'use strict';

// To intercept finalization run

// node --expose-gc 1-registry.js

const fs = require('node:fs/promises');

const registry = new FinalizationRegistry(async (file) => {

await file.close();

console.log('File closed (finalized)');

});

class Logger {

#file = null;

constructor(path) {

return this.#init(path);

}

async #init(path) {

this.#file = await fs.open(path, 'a');

registry.register(this, this.#file, this);

return this;

}

async log(message) {

const timestamp = new Date().toISOString();

const msg = `[${timestamp}] ${message}`;

console.log(msg);

await this.#file.write(`${msg}\n`);

}

}

const main = async () => {

const logger = await new Logger('output.log');

await logger.log('Open');

await logger.log('Do something');

setTimeout(() => {

if (global.gc) gc();

else console.log('Run node with --expose-gc flag');

}, 1000);

};

main();