RocketChat/Rocket.Chat

import { type IMessage } from '@rocket.chat/core-typings';
import type BadWordsFilter from 'bad-words';

export class BeforeSaveBadWords {
    badWords: BadWordsFilter | null = null;

    async configure(badWordsList?: string, goodWordsList?: string) {
        const { default: Filter } = await import('bad-words');

        const options = {
            list:
                badWordsList
                    ?.split(',')
                    .map((word) => word.trim())
                    .filter(Boolean) || [],
            // library definition does not allow optional definition
            exclude: undefined,
            splitRegex: undefined,
            placeHolder: undefined,
            regex: undefined,
            replaceRegex: undefined,
            emptyList: undefined,
        };

        this.badWords = new Filter(options);

        if (goodWordsList?.length) {
            this.badWords.removeWords(...goodWordsList.split(',').map((word) => word.trim()));
        }
    }

    disable() {
        this.badWords = null;
    }

    async filterBadWords({ message }: { message: IMessage }): Promise<IMessage> {
        if (!message.msg || !this.badWords) {
            return message;
        }

        try {
            message.msg = this.badWords.clean(message.msg);
        } catch (error) {
            // ignore
        }

        return message;
    }
}