RocketChat/Rocket.Chat

export const getFileExtension = (fileName?: string): string => {
    if (!fileName) {
        return 'file';
    }

    const arr = fileName.split('.');

    if (arr.length < 2 || (arr[0] === '' && arr.length === 2)) {
        return 'file';
    }

    return arr.pop()?.toLocaleUpperCase() || 'file';
};