如何优化JavaScript中根据总数生成随机数，避免负数出现？

function filterate(list, num = 29) {
    let data = list.map((item, index) => {
      return Array.from({length: Number(item.test)}).map(citem => {
        return {
          min: 0,
          max: 0,
          num: 0,
        }
      })
    })
    
    let max = Math.max(...list.map(i => Number(i.test)));
    let value = 0;
    let current = 1;
    let count = list.reduce((n, i) => n + Number(i.test), 0)
    
    for (let index = 0; index < max; index++) {
      data.forEach((item, k) => {
        if(item[index]){
            
          let step = num / count | 0 // 下取整
          count-- //循环计算step，确保step在剩下的始祖中平均分配
          num-=step
            
          item[index].min = value + 1
          value += step
          item[index].max = value
          item[index].num= Math.floor(Math.random() * (item[index].max - item[index].min + 1)) + item[index].min
        }
      })
    }
    return data;
}