current	🟢 99	🟢 97	🟢 100	🟢 100	🔗
/en/blog	🟢 100	🟢 97	🟢 96	🟢 100	🔗

[ovflowd]

SGTM!

[AugustinMauroy]

NOICE I love this component

[avivkeller]

I'll work on moving this into doc-kit after I finish reviewing all the Dependabot PRs