next-resolver


^{Social Media Photo by Jan Genge on Unsplash}


A utility to simpify the repeated unique ID + promise dance.

``js
import nextResolver from 'next-resolver';

const [next, resolve] = nextResolver();

// next unique identifier and its promise
const [id, promise] = next();

// pass the promise around, hold the id ...
// ... so that whenever it's done:
if (condition) {
resolve(id, value);

// or reject via
resolve(id, null, new Error('reason'));
}
`

The default nextResolver() accepts an optional callback that will receive a unique identifier that can be used to return something else:

`js
// use strings instead of numbers as IDs
const [next, resolve] = nextResolver(String);

const [id, promise] = next();
typeof id; // string

// use any Map key variant
const [next, resolve] = nextResolver(id => {
// make it stronger (not really useful)
return ${id}-${crypto.randomUUID()};
// make it a unique ref
return { id };
});
`

Please note that if the returned value is still awaited, the next id will be passed to create a new identifier (so don't put too much logic within the id creation, it's already granted to be unique per that logic/session).

This is mostly needed in case you want to brand your async operations, so that something like a prefix would be enough:

`js
const [next, resolve] = nextResolver(id => my-logic-${id});
``

And that's all folks 🥕