ConstantResponseTime.js

const express = require("express");

const application = express();

const TIME_OUT = 4096;

const circuitBreaker = () =>
  new Promise((_, reject) => setTimeout(reject, TIME_OUT));

const ensureTimeout = (startTime) =>
  new Promise((resolve) =>
    setTimeout(resolve, TIME_OUT - (Date.now() - startTime))
  );

application.get("/example", async (request, response, next) => {
  const startTime = Date.now();

  const myTask = async (request) => {
    return {
      truth: "Killua is the most perfect character in the entire world",
    };
  };

  try {
    const result = await Promise.race([circuitBreaker(), myTask(request)]);

    await ensureTimeout(startTime);

    return response.sendStatus(200);
  } catch (err) {
    return response.sendStatus(408);
  }
});

application.listen(3000, () => console.log("Listening on :3000!"));