Reloading Commands

When writing your commands, you may find it tedious to restart your bot every time for testing the smallest changes. With a command handler, you can eliminate this issue and reload your commands while your bot is running.

WARNING

ESM does not support require and clearing import cache. You can use hot-esmopen in new window to import files without cache. Windows support is experimental per this issueopen in new window.

TIP

This section assumes you followed the Command Handling part.

WARNING

The reload command ideally should not be used by every user. You should deploy it as a guild command in a private guild.

const { SlashCommandBuilder } = require('discord.js');

module.exports = {
	data: new SlashCommandBuilder()
		.setName('reload')
		.setDescription('Reloads a command.')
		.addStringOption(option =>
			option.setName('command')
				.setDescription('The command to reload.')
				.setRequired(true)),
	async execute(interaction) {
		// ...
	},
};

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First off, you need to check if the command you want to reload exists. You can do this check similarly to getting a command.

module.exports = {
	// ...
	async execute(interaction) {
		const commandName = interaction.options.getString('command', true).toLowerCase();
		const command = interaction.client.commands.get(commandName);

		if (!command) {
			return interaction.reply(`There is no command with name \`${commandName}\`!`);
		}
	},
};

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To build the correct file path, you will need the file name. You can use command.data.name for doing that.

In theory, all there is to do is delete the previous command from client.commands and require the file again. In practice, you cannot do this easily as require() caches the file. If you were to require it again, you would load the previously cached file without any changes. You first need to delete the file from require.cache, and only then should you require and set the command file to client.commands:

delete require.cache[require.resolve(`./${command.data.name}.js`)];

try {
	interaction.client.commands.delete(command.data.name);
	const newCommand = require(`./${command.data.name}.js`);
	interaction.client.commands.set(newCommand.data.name, newCommand);
	await interaction.reply(`Command \`${newCommand.data.name}\` was reloaded!`);
} catch (error) {
	console.error(error);
	await interaction.reply(`There was an error while reloading a command \`${command.data.name}\`:\n\`${error.message}\``);
}

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The snippet above uses a try...catch block to load the command file and add it to client.commands. In case of an error, it will log the full error to the console and notify the user about it with the error's message component error.message. Note that you never actually delete the command from the commands Collection and instead overwrite it. This behavior prevents you from deleting a command and ending up with no command at all after a failed require() call, as each use of the reload command checks that Collection again.

Resulting code

If you want to compare your code to the code we've constructed so far, you can review it over on the GitHub repository here open in new window.

# Reloading Commands

# Resulting code

Reloading Commands

Resulting code