dispatchcallbacks.js

class PromiseCopy{
  #handlers = [] ;
  #queued = false ;
  
  #dispatchCallbacks(){
      if( this.#state === states.pending )return ;
      if( this.#queued )return ;

      const method = this.#state === states.fulfilled ? 'success' : 'fail' ; //handler method to call

      queueMicrotask( () => {
          //log promise error if promise is rejected and no handlers are available.
          if( this.#state === states.rejected && !this.#handlers.length ) console.error( 'Uncaught (in promisecopy)', this.#result );
          
          for( let handler of this.#handlers ){
            handler[ method ]( this.#result ) ;
          }
          //cleanup activities:
          this.#handlers = []; //remove triggered handlers.
          this.#queued = false ;
      } );
    
      this.#queued = true ;

  }

}