Haha-Yes/commands/admin/starboard.js

const { Command } = require('discord-akairo');
const fs = require('fs');

class StarBoardCommand extends Command {
    constructor() {
        super('starboard', {
            aliases: ['starboard'],
            category: 'admin',
            channelRestriction: 'guild',
            userPermissions: ['ADMINISTRATOR'],
            description: {
                content: 'Set starboard',
                usage: '[]',
                examples: ['']
            }
        });
    }

    async exec(message) {
        let starboardChannel = message.channel.id;

            fs.readFile(`./starboard/${message.guild.id}.json`, 'utf8', function readFileCallback(err, data){
                if (err){
                    fs.writeFile(`./starboard/${message.guild.id}.json`, `{"starboard": "${starboardChannel}"}`, function (err) {
                        if (err){
                            console.log(err);
                        }
                        return message.channel.send(`This channel have been set as the starboard`);
                    })
                } else {
                    let starboard = JSON.parse(data); //now it an object
                    starboard ['starboard'] = starboardChannel;
                    var json = JSON.stringify(starboard); //convert it back to json
                    fs.writeFile(`./starboard/${message.guild.id}.json`, json, 'utf8', function(err) {
                        if(err) {
                            return console.log(err);
                        } 
            })}});
                return message.channel.send(`This channel have been set as the starboard`);
    }
}

module.exports = StarBoardCommand;