noctcore-contracts/restrict-throw-to-taxonomy

throw only members of your error taxonomy — never an ad hoc built-in nor a bare value.

Recommended preset: error · Autofix: no · Suggestions: no · Type information: not needed

Why

A codebase that throws a curated set of error types can handle them exhaustively at the boundary: one place maps AppError → HTTP status, ValidationError → 422, and so on. Throwing an arbitrary built-in (TypeError, RangeError) or, worse, a bare value (throw 'nope', throw { code }) breaks that: a non-Error carries no stack and no cause, and an unclassified error falls through every instanceof branch.

What it flags

• throw new SomethingError(...) whose constructor is not in the allow list.
• throw <non-Error value> — a string, number, boolean, template literal, object, or array literal.

Incorrect · 3 reports

// built-in not in the taxonomy
throw new TypeError('bad');

// bare values
throw 'boom';
throw { code: 500 };

Correct

// default allow is ['Error']
throw new Error('boom');
try { work(); } catch (err) { throw err; }

What it does not flag

Conservative on the ambiguous forms. A bare identifier (throw err — the re-throw), a member (throw ctx.error), and a call (throw makeError()) are all left alone: a syntactic rule cannot know whether they resolve to an Error, and re-throwing a caught error is the most common throw there is.

Options

Option	Type	Default	Meaning
allow	string[]	['Error']	Constructor names permitted as throw targets. Extend it with your base errors and any built-ins you legitimately raise.

'noctcore-contracts/restrict-throw-to-taxonomy': ['error', {
  allow: ['AppError', 'ValidationError', 'NotFoundError', 'TypeError'],
}]

The default ['Error'] is intentionally strict — it assumes a taxonomy rooted at Error and treats every other built-in as something you should opt into. Widen allow to match your project’s error model on day one.

When not to use it

If you have no error taxonomy yet, or intentionally throw built-ins throughout, leave this rule off until you have a base error class worth enforcing.