@minsky-org/result

Tagged-union Result<T, E> with ok / err / isOk / isErr. Zero dependencies.

Convention: runtime errors travel as a Result; programmer errors throw.

import { err, isErr, ok, type Result } from "@minsky-org/result";

const parsePort = (raw: string): Result<number, string> => {
  const port = Number(raw);
  return Number.isInteger(port) ? ok(port) : err(`not a port: ${raw}`);
};