feat(VfsPath): Add VfsPath::root() method

src/path.rs

@@ -142,6 +142,23 @@ impl VfsPath {
         })
     }
 
+    /// Returns the root path of this filesystem
+    ///
+    /// ```
+    /// # use vfs::{MemoryFS, VfsError, VfsFileType, VfsPath};
+    /// let path = VfsPath::new(MemoryFS::new());
+    /// let directory = path.join("foo/bar")?;
+    ///
+    /// assert_eq!(directory.root(), path);
+    /// # Ok::<(), VfsError>(())
+    /// ```
+    pub fn root(&self) -> VfsPath {
+        VfsPath {
+            path: "".to_string(),
+            fs: self.fs.clone(),
+        }
+    }
+
     /// Creates the directory at this path
     ///
     /// Note that the parent directory must exist.

src/test_macros.rs

@@ -1019,6 +1019,13 @@ macro_rules! test_vfs_readonly {
                 );
             }
 
+            #[test]
+            fn root() {
+                let root = create_root();
+                assert_eq!(root, root.root());
+                assert_eq!(root.join("foo/bar").unwrap().root(), root.root());
+            }
+
             #[test]
             fn eq() {
                 let root = create_root();