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require-assert-never

Require an empty switch default to call assertNever so discriminated unions remain exhaustive at compile time.

missingAssertNever Rule source Tests Catalog JSON

Why

An empty default silently accepts new union members instead of making the compiler identify the missing case.

Fix

Call assertNever with the discriminant in the exhaustive switch default.

Examples

Before — flagged Do not leave an exhaustive default empty

src/render.ts

declare const kind: "a" | "b";
switch (kind) {
  case "a":
    break;
  case "b":
    break;
  default:
}

After — preferred Make the default exhaustive

src/render.ts

declare const kind: "a" | "b";
switch (kind) {
  case "a":
    break;
  case "b":
    break;
  default:
    assertNever(kind);
}