'use strict';

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

const timers = require('timers/promises');

class Logger {

#file = null;

#path = '';

constructor(path) {

this.#path = path;

return this.#init(path);

}

async #init(path) {

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

return this;

}

async log(message) {

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

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

console.log(msg);

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

}

async [Symbol.dispose]() {

console.log('Going to close file (dispose)');

console.log('First sync block end (dispose)');

await this.#file.close();

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

// You can do any async finalization logic here

// - Send notifications, write logs

// - Clear cache, release allocated memory

// - Collect and save statistics, etc.

await timers.setTimeout(1000);

console.log('After timeout (dispose)');

console.log(`Logger is still visible ${this.#path} (dispose)`);

}

}

const main = async () => {

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

await logger.log('Open');

await logger.log('Do something');

};

main().then(() => {

console.log('After first sync block of dispose');

});