fix: crash on window access in node environments

Fix retrieve not working in Node environments caused by accessing `window` without first checking if it exists.

README.md

@@ -2,7 +2,7 @@
 
 [![Tests passing](https://github.com/kleinfreund/retrieve/workflows/Tests/badge.svg)](https://github.com/kleinfreund/retrieve/actions)
 
-A convenience wrapper around fetch for the browser (well, anything that has `fetch` really).
+A convenience wrapper around fetch for the browser (and anything that has `fetch`).
 
 This package’s files are distributed in the ES module format and have not been transpiled.
 
@@ -124,11 +124,11 @@ The request URL.
 - `URL`: Will be used as-is.
 - `string`:
 	- Absolute URL string: Will be used as-is.
-	- Relative URL path string: Will be turned into an absolute URL (using `config.baseUrl` if set; otherwise `window.location.origin`).
+	- Relative URL path string: Will be turned into an absolute URL (using `config.baseUrl`).
 
 ##### `baseUrl` (optional)
 
-**Default**: `window.location.origin`
+**Default**: `window.location.origin` in browser environments; otherwise, `undefined`
 
 Base for request URL. Ignored if `config.url` is a `URL` object or an absolute URL `string`.
 

dist/retrieve.d.ts

@@ -5,13 +5,13 @@ interface RetrieveConfig {
      * - `URL`: Will be used as-is.
      * - `string`:
      *   - Absolute URL string: Will be used as-is.
-     *   - Relative URL path string: Will be turned into an absolute URL (using `config.baseUrl` if set; otherwise `window.location.origin`).
+     *   - Relative URL path string: Will be turned into an absolute URL (using `config.baseUrl`).
      */
     url: string | URL;
     /**
      * Base for request URL. Ignored if `url` is a URL object or an absolute URL string.
      *
-     * **Default**: `window.location.origin`
+     * **Default**: `window.location.origin` in browser environments; otherwise, `undefined`
      */
     baseUrl?: string | URL;
     /**

src/retrieve.ts

@@ -7,14 +7,14 @@ export interface RetrieveConfig {
 	 * - `URL`: Will be used as-is.
 	 * - `string`:
 	 *   - Absolute URL string: Will be used as-is.
-	 *   - Relative URL path string: Will be turned into an absolute URL (using `config.baseUrl` if set; otherwise `window.location.origin`).
+	 *   - Relative URL path string: Will be turned into an absolute URL (using `config.baseUrl`).
 	 */
 	url: string | URL
 
 	/**
 	 * Base for request URL. Ignored if `url` is a URL object or an absolute URL string.
 	 *
-	 * **Default**: `window.location.origin`
+	 * **Default**: `window.location.origin` in browser environments; otherwise, `undefined`
 	 */
 	baseUrl?: string | URL
 
@@ -346,7 +346,8 @@ export async function retrieve(config: RetrieveConfig): Promise<RetrieveResponse
  */
 function createUrl(config: RetrieveConfig): URL {
 	// Process request URL
-	const url = new URL(config.url, config.baseUrl ?? window.location.origin)
+	const baseUrl = config.baseUrl ?? (typeof window !== 'undefined' ? window.location.origin : undefined)
+	const url = new URL(config.url, baseUrl)
 
 	// Turns `params` into query parameters for GET requests
 	if (config.params) {