```ts
export function safeDivide(a: number, b: number): number {
  if (!Number.isFinite(num) || !Number.isFinite(b)) {
    throw new Error('Both arguments must be finite numbers.');
  } else if (b === 0 || Number.isNaN(b)) {
    throw new Error('Division by zero or NaN is not allowed.');
  }
  return a / b;
}
```