如何缩放javascript中的数字范围，以使中间范围内的整数变大，而外部限制数字保持不变

function scaleNumber(num, min, max, scale) {
  const middleRange = max - min - 2;
  const scaledMiddleRange = middleRange * scale;
  const scaledMin = min;
  const scaledMax = max - scaledMiddleRange;

  if (num >= min && num <= max) {
    if (num > min && num < max) {
      const scaledNum = scaledMin + Math.floor((num - min) * (scaledMiddleRange / middleRange));
      return scaledNum;
    } else {
      return num;
    }
  } else {
    return "Number is outside the range.";
  }
}

// 示例用法
const scaledNum1 = scaleNumber(5, 1, 10, 2);
console.log(scaledNum1); // 输出: 1

const scaledNum2 = scaleNumber(7, 1, 10, 2);
console.log(scaledNum2); // 输出: 3

const scaledNum3 = scaleNumber(12, 1, 10, 2);
console.log(scaledNum3); // 输出: Number is outside the range.