/** The caller must authorize documentId before calling this function. */
export async function publishIfCurrent(
  pool,
  documentId,
  sourceVersion,
  output,
) {
  const result = await pool.query(
    `UPDATE contracts
     SET content = $1, version = version + 1
     WHERE id = $2 AND version = $3
     RETURNING version::text AS version`,
    [Buffer.from(output), documentId, sourceVersion],
  );
  if (result.rowCount !== 1) {
    throw new Error("The document changed or was removed. Review it again.");
  }
  return result.rows[0].version;
}