resolve.js

class PromiseCopy{

  static resolve( value ){
     /* 
        1. We return a new Promise and pass the value to resolve method if Promise.resolve is called directly.
        2. The resolve method of executor runs this same code with this instance added. 
     */ 
    if( !( this instanceof PromiseCopy ) ) return new PromiseCopy( res => res( value ) ) ; 
    
    //return if promise is settled.
    if( this.#state !== states.pending )return ;
 
    //If value is a thenable object we call Promise.resolve recursively by passing it to value.then.
    if( isThenable( value ) ) return value.then( PromiseCopy.resolve.bind( this ), PromiseCopy.resolve.bind( this ) ); 
      
 
    this.#state = states.fulfilled ;
    this.#result = value ;

    this.#dispatchCallbacks();
    
  }
  
  #dispatchCallbacks(){ /* */ } ;

}