Property is not assignable to string index in interface

Question

I have the following interfaces:

export interface Meta {
  counter: number;
  limit: number;
  offset: number;
  total: number;
}

export interface Api          


        

Answer 1

You can use an intersection of two interfaces:

interface Api<T> {
    [key: string]: T[];  
}

type ApiType<T> = Api<T> & {
    meta: Meta;
}

declare let x: ApiType<string>;

let a = x.meta // type of `a` is `Meta`
let b = x["meta"]; // type of `b` is `Meta`

let p = x["someotherindex"] // type of `p` is `string[]`
let q = x.someotherindex // type of `q` is `string[]`

Answer 2

The presented best solution didn't work when I've tried to implement this interface. I ended up nesting part with dynamic key. Maybe someone will find it useful:

interface MultichannelConfiguration {
  channels: {
    [key: string]: Configuration;
  }
  defaultChannel: string;
}