no-redundant-should-component-update.md

Prevent usage of shouldComponentUpdate when extending React.PureComponent (react/no-redundant-should-component-update)

Warns if you have shouldComponentUpdate defined when defining a component that extends React.PureComponent. While having shouldComponentUpdate will still work, it becomes pointless to extend PureComponent.

Rule Details

The following patterns are considered warnings:

class Foo extends React.PureComponent {
  shouldComponentUpdate() {
    // do check
  }

  render() {
    return <div>Radical!</div>
  }
}

function Bar() {
  return class Baz extends React.PureComponent {
    shouldComponentUpdate() {
      // do check
    }

    render() {
      return <div>Groovy!</div>
    }
  }
}

The following patterns are not considered warnings:

class Foo extends React.Component {
  shouldComponentUpdate() {
    // do check
  }

  render() {
    return <div>Radical!</div>
  }
}

function Bar() {
  return class Baz extends React.Component {
    shouldComponentUpdate() {
      // do check
    }

    render() {
      return <div>Groovy!</div>
    }
  }
}

class Qux extends React.PureComponent {
  render() {
    return <div>Tubular!</div>
  }
}