Promise timer

promise-timer.js

let counter = 0;

class MyPromise extends Promise {
  constructor(cb) {
    const stack = (() => { try { throw new Error(); } catch (e) { return e; } })().stack;
    const id = `promise ${counter++}`;

    console.time(id);

    super(function(resolve, reject) {
      return cb.call(
        this,
        function() {
          console.timeLog(id, 'RESOLVE', stack);
          return resolve.apply(this, arguments);
        },
        function() {
          console.timeLog(id, 'REJECT', stack);
          return reject.apply(this, arguments);
        }
      );
    });
  }
}

Promise = MyPromise;

Put at top of bin/www to capture promise times