Throw a Literal Value

ID

javascript.no_throw_literal

Severity

high

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

JavaScript

Tags

best-practice, reliability

Description

Reports throw statements whose argument is a bare literal value: a string, number, boolean, null, undefined, object literal, array literal, regex, or template literal. JavaScript permits throwing any value, but only Error instances carry a stack trace and are recognised by the standard instanceof Error discrimination in catch handlers.

Rationale

Throwing a non-Error value:

  • Loses the stack trace — the value crosses the catch boundary with no information about where it originated.

  • Breaks try { …​ } catch (e) { if (e instanceof Error) …​ } patterns and TypeScript’s narrowing of unknown in catch.

  • Produces unhelpful messages in unhandled-rejection / uncaught-exception logs.

  • Forces every catch handler that wants the stack to wrap the thrown value, which is easy to forget.

// Bad
throw "Order not found";
throw { code: 404 };
throw null;

Remediation

Throw an Error (or a domain-specific subclass) so the runtime captures the stack and downstream handlers can rely on the standard contract.

// Good
throw new Error("Order not found");
throw new NotFoundError("Order not found", { code: 404 });

If you need to attach extra data, set properties on the Error instance or define a subclass — don’t throw a bare object.

References