Textarea: Add minHeight and maxHeight as props

[TylerJDev]

Closes https://github.com/github/primer/issues/5296

Adds new props minHeight and maxHeight to the Textarea. This allows you to customize the min/max height of the textarea directly.

Changelog

New

• Added minHeight and maxHeight props to Textarea

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; if selected, include a brief description as to why

Testing & Reviewing

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Storybook)
• Changes are SSR compatible
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge
• (GitHub staff only) Integration tests pass at github/github (Learn more about how to run integration tests)

[changeset-bot]

🦋 Changeset detected

Latest commit: 5777c3b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/react	Minor

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[github-actions]

👋 Hi, this pull request contains changes to the source code that github/github depends on. If you are GitHub staff, we recommend testing these changes with github/github using the integration workflow. Thanks!

[Copilot]

Pull Request Overview

This PR adds support for customizing the textarea’s height by introducing minHeight and maxHeight props.

• Adds minHeight and maxHeight to the TextareaProps and applies them via inline styles
• Updates tests and stories to cover the new props
• Documents the new props and includes a changeset for a minor release

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/react/src/Textarea/Textarea.tsx	Added minHeight/maxHeight props and style handling
packages/react/src/Textarea/Textarea.test.tsx	Added tests for minHeight and maxHeight styles
packages/react/src/Textarea/Textarea.features.stories.tsx	Added feature stories showcasing the new props
packages/react/src/Textarea/Textarea.docs.json	Documented the new props in the generated JSON docs
.changeset/social-ants-bow.md	Created changeset for a minor release

Comments suppressed due to low confidence (1)

packages/react/src/Textarea/Textarea.tsx:40

• Consider allowing both string and number types for CSS flexibility (e.g. '2rem', '50%') by typing minHeight/maxHeight as CSSProperties['minHeight'] instead of number only.

minHeight?: number

[Copilot]

[nitpick] User-supplied style props may override these height settings; consider merging existing rest.style first (e.g. style={{ ...rest.style, minHeight, maxHeight }}) to avoid unintentional overrides.

Suggested change

	style={{
	style={{
	...rest.style,

[francinelucca]

should we use small/medium/large/xlarge instead? 🤔 CC: @langermank

[TylerJDev]

I noticed that we directly expose style on the textarea, as the ...rest allows for pretty much anything (style included). I'm wondering if this change is still worth it?

e.g. we could do <Textarea style={{minHeight: 100}} /> to get the same effect. Curious what y'all think

(cc: @langermank, @francinelucca)

[francinelucca]

if we're not going to "Standardize" the sizes then I feel better with opting for just the existing style prop for these type of changes, i.e. no changes needed. But will defer to @langermank for final call