eslint-plugin-result-guard

Flags a neverthrow Result/ResultAsync value that's dropped without being checked, chained, awaited-and-checked, or explicitly discarded.

TypeScript's type system won't force you to look at the Err branch — there's nothing like Rust's #[must_use]. This rule is that enforcement.

Install

npm install -D eslint-plugin-result-guard

Usage

// eslint.config.js
import resultGuard from "eslint-plugin-result-guard";

export default [
  {
    plugins: { "result-guard": resultGuard },
    rules: {
      "result-guard/no-unhandled-result": "error",
    },
  },
];

Requires type-aware linting (parserOptions.projectService or parserOptions.project pointing at a real tsconfig.json), since the rule checks the actual TypeScript type of each expression, not just its syntax.

doWork(id); // flagged: Result value never checked

const result = doWork(id); // fine — captured for later handling
void doWork(id); // fine — explicit, intentional discard
doWork(id).match(onOk, onErr); // fine — handled inline

What this doesn't catch (yet)

const result = doWork(id); console.log(result.value); — captured but never checked before an unsafe access. Catching that needs real control-flow analysis and is planned as a separate rule.

License

MIT