Typescript: map nested object properties to string

Question

I am wondering if it is possible to create a type which maps properties of an object to a string where if a certain property value is an object himself, it is added to the string preceded by a dot. Let's say we have an object with the following shape

a: {
  b: {
    c: 'hello'
  }
},
x: {
  y: {
    z: 'hello'
  }
}

The resulting type would be: "a" | "x" | "a.b" | "a.b.c" | "x.y" | "x.y.z" My attempt in achieving this resulted in the following code

interface A {
  a: number
  b: {
    c: string
    d: {
      e: {
        f: 'hello'
      }
    }
  }
}

type valueof<T> = T[keyof T]
type str<T> = T extends string ? T : never
type record<T> = valueof<{
  [K in keyof T]: T[K] extends any[] ? never : T[K] extends Record<string, any> ? K | `${str<K>}.${str<record<T[K]>>}` : K
}>

I think that this is technically correct but it will crash typescript because of the infinite recursion so I will not include a playground link. Did anyone think of any other way of doing it?

Typescript: map nested object properties to string

0 Answers0