Resolve Promises in sequence or in parallel

resolve-promises.ts

/**
 * Resolves a list of deferred tasks in parallel or in sequence.
 */
 async function resolvePromises<const T extends readonly (() => any)[]>(
    deferreds: T,
    parallel?: boolean
): Promise<{ -readonly [P in keyof T]: T[P] extends () => infer R ? Awaited<R> : unknown }> {
    if (parallel) {
        return Promise.all(deferreds.map(deferred => deferred())) as any;
    } else {
        const values: Promise<any>[] = [];
        for (const deferred of deferreds) {
            values.push(await deferred());
        }
        return values as any;
    }
}