wschurman / mux

Creates a promise that waits for the promises in nested data structures and resolves to data structures of the same form. It recursively traverses the input data structure and multiplexes its promises.

mux

A simple and convenient function that resolves promises in data structures like arrays, objects, Maps, and Sets

What is mux?

Mux is a function that multiplexes promises in nested data structures and resolves them like this:

await mux({
  a: asyncFunction1(),
  b: asyncFunction2(),
});

// Result:
{
  a: result1,
  b: result2,
}

Installing mux

yarn add @expo/mux

And import it like this:

import mux from '@expo/mux';

More examples

You can also pass in deeply nested data structures like this:

await mux({
  a: {
    b: asyncFunction1(),
  },
});

// Result:
{
  a: {
    b: result1,
  },
}

Mux supports several standard JavaScript data structures:

await mux(new Set([
  asyncFunction1(),
  asyncFunction2(),
]));

// Result:
new Set([
  result1,
  result2,
])

And if your promises themselves result in data structures, mux will recurse into them and resolve the nested promises.

await mux([
  Promise.resolve({
    a: asyncFunction1(),
  }),
]);

// Result:
[
  {
    a: result1,
  },
]

Check out the test suite for even more examples.

Interesting use cases

If you've discovered a particularly interesting way to use mux, add it here and send a PR to share it.