ES2015 module syntax is preferred over custom TypeScript modules and namespaces @typescript-eslint/no-namespace #2

Question

Many years I had been used following code

export interface User {
  readonly name: User.Name;
  readonly address: User.Address;
}

export namespace User {
  export interface Name {
    readonly first: string;
    readonly last: string;
  }

  export interface Address {
    readonly country: string;
    readonly city: string;
  }
}

I like Name and Address interfaces accessible via User interface, that helps to prevent name conflicts, show relation, etc.

Right now, I have a fight with ESLint rule @typescript-eslint/no-namespace

Is it possible to achieve same typing without violation of the rule?

Answer 1

There is no way to use a namespace without violating the lint rule.

However you could do-away with the namespace entirely by inlining your types:

export interface User {
  readonly name: {
    readonly first: string;
    readonly last: string;
  };
  readonly address: {
    readonly country: string;
    readonly city: string;
  };
}

If you want to specifically reference the address or name type later in code you can then do so using an indexed type reference:

type UserName = User['name'];
type UserAddress = User['address'];

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