static-property-placement.md

Enforces where React component static properties should be positioned (react/static-property-placement)

This rule allows you to enforce where childContextTypes, contextTypes, contextType, defaultProps, displayName, and propTypes are declared in an ES6 class.

Rule Details

By default, this rule will check for and warn about declaring any of the above properties outside of the class body.

The three key options are static public field, static getter, and property assignment.

When static public field is enabled (default)

Examples of incorrect code for this rule:

class MyComponent extends React.Component {
  static get childContextTypes() { /*...*/ }
  static get contextTypes() { /*...*/ }
  static get contextType() { /*...*/ }
  static get displayName() { /*...*/ }
  static get defaultProps() { /*...*/ }
  static get propTypes() { /*...*/ }
}

class MyComponent extends React.Component { /*...*/ }
MyComponent.childContextTypes = { /*...*/ };
MyComponent.contextTypes = { /*...*/ };
MyComponent.contextType = { /*...*/ };
MyComponent.displayName = "Hello";
MyComponent.defaultProps = { /*...*/ };
MyComponent.propTypes = { /*...*/ };

Examples of correct code for this rule:

class MyComponent extends React.Component {
  static childContextTypes = { /*...*/ };
  static contextTypes = { /*...*/ };
  static contextType = { /*...*/ };
  static displayName = "Hello";
  static defaultProps = { /*...*/ };
  static propTypes = { /*...*/ };
}

When static getter is enabled

Examples of incorrect code for this rule:

class MyComponent extends React.Component {
  static childContextTypes = { /*...*/ };
  static contextTypes = { /*...*/ };
  static contextType = { /*...*/ };
  static displayName = "Hello";
  static defaultProps = { /*...*/ };
  static propTypes = { /*...*/ };
}

class MyComponent extends React.Component { /*...*/ }
MyComponent.childContextTypes = { /*...*/ };
MyComponent.contextTypes = { /*...*/ };
MyComponent.contextType = { /*...*/ };
MyComponent.displayName = "Hello";
MyComponent.defaultProps = { /*...*/ };
MyComponent.propTypes = { /*...*/ };

Examples of correct code for this rule:

class MyComponent extends React.Component {
  static get childContextTypes() { /*...*/ }
  static get contextTypes() { /*...*/ }
  static get contextType() { /*...*/ }
  static get displayName() { /*...*/ }
  static get defaultProps() { /*...*/ }
  static get propTypes() { /*...*/ }
}

When property assignment is enabled

Examples of incorrect code for this rule:

class MyComponent extends React.Component {
  static childContextTypes = { /*...*/ };
  static contextTypes = { /*...*/ };
  static contextType = { /*...*/ };
  static displayName = "Hello";
  static defaultProps = { /*...*/ };
  static propTypes = { /*...*/ };
}

class MyComponent extends React.Component {
  static get childContextTypes() { /*...*/ }
  static get contextTypes() { /*...*/ }
  static get contextType() { /*...*/ }
  static get displayName() { /*...*/ }
  static get defaultProps() { /*...*/ }
  static get propTypes() { /*...*/ }
}

Examples of correct code for this rule:

class MyComponent extends React.Component { /*...*/ }
MyComponent.childContextTypes = { /*...*/ };
MyComponent.contextTypes = { /*...*/ };
MyComponent.contextType = { /*...*/ };
MyComponent.displayName = "Hello";
MyComponent.defaultProps = { /*...*/ };
MyComponent.propTypes = { /*...*/ };

Rule Options

...
"react/static-property-placement": [<enabled>]  // `static public field` enabled
...

or alternatively:

...
"react/static-property-placement": [<enabled>, <string>]
...

or alternatively:

...
"react/static-property-placement": [<enabled>, <string>, {
  childContextTypes: <string>,
  contextTypes: <string>,
  contextType: <string>,
  defaultProps: <string>,
  displayName: <string>,
  propTypes: <string>,
}]
...

The <string> value must be one these options:

• static public field
• static getter
• property assignment

The options schema defined above allows you to specify different rules for the different property fields available.

Example configuration

This is only an example, we do not recommend this as a configuration.

...
"react/static-property-placement": ["warn", "property assignment", {
  childContextTypes: "static getter",
  contextTypes: "static public field",
  contextType: "static public field",
  displayName: "static public field",
}]
...

Based on the above configuration:

• defaultProps and propTypes will both enforce the property assignment rule.
• childContextTypes will enforce the static getter rule.
• contextTypes, contextType, and displayName will enforce the static public field rule.

When Not To Use It

If you have no placement preference for React's static class properties.