Execute several functions in a transaction

transaction.ts

export type fn = () => Error | null;
export type tfn = { run: fn, revert: fn };

export const doInTransaction = async (i: tfn[]): Promise<Error | null> => {
    const reverts: fn[] = [];
    for (const fn of i) {
        try {
            const err = await fn.run();
            if (err) {
                throw err;
            }
            reverts.push(fn.revert);
        } catch (error) {
            const rreverts = reverts.reverse();
            for (const rfn of rreverts) {
                const err = await rfn();
                if (err) {
                    return err;
                }
            }

            return error;
        }
    }
    return null;
};