- Adds React 18 and 19 migration orchestration plugins
- Introduces comprehensive upgrade toolkits for migrating legacy React 16/17 and 18 codebases to React 18.3.1 and 19, respectively. Each plugin bundles specialized agents and skills for exhaustive audit, dependency management, class/component API migration, test suite transformation, and batching regression fixes.
- The React 18 toolkit targets class-component-heavy apps, ensures safe lifecycle and context transitions, resolves dependency blockers, and fully automates test migrations including Enzyme removal. The React 19 toolkit addresses breaking changes such as removal of legacy APIs, defaultProps on function components, and forwardRef, while enforcing a gated, memory-resumable migration pipeline.
- Both plugins update documentation, plugin registries, and skill references to support reliable, repeatable enterprise-scale React migrations.
React 18.3.1 and React 19 dependency compatibility matrix.
React Dependency Compatibility Matrix
Minimum versions required for React 18.3.1 and React 19 compatibility.
Use this skill whenever checking whether a dependency supports a target React version, resolving peer dependency conflicts, deciding whether to upgrade or use legacy-peer-deps, or assessing the risk of a react-router v5 to v6 migration.
Review this matrix before running npm install during a React upgrade and before accepting an npm dependency conflict resolution, especially where concurrent mode compatibility may be affected.
Core Upgrade Targets
Package
React 17 (current)
React 18.3.1 (min)
React 19 (min)
Notes
react
17.x
18.3.1
19.0.0
Pin exactly to 18.3.1 for the R18 orchestra
react-dom
17.x
18.3.1
19.0.0
Must match react version exactly
Testing Libraries
Package
React 18 Min
React 19 Min
Notes
@testing-library/react
14.0.0
16.0.0
RTL 13 uses ReactDOM.render internally - broken in R18
@testing-library/jest-dom
6.0.0
6.0.0
v5 works but v6 has React 18 matcher updates
@testing-library/user-event
14.0.0
14.0.0
v13 is sync, v14 is async - API change required
jest
27.x
27.x
jest 27+ with jsdom 16+ for React 18
jest-environment-jsdom
27.x
27.x
Must match jest version
Apollo Client
Package
React 18 Min
React 19 Min
Notes
@apollo/client
3.8.0
3.11.0
3.8 adds useSyncExternalStore for concurrent mode
graphql
15.x
16.x
Apollo 3.8+ peer requires graphql 15 or 16
Read references/apollo-details.md for concurrent mode issues and MockedProvider changes.
Emotion
Package
React 18 Min
React 19 Min
Notes
@emotion/react
11.10.0
11.13.0
11.10 adds React 18 concurrent mode support
@emotion/styled
11.10.0
11.13.0
Must match @emotion/react version
@emotion/cache
11.10.0
11.13.0
If used directly
React Router
Package
React 18 Min
React 19 Min
Notes
react-router-dom
v6.0.0
v6.8.0
v5 → v6 is a breaking migration - see details below
react-router-dom v5
5.3.4 (workaround)
❌ Not supported
See legacy peer deps note
react-router v5 → v6 is a SEPARATE migration sprint. Read references/router-migration.md.
Redux
Package
React 18 Min
React 19 Min
Notes
react-redux
8.0.0
9.0.0
v7 works on R18 legacy root only - breaks on concurrent mode
redux
4.x
5.x
Redux itself is framework-agnostic - react-redux version matters
@reduxjs/toolkit
1.9.0
2.0.0
RTK 1.9 tested against React 18
Other Common Packages
Package
React 18 Min
React 19 Min
Notes
react-query / @tanstack/react-query
4.0.0
5.0.0
v3 doesn't support concurrent mode
react-hook-form
7.0.0
7.43.0
v6 has concurrent mode issues
formik
2.2.9
2.4.0
v2.2.9 patched for React 18
react-select
5.0.0
5.8.0
v4 has peer dep conflicts with R18
react-datepicker
4.8.0
6.0.0
v4.8+ added React 18 support
react-dnd
16.0.0
16.0.0
v15 and below have R18 concurrent mode issues
prop-types
any
any
Standalone - unaffected by React version
Conflict Resolution Decision Tree
npm ls shows peer conflict for package X
│
▼
Does package X have a version that supports React 18?
YES → npm install X@[min-compatible-version]
NO ↓
│
Is the package critical to the app?
YES → check GitHub issues for React 18 branch/fork
→ check if maintainer has a PR open
→ last resort: --legacy-peer-deps (document why)
NO → consider removing the package
--legacy-peer-deps Rules
Only use --legacy-peer-deps when:
The package has no React 18 compatible release
The package is actively maintained (not abandoned)
The conflict is only a peer dep declaration mismatch (not actual API incompatibility)
Document every --legacy-peer-deps usage in a comment at the top of package.json or in a MIGRATION.md file explaining why it was necessary.