[no-unused-var] False positive for imported interfaces used in declare global

[flopes89]

Repro

{
  "plugins": ["react", "@typescript-eslint"],
  "extends": ["eslint:recommended", "plugin:react/recommended", "plugin:@typescript-eslint/recommended"],
  "rules": {
    "no-unused-vars": "warn",
  }
}

// ../server/servicesTypes.ts

export interface Token {
	principal_id: string;
}

import { Token } from "../server/servicesTypes";

declare global {
	namespace Express {
		export interface Request {
			token: Token;
		}
	}
}

Expected Result

File does not yield any warnings.

Actual Result

ESLint warning on the import line:

ESLint: 'Token' is defined but never used. (no-unused-vars)

Additional Info

When I remove the declare global and instead export namespace is the top-most declaration, the warning goes away.

Versions

package	version
@typescript-eslint/eslint-plugin	2.6.0
@typescript-eslint/parser	2.6.0
TypeScript	3.6.2
ESLint	6..6.0
node	10.15.3
npm	6.4.1

[bradzacher]

please use our rule @typescript-eslint/no-unused-vars-experimental instead

[ma-zal]

@bradzacher Can you provide details, how to use it? I was not able to found the documentation.

please use our rule @typescript-eslint/no-unused-vars-experimental instead

[armano2]

@ma-zal https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/no-unused-vars-experimental.md