dtslint/docs/strict-export-declare-modifiers.md

strict-export-declare-modifiers

Avoid adding the declare keyword unnecessarily. Do add the export keyword unnecessarily, because sometimes it is necessary and we want to be consistent.

Bad:

export declare function f(): void;
declare function g(): void;
interface I {}

Good:

export function f(): void;
export function g(): void;
export interface I {}