Result Monad

Installation: If not already installed, add the package with pnpm add @efesto-cloud/result.

Use this skill to keep Result<T, E> usage consistent across the project.

Core Rules

• Create success with Result.ok(value).
• Create failure with Result.err(error).
• Check outcome with result.isFailure() or result.isSuccess().
• Throw only when explicitly desired with result.unwrapOrThrow().
• For fallback values, use result.else(() => fallback).
• Execute side effects with result.run(fn) — runs fn on success data, no-op on failure.
• Serialize to plain object with result.toObject() — returns ISuccess<T> | IFailure<E>.
• Deserialize with Result.fromObject(obj) — reconstructs from a plain IResult<T, E> object.
• Integrate Zod validation with Result.fromZod(zodParseResult) — converts SafeParseReturnType to Result.

Common Mistakes To Avoid

• Do not use isErr().