An ESLint plugin to identify and fix breaking changes when upgrading React 18 to React 19

You'll first need to install ESLint:

$ npm i eslint --save-dev

Next, install eslint-plugin-react-19-upgrade:

$ npm install eslint-plugin-react-19-upgrade --save-dev

Add react-19-upgrade to the plugins section of your .eslintrc configuration file. You can omit the eslint-plugin- prefix:

{
  "plugins": ["react-19-upgrade"]
}

Then configure the rules you want to use under the rules section.

{
  "rules": {
    "react-19-upgrade/no-default-props": "error",
    "react-19-upgrade/no-prop-types": "warn",
    "react-19-upgrade/no-legacy-context": "error",
    "react-19-upgrade/no-string-refs": "error",
    "react-19-upgrade/no-factories": "error"
  }
}

• no-default-props: Move defaultProps to default parameters in the destructured props. Fixable by ESLint.
• no-prop-types: Avoid using propTypes as they are now ignored in React 19.
• no-legacy-context: Disallow the use of legacy context APIs in React class components.
• no-string-refs: Disallow the use of string refs in React components.
• no-factories: Disallow module pattern factories and React.createFactory.