```typescript
export function slotHits(keys: number[], slots: number): number {
  if (!Number.isInteger(slots) || slots <= 0) {
    throw new Error("Slot count must be a positive integer.");
  }
  const cache: Map<number, number> = new Map();

  let hits = 0;
  for (const key of keys) {
    if (!Number.isInteger(key)) {
      throw new Error("All keys must be integers.");
    }

    const slot = Math.abs(key) % slots;
    const currentSlotValue = cache.get(slot);

    if (currentSlotValue !== undefined && currentSlotValue === key) {
      hits++;
    } else {
      cache.set(slot, key);
    }
  }

  return hits;
}
```