vscode-extension-samples/virtual-document-sample/src/cowsay.d.ts

declare module 'cowsay' {

	export interface CowsayOptions {
		text: string;
		cow?: string;
		eyes?: string;
		tongue?: string;
		wrap?: boolean;
		wrapLength?: number;
		mode?: 'b' | 'd' | 'g' | 'p' | 's' | 't' | 'w' | 'y'
	}

	export function say(options: CowsayOptions): string;
}