retry sample

retry.js

/*eslint no-console: 0 */

const retryDelay = 100;
const retryCount = 10;

function execute() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      const x = Math.random();
      if (x > 0.8) {
        resolve(x);
      } else {
        reject(x);
      }
    }, 100);
  });
}

function delay(asyncFunc, time, count) {
  console.log(`retry ${count}`);
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      asyncFunc().then((x) => {
        console.log(`success: ${x}`);
        resolve(x);
      }).catch((x) => {
        console.log(`failure: ${x}`);
        reject(x);
      });
    }, time);
  });
}


let p = execute();
let t = retryDelay;
for (let i = 0; i < retryCount; i++) {
  p = p.catch(delay.bind(null, execute, t, i + 1));
  t *= 2;
}

p.then((a) => {
  console.log('ok:' + a);
}).catch((a) => {
  console.log('ng:' + a);
});