// sample-types.d.ts: a declaration file.
// Free sample from 99helpers.com/file-types/ts
// It holds only types, never code that runs. It describes JavaScript that
// lives somewhere else, so the compiler and your editor can check how you
// use it. A .d.ts file can't be run, and nothing in it ends up in the output.

// 1. A global variable that a <script> tag provides at run time.
declare const APP_VERSION: string;

// 2. A global function, with an overload for each way it can be called.
declare function formatPrice(cents: number): string;
declare function formatPrice(cents: number, currency: "EUR" | "USD" | "GBP"): string;

// 3. Types for a JavaScript package that ships without any.
declare module "tiny-units" {
  export type Unit = "mm" | "cm" | "m";

  export interface Measurement {
    value: number;
    unit: Unit;
  }

  export function convert(measurement: Measurement, to: Unit): Measurement;

  const version: string;
  export default version;
}

// 4. Declaration merging: adds an optional property to the browser's
//    built-in Window interface instead of replacing it.
interface Window {
  sampleReady?: boolean;
}