@atlaskit/editor-common/dist/esm/utils/dedupe.js

A package that contains common classes and components for editor and renderer

export function dedupe() {
  var list = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
  var iteratee = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : function (p) {
    return p;
  };
  /**
               .,
     .      _,'f----.._
     |\ ,-'"/  |     ,'
     |,_  ,--.      /
     /,-. ,'`.     (_
     f  o|  o|__     "`-.
     ,-._.,--'_ `.   _.,-`
     `"' ___.,'` j,-'
       `-.__.,--'
     Gotta go fast!
  */

  var seen = new Set();
  list.forEach(function (l) {
    return seen.add(iteratee(l));
  });
  return list.filter(function (l) {
    var it = iteratee(l);
    if (seen.has(it)) {
      seen.delete(it);
      return true;
    }
    return false;
  });
}