I'm building a discord bot using discord.js. All of my source code is from the official discord.js guide website, and I'm wondering how I could list all declared slash commands to a JSON file commands.json.

Here is my code:

deploy_commands.js:

const { SlashCommandBuilder } = require('@discordjs/builders');
const { REST } = require('@discordjs/rest');
const { Routes } = require('discord-api-types/v9');
const { clientId, guildId, token } = require('./config.json');

const fs = require('node:fs');
const path = require('node:path');

const commands = [];
const commandsPath = path.join(__dirname, 'commands');
const commandFiles = fs.readdirSync(commandsPath).filter(file => file.endsWith('.js'));

for (const file of commandFiles) {
  const filePath = path.join(commandsPath, file);
  const command = require(filePath);
  commands.push(command.data.toJSON());
}

const rest = new REST({ version: '9' }).setToken(token);

rest.put(Routes.applicationGuildCommands(clientId, guildId), { body: commands })
    .then(() => console.log('Successfully registered application commands.'))
    .catch(console.error);

index.js:

const { Client, Collection, Intents } = require("discord.js");
const client = new Client({intents: [Intents.FLAGS.GUILDS]});

const config = require("./config.json");
const { guildId, clientId, token } = require('./config.json');

const fs = require('node:fs');
const path = require('node:path');

client.commands = new Collection();
const commandsPath = path.join(__dirname, 'commands');
const commandFiles = fs.readdirSync(commandsPath).filter(file => file.endsWith('.js'));

for (const file of commandFiles) {
  const filePath = path.join(commandsPath, file);
  const command = require(filePath);
  client.commands.set(command.data.name, command);
}

client.once('ready', () => {
  console.log(`user : ${client.user.tag}\nguildid : ${guildId}\nclientid : ${clientId}`);
});

client.on('interactionCreate', async interaction => {
  if (!interaction.isCommand()) return;
  
  const command = client.commands.get(interaction.commandName);
  
  if (!command) return;
  
  try {
    await command.execute(interaction);
  } catch (error) {
    console.error(error);
    await interaction.reply({content: 'Sorry, there was a problem while executing this command, maybe try again later?', ephemeral: true});
  }
});

client.login(token);

deploy_commands.js is a file for deploying commands, and what I want to do is to save all the declared slash commands and transfer all of them to a JSON file.