@fbltd/async/dist/bin/dependency/vanilla/race.stream.js

Miscellaneous async utils

import { symAI } from "../../constants.js";
import { PromiseConfiguration } from "../../promise-configuration.js";
export function raceStream(deps) {
    let externalDispose = new PromiseConfiguration();
    const [keys, streams] = Object
        .entries(deps)
        .reduce((acc, [key, dep]) => {
        acc[0].push(key);
        acc[1].push(dep[symAI]());
        return acc;
    }, [[], []]);
    function isDisposed() {
        return streams.some((s) => s.isDisposed);
    }
    return {
        dispose: () => !isDisposed() && externalDispose.resolve({ done: true, value: void 0 }),
        get isDisposed() {
            return isDisposed();
        },
        [symAI]() {
            const done = { done: true };
            return {
                next: async () => {
                    if (externalDispose.isFulfilled)
                        return done;
                    const res = await Promise.race([
                        externalDispose.promise,
                        ...streams.map(s => s.next())
                    ]);
                    if (externalDispose.isFulfilled)
                        return done;
                    externalDispose = new PromiseConfiguration();
                    if (res.done)
                        return res;
                    const value = keys.reduce((acc, key) => {
                        acc[key] = deps[key].value;
                        return acc;
                    }, {});
                    return { done: false, value };
                }
            };
        }
    };
}