react19-source-patterns
Reference for React 19 source-file migration patterns, including API changes, ref handling, and context updates.
Best use case
react19-source-patterns is best used when you need a repeatable AI agent workflow instead of a one-off prompt.
Reference for React 19 source-file migration patterns, including API changes, ref handling, and context updates.
Teams using react19-source-patterns should expect a more consistent output, faster repeated execution, less prompt rewriting.
When to use this skill
- You want a reusable workflow that can be run more than once with consistent structure.
When not to use this skill
- You only need a quick one-off answer and do not need a reusable workflow.
- You cannot install or maintain the underlying files, dependencies, or repository context.
Installation
Claude Code / Cursor / Codex
Manual Installation
- Download SKILL.md from GitHub
- Place it in
.claude/skills/react19-source-patterns/SKILL.mdinside your project - Restart your AI agent — it will auto-discover the skill
How react19-source-patterns Compares
| Feature / Agent | react19-source-patterns | Standard Approach |
|---|---|---|
| Platform Support | Not specified | Limited / Varies |
| Context Awareness | High | Baseline |
| Installation Complexity | Unknown | N/A |
Frequently Asked Questions
What does this skill do?
Reference for React 19 source-file migration patterns, including API changes, ref handling, and context updates.
Where can I find the source code?
You can find the source code on GitHub using the link provided at the top of the page.
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SKILL.md Source
# React 19 Source Migration Patterns
Reference for every source-file migration required for React 19.
## Quick Reference Table
| Pattern | Action | Reference |
|---|---|---|
| `ReactDOM.render(...)` | → `createRoot().render()` | See references/api-migrations.md |
| `ReactDOM.hydrate(...)` | → `hydrateRoot(...)` | See references/api-migrations.md |
| `unmountComponentAtNode` | → `root.unmount()` | Inline fix |
| `ReactDOM.findDOMNode` | → direct ref | Inline fix |
| `forwardRef(...)` wrapper | → ref as direct prop | See references/api-migrations.md |
| `Component.defaultProps = {}` | → ES6 default params | See references/api-migrations.md |
| `useRef()` no arg | → `useRef(null)` | Inline fix add `null` |
| Legacy Context | → `createContext` | [→ api-migrations.md#legacy-context](references/api-migrations.md#legacy-context) |
| String refs `this.refs.x` | → `createRef()` | [→ api-migrations.md#string-refs](references/api-migrations.md#string-refs) |
| `import React from 'react'` (unused) | Remove | Only if no `React.` usage in file |
## PropTypes Rule
Do **not** remove `.propTypes` assignments. The `prop-types` package still works as a standalone validator. React 19 only removes the built-in runtime checking from the React package the package itself remains valid.
Add this comment above any `.propTypes` block:
```jsx
// NOTE: React 19 no longer runs propTypes validation at runtime.
// PropTypes kept for documentation and IDE tooling only.
```
## Read the Reference
For full before/after code for each migration, read **`references/api-migrations.md`**. It contains the complete patterns including edge cases for `forwardRef` with `useImperativeHandle`, `defaultProps` null vs undefined behavior, and legacy context provider/consumer cross-file migrations.Related Skills
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