Linting

@unthrown/oxlint is an oxlint plugin that turns two of unthrown's theses into automated checks. The library can't make the type system forbid a lazy E on its own — a lint rule can.

pnpm add -D @unthrown/oxlint oxlint

Rules

unthrown/no-ambiguous-error-type

The E in Result<T, E> / AsyncResult<T, E> should name the anticipated domain failures (Thesis #1) — not "anything went wrong". This flags the catch-all error types:

import type { Result } from "unthrown";

type A = Result<User, unknown>; // ✗ flagged
type B = Result<User, Error>; // ✗ flagged
type C = Result<User, {}>; // ✗ flagged

type D = Result<User, NotFound>; // ✓
type E = Result<User, "not_found" | "denied">; // ✓
type F = Result<User, never>; // ✓ — an intentionally error-free result

The whole point of the defect channel is that bugs don't belong in E; this rule keeps them out.

unthrown/prefer-async-result

Prefer AsyncResult<T, E> over Promise<Result<T, E>>. A raw Promise<Result> can still reject, reintroducing the throw channel that AsyncResult is designed to eliminate. Autofixable.

type Slow = Promise<Result<User, NotFound>>; // ✗ → AsyncResult<User, NotFound>

Both rules resolve where Result / AsyncResult were imported from, so they only fire on unthrown's types — a Result from another library is ignored.

Setup

Register the plugin and turn its rules on in your .oxlintrc.json:

{
  "jsPlugins": [{ "name": "unthrown", "specifier": "@unthrown/oxlint" }],
  "rules": {
    "unthrown/no-ambiguous-error-type": "error",
    "unthrown/prefer-async-result": "error"
  }
}

The default export also exposes a recommended preset — an oxlint config that registers the plugin and enables both rules — for setups that build their config programmatically (import unthrown from "@unthrown/oxlint" → unthrown.recommended).

oxlint is a peer dependency; JS plugins require oxlint ≥ 1.69.