Function invariant

packages/ecma402-abstract/utils.ts:131–139

(
  condition: boolean,
  message: string,
  Err: any = Error
)

}

export function invariant(
  condition: boolean,
  message: string,
  Err: any = Error
): asserts condition {
  if (!condition) {
    throw new Err(message)
  }
}

// Native NumberFormat coerces non-primitive inputs via ToPrimitive (calling
// `toString()`) before feeding them to ToIntlMathematicalValue, so a