Severity: warning
Category: lint
Stage: Stage 3

Description

A match expression must contain at least one arm. An empty match is almost certainly a mistake and will always throw at runtime when evaluated.

Example

type Status = Active | Inactive

// ✗ lint warning
const r = match s {}   // SJS-L006

Fix

Add arms for every variant, or remove the match if it is not needed:

// ✓ correct
const r = match s {
  Active => 1,
  Inactive => 0,
}

Configuration

{
  "lint": {
    "L006": "error" | "warn" | "off"
  }
}

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

Related codes

• SJS-E007 — non-exhaustive match (type error when variants are missing)
• SJS-L007 — redundant match arm