babel/packages/babel-plugin-transform-es2015-object-super/src/index.js

import ReplaceSupers from "babel-helper-replace-supers";

export default function ({ types: t }) {
  function Property(path, node, scope, getObjectRef, file) {
    let replaceSupers = new ReplaceSupers({
      getObjectRef: getObjectRef,
      methodNode:   node,
      methodPath:   path,
      isStatic:     true,
      scope:        scope,
      file:         file
    });

    replaceSupers.replace();
  }

  let CONTAINS_SUPER = Symbol();

  return {
    visitor: {
      Super(path) {
        let parentObj = path.findParent((path) => path.isObjectExpression());
        if (parentObj) parentObj.node[CONTAINS_SUPER] = true;
      },

      ObjectExpression: {
        exit(path, file) {
          if (!path.node[CONTAINS_SUPER]) return;

          let objectRef;
          let getObjectRef = () => objectRef = objectRef || path.scope.generateUidIdentifier("obj");

          let propPaths: Array = path.get("properties");
          for (let propPath of propPaths) {
            if (propPath.isObjectProperty()) propPath = propPath.get("value");
            Property(propPath, propPath.node, path.scope, getObjectRef, file);
          }

          if (objectRef) {
            path.scope.push({ id: objectRef });
            path.replaceWith(t.assignmentExpression("=", objectRef, path.node));
          }
        }
      }
    }
  };
}