old_contents: import React, { PureComponent, Fragment } from 'react';
  import PropTypes from 'prop-types';
  
  import ErrorText from './ErrorText';
  import HelpText from './HelpText';
  
  class ValidationText extends PureComponent {
    render() {
      const { error, help, inverse } = this.props;
  
      return (
        <Fragment>
          {error ? (
            <ErrorText inverse={inverse}>{error}</ErrorText>
          ) : (
            help && <HelpText inverse={inverse}>{help}</HelpText>
          )}
        </Fragment>
      );
    }
  }
  
  ValidationText.propTypes = {
    error: PropTypes.node,
    help: PropTypes.node,
    inverse: PropTypes.bool,
  };
  
  export default ValidationText;
  
new_contents: import React, { PureComponent } from 'react';
  import PropTypes from 'prop-types';
  
  import ErrorText from './ErrorText';
  import HelpText from './HelpText';
  import WarningText from './WarningText';
  
  class ValidationText extends PureComponent {
    render() {
      const { error, inverse, help, warning } = this.props;
  
      if (error) {
        return <ErrorText inverse={inverse}>{error}</ErrorText>;
      }
  
      if (warning) {
        return <WarningText inverse={inverse}>{warning}</WarningText>;
      }
  
      if (help) {
        return <HelpText inverse={inverse}>{help}</HelpText>;
      }
  
      return null;
    }
  }
  
  ValidationText.propTypes = {
    error: PropTypes.node,
    help: PropTypes.node,
    inverse: PropTypes.bool,
    warning: PropTypes.node,
  };
  
  export default ValidationText;
  
subject: add 'warning' prop & implement WarningText