beta: React 18 + 19 compatibility

[dreamwasp]

Overview

Upgrades the Gamut monorepo for React 19 while keeping React 18 in the supported peer range for consumers. This includes:

• Workspace dependencies on React 19 (react, react-dom, react-test-renderer) and aligned Yarn resolutions.
• Peer dependency updates on published packages (e.g. @codecademy/gamut) so apps can use React 18.3 or 19.
• react-hook-form upgrade and follow-on fixes in Connected Form / Grid Form.
• React 19–oriented ref handling (notably Popover / PopoverContainer and related floating UI) and small utilities (isNullish / isDefined) where strict equality is required.
• Tooling updates (ESLint, TypeScript-ESLint, Testing Library, Jest config tweaks) and eslint-plugin-gamut rule/test updates.

PR Checklist

• Related to designs:
• Related to JIRA ticket: GMT-1473
• Version plan added/updated (or not needed)
• I have run this code to verify it works
• This PR includes unit tests for the code change
• This PR includes testing instructions tests for the code change
• [tbd] The alpha package of this PR is passing end-to-end tests in all relevant Codecademy repositories

Testing Instructions

Component / area	Location	What to verify
Popover / positioning	Atoms → PopoverContainer	Open/close, alignment controls, scroll/resize; repeat with RTL on.
Tooltips / floating tips	Molecules → Tips → ToolTip (and other Tip stories as needed)	Open states, anchor behavior.
Modal / focus	Molecules → Modals → Modal	Open, focus trap, close; Dark mode.
Menu	Molecules → Menu	Keyboard nav, disabled items if covered by stories.
Select	Atoms → FormInputs → SelectDropdown	Default, multi-select, and searchable examples if present.
Forms (RHF)	Organisms → ConnectedForm → ConnectedForm / ConnectedFormGroup / ConnectedFormInputs	Submit/validation flows still work.
Grid Form	Organisms → GridForm (e.g. Usage, States, Layout)	Field groups and validation.

Accessibility: On a subset of the above (PopoverContainer, Modal, Menu, SelectDropdown, ConnectedForm), run VoiceOver : focus order, labels, and escape to dismiss.

PR Previews

mono on 18
mono on 19
monolith on 18

[nx-cloud]

View your CI Pipeline Execution ↗ for commit 71b5d00

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☁️ Nx Cloud last updated this comment at 2026-04-15 21:15:52 UTC

[codecov]

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[codecademydev]

📬 Published Alpha Packages:

Package	Version	npm	Diff
@codecademy/gamut	68.2.3-alpha.cc966e.0	npm	diff
@codecademy/gamut-icons	9.57.3-alpha.cc966e.0	npm	diff
@codecademy/gamut-illustrations	0.58.10-alpha.cc966e.0	npm	diff
@codecademy/gamut-kit	0.6.593-alpha.cc966e.0	npm	diff
@codecademy/gamut-patterns	0.10.29-alpha.cc966e.0	npm	diff
@codecademy/gamut-styles	17.13.2-alpha.cc966e.0	npm	diff
@codecademy/gamut-tests	5.3.4-alpha.cc966e.0	npm	diff
@codecademy/variance	0.26.2-alpha.cc966e.0	npm	diff
eslint-plugin-gamut	2.4.4-alpha.cc966e.0	npm	diff

[github-actions]

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