Fix #48

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres
 to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Fixed
+- Fixed EPERM Exception when datastore is at the root of a disk on Windows [#48](https://github.com/seald/nedb/issues/48)
+
 ## [4.0.2] - 2023-05-05
 ### Fixed
 - Fixed typo in documentation [#36](https://github.com/seald/nedb/pull/36)

lib/persistence.js

@@ -373,7 +373,11 @@ class Persistence {
    * @private
    */
   static async ensureDirectoryExistsAsync (dir, mode = DEFAULT_DIR_MODE) {
-    await storage.mkdirAsync(dir, { recursive: true, mode })
+    const parsedDir = path.parse(path.resolve(dir))
+    // this is because on Windows mkdir throws a permission error when called on the root directory of a volume
+    if (process.platform !== 'win32' || parsedDir.dir !== parsedDir.root) {
+      await storage.mkdirAsync(dir, { recursive: true, mode })
+    }
   }
 }