refactor(lib): [fileURLToPath] input validation

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>

Author: unicornware

src/internal/validate-file-url.mts

@@ -0,0 +1,38 @@
+/**
+ * @file Internal - validateFileURL
+ * @module pathe/internal/validateFileURL
+ */
+
+import validateURLString from '#internal/validate-url-string'
+import {
+  ERR_INVALID_URL_SCHEME,
+  type ErrInvalidArgType,
+  type ErrInvalidUrlScheme
+} from '@flex-development/errnode'
+
+/**
+ * Check if `value` is a `file:` {@linkcode URL} object or string.
+ *
+ * @internal
+ *
+ * @param {unknown} value
+ *  Value to check
+ * @param {string} name
+ *  Name of invalid argument or property
+ * @return {value is URL | string}
+ *  `true` if `value` is `file:` URL object or string
+ * @throws {ErrInvalidArgType}
+ *  If `value` is not `URL` object or string
+ * @throws {ErrInvalidUrlScheme}
+ *  If `value` is not a `file:` URL object or string
+ */
+function validateFileURL(
+  value: unknown,
+  name: string
+): value is URL | string {
+  validateURLString(value, name)
+  if (String(value).startsWith('file:')) return true
+  throw new ERR_INVALID_URL_SCHEME('file')
+}
+
+export default validateFileURL

src/lib/__tests__/file-url-to-path.spec.mts

@@ -1,7 +1,7 @@
 /**
  * @file Unit Tests - fileURLToPath
  * @module pathe/lib/tests/unit/fileURLToPath
- * @see https://github.com/nodejs/node/blob/v23.2.0/test/parallel/test-url-fileurltopath.js
+ * @see https://github.com/nodejs/node/blob/v23.4.0/test/parallel/test-url-fileurltopath.js
  */
 
 import process from '#internal/process'

src/lib/file-url-to-path.mts

@@ -6,15 +6,14 @@
 import { isWindows } from '#internal/constants'
 import domainToUnicode from '#internal/domain-to-unicode'
 import process from '#internal/process'
-import validateURLString from '#internal/validate-url-string'
+import validateFileURL from '#internal/validate-file-url'
 import isDeviceRoot from '#lib/is-device-root'
 import isSep from '#lib/is-sep'
 import sep from '#lib/sep'
 import toPosix from '#lib/to-posix'
 import {
   ERR_INVALID_FILE_URL_HOST,
   ERR_INVALID_FILE_URL_PATH,
-  ERR_INVALID_URL_SCHEME,
   type ErrInvalidFileUrlHost,
   type ErrInvalidFileUrlPath,
   type ErrInvalidUrlScheme
@@ -49,9 +48,7 @@ function fileURLToPath(
   url: URL | string,
   options?: FileUrlToPathOptions | null | undefined
 ): string {
-  validateURLString(url, 'url')
-
-  if (!String(url).startsWith('file:')) throw new ERR_INVALID_URL_SCHEME('file')
+  validateFileURL(url, 'url')
   if (typeof url === 'string') url = new URL(url)
 
   /**