有没有办法在 object 的接口中使用字符串字面量类型？

Question

I have a type Color ,

type Color = 'yellow' | 'red' | 'orange'

And I have an object which interface is ColorSetting .

interface ColorSetting {
  id: string
  yellow?: boolean
  red?: boolean
  orange?: boolean
}

I want to use the type Color to simplify interface ColorSetting .

The code I simplified is below:

interface ColorSetting {
  id: string
  [k in Color]?: boolean
}

But I got an error about A computed property name in an interface must refer to an expression whose type is a literal type or a 'unique symbol' type.

How should I use the string literal type correctly in an interface?

Answer 1

Is it important to use a string literal there? Would an enum with string values not suffice:

enum Colors {
  YELLOW = 'yellow',
  RED = 'red',
  ORANGE = 'orange',
}

interface ColorSetting {
  id: string;
  color: Colors;
}

The only downside to this approach is if you would ever need to reverse map this, which typescript doesn't do itself.

I tend not to use literals like this myself, so I'm not sure if this works, but give it a try:

interface ColorSetting {
  id: string;
  color: Color;
}

Basically just use your type as you've declared it, drop the '[k in Color]' bit

Answer 2

I have found a solution, which is useful for me. This solution uses an Intersection Types .

ColorSetting = {
   id: string
 } & {
   [k in Color]?: boolean
 }