Function extend

packages/jss-plugin-extend/src/index.js:73–77

* Recursively extend styles.

(style, rule, sheet, newStyle = {})

 * Recursively extend styles.
 */
function extend(style, rule, sheet, newStyle = {}) {
  mergeExtend(style, rule, sheet, newStyle)
  mergeRest(style, rule, sheet, newStyle)
  return newStyle
}

/**
 * Handle `extend` property.