Fix types

Related to GH-17.

Author: wooorm

lib/index.js

@@ -8,7 +8,6 @@
  * @typedef {BufferEncoding|{encoding?: null|BufferEncoding, mode: Mode?, flag?: string}} WriteOptions
  *
  * @typedef {string|Uint8Array} Path Path of the file.
- * @typedef {typeof import('url').URL} URL WHATWG URL
  * @typedef {Path|URL|Options|VFile} Compatible Things that can be
  *   passed to the function.
  */
@@ -21,7 +20,7 @@
 
 import fs from 'fs'
 import path from 'path'
-import {fileURLToPath} from 'url'
+import {URL, fileURLToPath} from 'url'
 import buffer from 'is-buffer'
 import {VFile} from 'vfile'
 
@@ -37,7 +36,7 @@ import {VFile} from 'vfile'
 export function toVFile(options) {
   if (typeof options === 'string' || buffer(options)) {
     options = {path: String(options)}
-  } else if (options && options.href && options.origin) {
+  } else if (options instanceof URL) {
     options = {path: fileURLToPath(options)}
   }