Severity: warning
Category: lint
Stage: Stage 3

Description

A binding reuses a name already declared in an enclosing scope (function, block, for, or catch). Shadowing makes it easy to read the wrong variable and hides bugs during refactors.

Example

// ✗ lint warning
const id: number = 1

export function f(id: number): number {   // SJS-L014 — shadows outer id
  return id
}

Fix

Rename the inner binding to a distinct name:

// ✓ correct
const id: number = 1

export function f(userId: number): number {
  return userId
}

Configuration

{
  "lint": {
    "L014": "error" | "warn" | "off"
  }
}

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

Related codes

• SJS-L012 — unused declaration