promisolock

Useful to handle the number of promises to start in a Promise.all for long and resource-intensive operations.

Install

$ npm install promisolock
# or
$ yarn add promisolock

Usage

const promisolock = require("promisolock");


promisolock(2).all([
 () => Promise.resolve("P1"), // Starts immediately
 () => Promise.resolve("P2"), // Starts immediately
 () => Promise.resolve("P3"), // Await for one of the above promises to be fulfilled
 () => Promise.resolve("P4"), // etc
]).then(console.log).catch(console.error);
//=> ["P1", "P2", "P3", "P4"]

async function main() {

  await promisolock(3)
    .all(["P1", "P2", "P3", "P4"].map((str) => () => Promise.resolve(str)))
    .then(console.log)
    .catch(console.error);

};

main();
//=> ["P1", "P2", "P3", "P4"]

API

promisolock(max).all(callbacks)

max?: number; 
// Number of promises to start simultaneously, default 1.

callbacks?: Array<() => any> 
// Promises to start in a promise.all, default [].

Inspired by @SlimIO/Lock