TypeError: Cannot read properties of undefined (reading 'set') discord.js v14

Question

I'm currently making a bot for my friend's server, but I have discovered an error which is

TypeError: Cannot read properties of undefined (reading 'set') at Client.client.handleCommands (C:\Users\Admin\Documents\galax-bot\functions\handlers\handleCommands.js:19:37) at Object. (C:\Users\Admin\Documents\galax-bot\index.js:19:8) I have read the documents and searched for multiple resources but I still cannot solve the problem

    // handleCommands.js

 

    const { ClientUser } = require("discord.js");
    const { REST } = require("@discordjs/rest")
    const { Routes } = require("discord-api-types/v9")
    const fs = require("fs")

    module.exports = (client) => {
    client.handleCommands = async () => {
        const commandFolders = fs.readdirSync(`./commands`);
        for (const folder of commandFolders) {
            const commandFiles = fs
                .readdirSync(`./commands/${folder}`)
                .filter((file) => file.endsWith(".js"));

            const { commands, commandArray } = client;
            for (const file of commandFiles) {
                const command = require(`../../commands/${folder}/${file}`)
                if (command) {
                    console.log(command.data)
                    client.commands.set(command.name, command);
                commandArray.push(command.data.toJSON());
                console.log(`Command: ${command.data.name} has been passed through the 
    handler`)
                }
            }
        }
    }

    const clientId = '1033991303165390878';
    const guildId = '905393827488071701';
    const rest = new REST({ version: "9" 
    }).setToken("Not letting you see the token");
    try {
        console.log('Started refreshing application (/) commands.');

        rest.put(Routes.applicationCommands(clientId, guildId), {
            body: client.commandArray,
        });

        console.log('Successfully reloaded application (/) commands.');
     } catch (error) {
        console.error(error);
     }
    }

    // index.js

    require("dotenv").config
    const { Client, Collection , GatewayIntentBits, EmbedBuilder, PermissionsBitField, 
    Permissions } = require("discord.js");
    const Token = process.env.token
    const prefix = '^';
    const fs = require('fs')
    const client = new Client({ intents: [GatewayIntentBits.Guilds, 
    GatewayIntentBits.GuildMessages, GatewayIntentBits.MessageContent] });
    client.commads = new Collection();
    client.commandArray = []
    const functionFolders = fs.readdirSync(`./functions`)

    for (const folder of functionFolders) {
    const functionFiles = fs
    .readdirSync(`./functions/${folder}`)
    .filter((file) => file.endsWith(".js"));
    for (const file of functionFiles) 
    require(`./functions/${folder}/${file}`)(client);
    }
    client.handleEvents();
    client.handleCommands();
    client.login(Token)

Answer 1

Yeah, as @Andreas said, client.commands is undefined, and with it client.commands.set.

This error happens always when a variable whose value should be passed, is undefined.