Severity: warning
Category: lint
Stage: Stage 3

Description

A throw statement bypasses SJS's preferred error model. Recoverable failures should be returned as Result<T, E> so callers handle them explicitly (RFC-0004).

throw remains valid for truly exceptional cases (programmer errors, unrecoverable state).

Example

// ✗ lint warning
export function parseId(raw: string): number {
  if (raw.length === 0) throw "empty"   // SJS-L017
  return Number(raw)
}

Fix

Return Result and let callers match:

type Result<T, E> = Ok(T) | Err(E)

export function parseId(raw: string): Result<number, string> {
  if (raw.length === 0) return Err("empty")
  return Ok(Number(raw))
}

Configuration

{
  "lint": {
    "L017": "error" | "warn" | "off"
  }
}

Default: "warn" in standard mode, "error" in --strict mode.

Related codes

• SJS-L016 — unhandled Result
• SJS-E007 — non-exhaustive match