Cleanup + cargo fmt

Cleaned up loop to skip 2nd access to `tree.node_mut`, and rust fmt the
unit tests.

Author: amirshukayev

src/lib.rs

@@ -843,12 +843,14 @@ impl<'a, T: 'a> NodeMut<'a, T> {
             }
         };
 
-        // Update parent for all siblings in the chain
         let mut child_id = new_child_ids.0;
         loop {
-            unsafe { self.tree.node_mut(child_id).parent = Some(self.id); }
-            if child_id == new_child_ids.1 { break; }
-            child_id = unsafe { self.tree.node_mut(child_id).next_sibling.unwrap() };
+            let child = unsafe { self.tree.node_mut(child_id) };
+            child.parent = Some(self.id);
+            child_id = match child.next_sibling {
+                Some(id) => id,
+                None => break,
+            };
         }
 
         if self.node().children.is_none() {
@@ -885,12 +887,14 @@ impl<'a, T: 'a> NodeMut<'a, T> {
             }
         };
 
-        // Update parent for all siblings in the chain
         let mut child_id = new_child_ids.0;
         loop {
-            unsafe { self.tree.node_mut(child_id).parent = Some(self.id); }
-            if child_id == new_child_ids.1 { break; }
-            child_id = unsafe { self.tree.node_mut(child_id).next_sibling.unwrap() };
+            let child = unsafe { self.tree.node_mut(child_id) };
+            child.parent = Some(self.id);
+            child_id = match child.next_sibling {
+                Some(id) => id,
+                None => break,
+            };
         }
 
         if self.node().children.is_none() {

tests/node_mut.rs

@@ -512,10 +512,10 @@ fn reparent_from_id_append_multiple_siblings() {
         .reparent_from_id_append(c_id);
 
     let b = tree.get(b_id).unwrap();
-    let x = b.first_child().unwrap();  // original child of b
-    let d = x.next_sibling().unwrap();  // first reparented child
-    let e = d.next_sibling().unwrap();  // middle reparented child
-    let f = e.next_sibling().unwrap();  // last reparented child
+    let x = b.first_child().unwrap(); // original child of b
+    let d = x.next_sibling().unwrap(); // first reparented child
+    let e = d.next_sibling().unwrap(); // middle reparented child
+    let f = e.next_sibling().unwrap(); // last reparented child
 
     // All children should now have 'b' as their parent
     assert_eq!(Some(b), x.parent());
@@ -544,7 +544,7 @@ fn reparent_from_id_prepend_multiple_siblings() {
         .reparent_from_id_prepend(c_id);
 
     let b = tree.get(b_id).unwrap();
-    let d = b.first_child().unwrap();  // first reparented child
+    let d = b.first_child().unwrap(); // first reparented child
     let e = d.next_sibling().unwrap(); // middle reparented child
     let f = e.next_sibling().unwrap(); // last reparented child
     let x = f.next_sibling().unwrap(); // original child of b