noctbot/bot/src/commands/random_react.ts

import { CommandSet, Action, ActionType } from "src/model/command";
import { Message } from "discord.js";
import { getRepository } from "typeorm";
import { RandomMessageReaction } from "@shared/db/entity/RandomMesssageReaction";
import { client } from "src/client";

const timeout = (ms: number) => new Promise(r => setTimeout(r, ms));

@CommandSet
export class RandomReact {
    @Action(ActionType.MESSAGE)
    async showHelp(actionsDone: boolean, msg: Message) {
        if(actionsDone)
            return false;

        let repo = getRepository(RandomMessageReaction);

        let reactInfo = await repo.findOne({ where: { userId: msg.author.id } });

        if(!reactInfo)
            return false;

        let emote = client.emojis.resolve(reactInfo.reactionEmoteId);

        if(!emote)
            return false;

        if(Math.random() < reactInfo.reactProbability) {
            await timeout(Math.random() * reactInfo.maxWaitMs);
            await msg.react(emote);
        }
        
        return false;
    }
}