Promise-race-map NPM

promise-race-map

A Promise.race implementation that works with JavaScript map.

Background

Promise.race is useful when you need either one of the Promise to complete before proceeding. But if you need to process the result, it isn't easy to distinguish between two promises.

Before using `promise-race-map`

Before using this package, you will need to write code like this.

const p1 = fn1();
const p2 = fn2();

// Given both Promise do not return falsy values
const { r1, r2 } = await Promise.race([
  () => p1.then(res => ({ r1: res })),
  () => p2.then(res => ({ r2: res }))
]);

if (r1) {
  // Process result from fn1()
} else {
  // Process result from fn2()
}

After using `promise-race-map`

After using this package, you can write shorter and more readable code like this.

const { r1, r2 } = await Promise.race({
  r1: fn1(),
  r2: fn2()
});

if (r1) {
  // Process result from fn1()
} else {
  // Process result from fn2()
}