Mapped type in TS doesn't return nested type-CodePudding

I have this sort of type :

type Schema = {
  name: {
    type: string
  }
  age: {
    type: number
  }
}

I would like to have a type which flatten it.

I expect this:

type MyType<Schema> = { 
  name: string
  age: number
}

But my try to express that doesn't succeed :

type UIType<Schema> = {
  [Key in keyof Schema]: Schema[Key].type
}

The error thrown is "Member 'type' implicitly has an 'any' type.(7008)".

CodePudding user response：

If you define a type:

type ObjTypeFromSchema<S extends Record<string, { type: any }>> = { 
    [K in keyof S]: S[K]["type"] 
}

then you should be able to throw any schema that conforms to Record<string, { type: any }> at it.

In your case

type O = ObjTypeFromSchema<Schema>;

gives a type for O of:

{
    name: string;
    age: number;
}