ily.li/src/SlugGenerator.ts

import {cryptoRandomDictionary} from "swaf/Utils";
import config from "config";
import FileModel from "./models/FileModel";
import {ServerError} from "swaf/HttpError";

const SLUG_DICTIONARY = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
export default async function generateSlug(tries: number): Promise<string> {
    let i = 0;
    do {
        const slug = cryptoRandomDictionary(config.get<number>('newlyGeneratedSlugSize'), SLUG_DICTIONARY);
        if (!await FileModel.getBySlug(slug)) {
            return slug;
        }
        i++;
    } while (i < tries);
    throw new ServerError('Failed to generate slug; newly generated slug size should be increased by 1.');
};