title: Can't I add static values to native javascript Promises?
body: <p>I'm iterating through an array of objects to build a collection of Promises that I want to await in parallel. I need a specific property (unrelated to the promise) to persist in the result, but I can't just add it as a property of the Promise, it gets wiped away when the promise resolves:</p>
  
  <pre><code>let arrayOPromises = someArrayOfValues.map((promiseParams) =&gt; {
     let response = someFunctionThatReturnsAPromise(promiseParams);
     response.valueINeedToPersist = promiseParams.objectPropertyINeed; //unique to each iteration of map()
     return response;
  });
  
  await Promise.all(arrayOPromises);
  
  // gives me the resolved promises, but not the added value
  
  // [resolvedPromise1, resolvedPromise2];
  
  // resolvedPromise1.valueINeedToPersist === 'undefined'
  </code></pre>