thingy2.js

// WithWrapper.js
const withWrapper = (Component, name) => ({ wrapper, ...props }) => {
  if (wrapper) {
    return (
      <div className={`${name}_wrapper`}>
        <Component {...props} />
      </div>
    )
  }
  
  return <Component {...props} />
}

// Alert.js
import withWrapper from './withWrapper'

const name = 'alert'

const Alert = withWrapper(({ success, bar, wrapper, children }) => {
  let CSSClass = name
  
  if (success) CSSClass = CSSClass + '-success'
  if (bar) CSSClass = CSSClass + '-bar'
  
  return (
    <div className={CSSClass}>{children}</div>
  )
}, name)

// SomeComponent.js

<Alert wrapper>
  <Alert success bar />
  <Alert success bar />
</Alert>

<Alert success bar />