Feature/improvements

index.d.ts

@@ -0,0 +1,70 @@
+/**
+  @param options   -  The options for renaming.
+
+  @returns         -  The new filename for the downloaded file.
+
+  @description     -  This function is used to determine the filename for each downloaded file.
+*/
+export type RenameFunction = (options: {
+	url: string;
+	index: number;
+	urls: string[];
+}) => string;
+
+/*
+  Options for the multiDownload function.
+ */
+export type Options = {
+	/**
+	  @default undefined  - (use original filenames)
+
+	  @description        - A function that returns the new filename for each downloaded file.
+    */
+	rename?: RenameFunction;
+	/**
+	  The delay time between each file download in milliseconds.
+	  @default 1000
+	 */
+	downloadInterval?: number;
+};
+
+/**
+  @param urls     - The URLs to download.
+
+  @param options  - The options for downloading.
+
+  @returns        - A promise that resolves when all files have been downloaded.
+
+  @description    - Download multiple files from an array of URLs.
+
+  @example
+  ```
+  import { multiDownload } from "multi-download";
+
+  async function downloadFiles() {
+
+  	const urls = [
+  		"https://example.com/file1.txt",
+  		"https://example.com/file2.txt",
+  		"https://example.com/file3.txt",
+  	];
+
+  	try {
+  		await multiDownload(urls, {
+  			rename: ({ url, index }) => `file${index + 1}.txt`,
+  			downloadInterval: 1000,
+  		});
+  		console.log("Files downloaded successfully");
+  	} catch (error) {
+  		console.error("Error downloading files:", error);
+  	}
+
+  }
+
+  await downloadFiles();
+  ```
+ */
+export default function multiDownload(
+	urls: string[],
+	options?: Options
+): Promise<void>;

index.js

@@ -1,6 +1,7 @@
-const delay = milliseconds => new Promise(resolve => {
-	setTimeout(resolve, milliseconds);
-});
+const delay = milliseconds =>
+	new Promise(resolve => {
+		setTimeout(resolve, milliseconds);
+	});
 
 const download = async (url, name) => {
 	const a = document.createElement('a');
@@ -15,15 +16,32 @@ const download = async (url, name) => {
 	a.remove();
 };
 
-export default async function multiDownload(urls, {rename} = {}) {
-	if (!urls) {
+const getName = ({url}) => {
+	const match = url.match(/\/([^/]+)$/);
+	return match ? match[1] : 'file';
+};
+
+export default async function multiDownload(urls = [], options = {}) {
+	const {downloadInterval = 1000, rename = getName} = options;
+	if (!urls?.length) {
 		throw new Error('`urls` required');
 	}
 
-	for (const [index, url] of urls.entries()) {
-		const name = typeof rename === 'function' ? rename({url, index, urls}) : '';
+	if (urls.some(url => typeof url !== 'string')) {
+		throw new Error('`urls` must be an array of strings');
+	}
 
-		await delay(index * 1000); // eslint-disable-line no-await-in-loop
+	if (typeof downloadInterval !== 'number') {
+		throw new TypeError('The `downloadInterval` option must be a number');
+	}
+
+	if (typeof rename !== 'function') {
+		throw new TypeError('The `rename` option must be a function');
+	}
+
+	for (const [index, url] of urls.entries()) {
+		const name = rename({url, index, urls});
+		await delay(index * downloadInterval); // eslint-disable-line no-await-in-loop
 		download(url, name);
 	}
 }

package.json

@@ -11,12 +11,16 @@
 		"url": "https://sindresorhus.com"
 	},
 	"type": "module",
-	"exports": "./index.js",
+	"exports": {
+		"types": "./index.d.ts",
+		"default": "./index.js"
+	},
 	"scripts": {
 		"test": "xo"
 	},
 	"files": [
-		"index.js"
+		"index.js",
+		"index.d.ts"
 	],
 	"keywords": [
 		"browser",

readme.md

@@ -74,6 +74,12 @@ Type: `Function`
 
 A function that accepts an object containing `url`, `index`, and `urls` properties and is expected to return the new filename.
 
+##### downloadInterval
+
+Type: `number`
+
+The delay time between each file download in milliseconds.
+
 ```html
 <button id="download-button" data-files="unicorn.jpg rainbow.jpg">Download</button>
 ```
@@ -84,7 +90,19 @@ import multiDownload from 'multi-download';
 document.querySelector('#download-button').addEventListener('click', event => {
 	const files = event.target.dataset.files.split(' ');
 	multiDownload(files, {
-		rename: ({url, index, urls}) => 'New name.pdf'
+		rename: ({url, index, urls}) => 'New name.pdf',
+	});
+});
+```
+
+```js
+import multiDownload from 'multi-download';
+
+document.querySelector('#download-button').addEventListener('click', event => {
+	const files = event.target.dataset.files.split(' ');
+	multiDownload(files, {
+		rename: ({url, index, urls}) => 'New name.pdf',
+		downloadInterval: 500
 	});
 });
 ```