#require-default-props

#Configuration

import { defineConfig, reactPlugin } from '@rslint/core';

export default defineConfig([
  reactPlugin.configs.recommended,
  {
    rules: {
      'react/require-default-props': 'error',
    },
  },
]);

#Rule Details

Require a default value for every optional component prop. The rule checks runtime propTypes declarations and locally declared TypeScript prop types.

Examples of incorrect code:

function Greeting({ name }) {
  return <h1>Hello, {name}</h1>;
}
Greeting.propTypes = { name: PropTypes.string };

Examples of correct code:

function Greeting({ name }) {
  return <h1>Hello, {name}</h1>;
}
Greeting.propTypes = { name: PropTypes.string };
Greeting.defaultProps = { name: 'world' };

Required props do not need defaults. An external defaultProps assignment that cannot be resolved, or a spread in the defaults object, skips the component to avoid reporting defaults supplied elsewhere.

#Options

#Default arguments

For function components using default parameters, configure:

{ "react/require-default-props": ["error", { "functions": "defaultArguments" }] }

Examples of incorrect code with this option:

function Greeting({ name }: { name?: string }) {
  return <h1>Hello, {name}</h1>;
}

Examples of correct code with this option:

function Greeting({ name = 'world' }: { name?: string }) {
  return <h1>Hello, {name}</h1>;
}

This mode reports defaultProps on function components and requires optional props to have defaults in the destructured parameter. It also reports defaults for required destructured props, independently of forbidDefaultForRequired.

#Required props

{ "react/require-default-props": ["error", { "forbidDefaultForRequired": true }] }

With this option, a prop declared as PropTypes.string.isRequired must not also appear in defaultProps.

#When Not To Use It

Disable this rule when optional props may intentionally remain undefined.

#Differences from ESLint

• React.memo and React.forwardRef components honor functions: "ignore" and "defaultArguments"; eslint-plugin-react v7.37.5 treats their wrappers separately.
• Optional props named toString, constructor, or other inherited object names need explicit defaults. Upstream can mistake inherited properties for defaults.
• Inline class props types and props types declared inside functions are checked; upstream can skip these optional props.
• Reading Component.defaultProps does not suppress missing-default diagnostics; upstream can treat that read as an unresolved default declaration.
• Multiple component values assigned to the same binding produce one diagnostic per prop contract. A later component is still checked after a non-component value.
• Components nested in an object assigned to a member retain their complete external path; upstream can miss declarations such as ns.registry.C.propTypes.

#Original Documentation

• eslint-plugin-react: require-default-props
• Source code