```ts
/** A divided by B, throwing when divisor is zero or inputs are not finite numbers. */
export function safeDivide(a: number, b: number): number {
  if (typeof a !== 'number' || typeof b !== 'number') throw new Error('Inputs must be numbers.');
  if (!Number.isFinite(a) || !Number.isFinite(b)) throw new Error('Inputs must be finite numbers.');
  if (b === 0 || b === -0) throw new Error('Divisor cannot be zero.');

  return a / b;
}
```