Why does mongoose crash my bot over this error?

Question

My bot crashes everytime on this error, when using mongoose and just cannot know how to fix it.

0|Trinity  | [07:26:07] Cluster 0 | [Aug 08 2021 07:26:07] Rethink log: TypeError: Cannot read property 'autoRole' of null
0|Trinity  |     at /root/TrinityVPS/src/events/guildMemberAdd.js:7:20
0|Trinity  |     at immediate (/root/TrinityVPS/node_modules/mongoose/lib/model.js:4870:18)
0|Trinity  |     at process._tickCallback (internal/process/next_tick.js:61:11)
0|Trinity  | [07:26:07] Cluster Manager | cluster 0 disconnected
0|Trinity  | [07:26:07] Cluster Manager | cluster 0 died

This is my code:

const Guild = require('../db/models/Guild');

exports.handle = async function (guild, member) {

    try {
        Guild.findOne({ guildID: guild.id }, function (err, doc) {
            if(doc.autoRole.enabled) {
                if(doc.autoRole.role) {
                    member.addRole(guild.roles.find(rl=> rl.name === doc.autoRole.role).id, "Trinity's autorole.")
                }
            }

            if(doc.logsChannel.enabled) {
                if(doc.logsChannel.channelID) {
                    this.bot.createMessage(doc.logsChannel.channelID, {
                        embed: {
                            author: {
                                name: `${member.username}#${member.discriminator}`,
                                icon_url: member.avatarURL
                            },
                            color: 0x2196F3,
                            timestamp: new Date(),
                            fields: [
                                {
                                    name: "Member Joined",
                                    value: `**${member.username}** has joined **${guild.name}**`
                                }
                            ]
                        }
                    })
                }
            }
        })
    } catch (err) { }
}

This is autorole code:

async function autoroleCommand (msg, args) {
    // const db = await this.db.getGuild(msg.channel.guild.id);
    // const prefix = db ? db.prefix : this.config.options.prefix;

    Guild.findOne({ guildID: msg.guildID }, function (err, doc) {
        let auto;

        if (!doc.autoRole.enabled) auto = `Status: deactivated.`;
        else auto = `Status: active.`

        let roleid;

        if (!doc.autoRole.role) roleid = `No role has being set.`
        else roleid = `Role is set to: ${doc.autoRole.role}`

        if (!args[0]) {
            return msg.channel.createMessage({
                embed: {
                    color: 0x2196F3,
                    description: `Autorole configuration for this server:\n${auto}\n${roleid}`
                }
            });
        }

        switch(args[0]) {

            case 'role': {
                var role = args.slice(1).join(' ');
                if(!msg.member.permissions.has('manageGuild') && !this.config.options.devs.includes(msg.author.id)) return msg.channel.createMessage('You are missing the `manageGuild` permission!<:notdone:334852376034803714>');
                if(role.length === 0) return msg.channel.createMessage('Role is a required argument!\nUsage: `autorole role <role>`');
                if(!msg.channel.guild.roles.find(rl => rl.name === role)) return msg.channel.createMessage(`I couldn't find the role \`${role}\`. <:notdone:334852376034803714>`);

                if(role === doc.autoRole.role) {
                    return msg.channel.createMessage('That role is already set as the autorole.')
                } else {
                    doc.autoRole.role = role;
                    doc.save();

                    msg.channel.createMessage('Role has been set! :ok_hand:');
                }
                break;
            }

            case 'disable': {
                if(!msg.member.permissions.has('manageGuild') && !this.config.options.devs.includes(msg.author.id)) return msg.channel.createMessage('You are missing the `manageGuild` permission!<:notdone:334852376034803714>');

                if(doc.autoRole.enabled === false) {
                    return msg.channel.createMessage('Autorole is already disabled.')
                } else {
                    doc.autoRole.enabled = false;
                    doc.save().then(async () => {
                        await msg.channel.createMessage('Successfully disabled autorole. To enable autorole: `autorole enable`')
                    })
                }
                break;
            }

            case 'enable': {
                if(!msg.member.permissions.has('manageGuild') && !this.config.options.devs.includes(msg.author.id)) return msg.channel.createMessage('You are missing the `manageGuild` permission!<:notdone:334852376034803714>');

                if(doc.autoRole.enabled === true) {
                    return msg.channel.createMessage('Autorole is already true.')
                } else {
                    doc.autoRole.enabled = true;
                    doc.save().then(async () => {
                        await msg.channel.createMessage('Successfully enabled autorole. To disable autorole: `autorole disable`')
                    })
                }
                break;
            }

            case 'help':
                msg.channel.createMessage('To set autorole, use the following command: `autorole role <role>`\nTo enable autorole: `autorole enable`\nTo disable autorole: `autorole disable`')
        }
    })
}

I don't understand as in my code i made sure to check if its enabled then proceeds, but it just crashes. It also does this for my doc.logsChannel.channelID and proceeds to crash my bot. How can i fix this?

Answer 1

The issue is because doc is null, i'm assuming because no Guild exists with the guildID of whatever msg.guildID is.

Then because doc is null, anywhere in your code where you are doing doc.autorole will error with Cannot read property 'autoRole' of null.

Basically you need to decide what you want to do when doc is null (when a Guild with the given guildID is not found). Perhaps you simply want to return with some kind of error message. Whatever you decide, you cannot access properties of a null value .