带索引的对象的打字稿定义模式

Question

I have data that looks like this:

let equipment:Equipment =  {
  "1": {
    "name": "abc",
    "data": 123
  },
  "2": {
    "name": "def",
    "data": 234
  },
  "3": {
    "name": "ghi",
    "data": 345
  },
  ...
}

This would be easy to put in an array, but my equipment ID's start with 1 and I don't want to deal with the logic of excluding the [0] (which would be null) element.

Given this, I have come up with the following TypeScript Declaration Files.

interface Equipment 
{ 
  [ k: number ]: EquipmentBase;
}

interface EquipmentBase 
{
  name: string
  data: number
}

Further, when I return this equipment object with others I need to put it in a JSON object which requires yet another interface declaration.

interface EquipmentObj
{
  equipment: Equipment
}

/* returns {equipment: 
  {
  "1": {
    "name": "abc",
    "data": 123
  },
  "2": {
    "name": "def",
    "data": 234
  },
  "3": {
    "name": "ghi",
    "data": 345
  },
  ...
  }
}

*/

This feels like an excessive number of declarations (Equipment, EquipmentObj) just to declare an object that holds data. Is there a different/better way to minimize the number of declarations that I am using?

Answer 1

Well, you can do this:

interface EquipmentObj
{
  equipment: {
    [k: number]: {
      name: string
      data: number
    }
  }
}

But then, you can no longer declare anything as one of the inner types.

So if you need to type a variable, parameter, or return type as Equipment or EquipmentBase , then you could not fold that one in.