don't add no op mutations

packages/core/src/diff.rs

@@ -628,10 +628,12 @@ impl<'b> VirtualDom {
             }
 
             let id = self.find_last_element(&new[last]);
+            if nodes_created > 0 {
                 self.mutations.push(Mutation::InsertAfter {
                     id,
                     m: nodes_created,
-            });
+                })
+            }
             nodes_created = 0;
         }
 
@@ -652,10 +654,12 @@ impl<'b> VirtualDom {
                 }
 
                 let id = self.find_first_element(&new[last]);
+                if nodes_created > 0 {
                     self.mutations.push(Mutation::InsertBefore {
                         id,
                         m: nodes_created,
                     });
+                }
 
                 nodes_created = 0;
             }
@@ -676,12 +680,14 @@ impl<'b> VirtualDom {
             }
 
             let id = self.find_first_element(&new[first_lis]);
+            if nodes_created > 0 {
                 self.mutations.push(Mutation::InsertBefore {
                     id,
                     m: nodes_created,
                 });
             }
         }
+    }
 
     /// Push all the real nodes on the stack
     fn push_all_real_nodes(&mut self, node: &'b VNode<'b>) -> usize {