shutdownable

Shutdownable is a Class decorator.

The purpose of this decorator is to add (or modify) an async shutdown method to the class.

The shutdown method will await for any existing calls on other named methods to complete before returning. Once shutdown() has begun, calling any of the other named methods will throw a ShuttingDownError error, preventing them from running.

Installation

npm install shutdownable

Usage

const shutdownable = require('shutdownable');

const delay = (ms) => new Promise(r => setTimeout(r, ms));

class A {
    async init() {
        console.log('init start');
        await delay(1000);
        console.log('init end');
    }

    async run() {
        console.log('run start');
        await delay(2000);
        console.log('run end');
    }
}

// apply the decorator to the class and its methods
shutdownable(A, ['init', 'run']);

async function main() {
    const a = new A();

    setTimeout(async () => {
        console.log('shutting down');
        await a.shutdown();
        console.log('shutdown complete. All init() & run() methods have completed.');
    }, 1500);

    await a.init();
    await Promise.all([
        a.run(),
        a.run(),
        a.run(),
    ]);
    console.log('end of main()');
}
main().catch(console.error);