两个数组和1个对象合并成一个数组对象的排列组合

const userIds = [1, 2]
const dates = ["2021-01-09", "2021-01-10"]
const obj = {
  "time_from": "09:00:00",
  "time_to": "20:00:00",
  "rest_hours": 1
}

最终结果

[{
  "user_id": 1,
  "date":"2021-01-09"
  "time_from": "09:00:00",
  "time_to": "20:00:00",
  "rest_hours": 1
},{
  "user_id": 1,
  "date":"2021-01-10"
  "time_from": "09:00:00",
  "time_to": "20:00:00",
  "rest_hours": 1
},{
  "user_id": 2,
  "date":"2021-01-09"
  "time_from": "09:00:00",
  "time_to": "20:00:00",
  "rest_hours": 1
},{
  "user_id": 2,
  "date":"2021-01-10"
  "time_from": "09:00:00",
  "time_to": "20:00:00",
  "rest_hours": 1
}]