Module: Function

For example, when you want to work with JavaScript code which looks like:

import greeter from "super-greeter";
greeter("Hello world");

To handle both importing via UMD and modules:

// Type definitions for [~THE LIBRARY NAME~] [~OPTIONAL VERSION NUMBER~]
// Project: [~THE PROJECT NAME~]
// Definitions by: [~YOUR NAME~] <[~A URL FOR YOU~]>
/*~ This is the module template file for function modules.
*~ You should rename it to index.d.ts and place it in a folder with the same name as the module.
*~ For example, if you were writing a file for "super-greeter", this
*~ file should be 'super-greeter/index.d.ts'
// Note that ES6 modules cannot directly export class objects.
// This file should be imported using the CommonJS-style:
// import x = require('[~THE MODULE~]');
// Alternatively, if --allowSyntheticDefaultImports or
// --esModuleInterop is turned on, this file can also be
// imported as a default import:
// import x from '[~THE MODULE~]';
// Refer to the TypeScript documentation at
// to understand common workarounds for this limitation of ES6 modules.
/*~ If this module is a UMD module that exposes a global variable 'myFuncLib' when
*~ loaded outside a module loader environment, declare that global here.
*~ Otherwise, delete this declaration.
export as namespace myFuncLib;
/*~ This declaration specifies that the function
*~ is the exported object from the file
export = Greeter;
/*~ This example shows how to have multiple overloads for your function */
declare function Greeter(name: string): Greeter.NamedReturnType;
declare function Greeter(length: number): Greeter.LengthReturnType;
/*~ If you want to expose types from your module as well, you can
*~ place them in this block. Often you will want to describe the
*~ shape of the return type of the function; that type should
*~ be declared in here, as this example shows.
*~ Note that if you decide to include this namespace, the module can be
*~ incorrectly imported as a namespace object, unless
*~ --esModuleInterop is turned on:
*~ import * as x from '[~THE MODULE~]'; // WRONG! DO NOT DO THIS!
declare namespace Greeter {
export interface LengthReturnType {
width: number;
height: number;
export interface NamedReturnType {
firstName: string;
lastName: string;
/*~ If the module also has properties, declare them here. For example,
*~ this declaration says that this code is legal:
*~ import f = require('super-greeter');
*~ console.log(f.defaultName);
export const defaultName: string;
export let defaultLength: number;

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MHMohamed Hegazy  (53)
OTOrta Therox  (13)
DRDaniel Rose  (1)

Last updated: Jul 22, 2024