added a comment and assert

adopt · Apr 12, 2017 · 601e3e5 · 601e3e5
1 parent 1fdf825
commit 601e3e5
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/lib/src/daxe_node.dart b/lib/src/daxe_node.dart
@@ -580,7 +580,7 @@ abstract class DaxeNode {
 
   /**
    * Inserts [newdn] as a child of this node before [beforedn].
-   * beforedn may be null, in which case it is inserted as the last child.
+   * [beforedn] may be null, in which case it is inserted as the last child.
    */
   void insertBefore(DaxeNode newdn, DaxeNode beforedn) {
     assert(beforedn == null || this == beforedn.parent);
@@ -602,8 +602,12 @@ abstract class DaxeNode {
     }
   }
 
+  /**
+   * Inserts [newdn] as a child of this node after [afterdn].
+   * [afterdn] may not be null.
+   */
   void insertAfter(DaxeNode newdn, DaxeNode afterdn) {
-    assert(this == afterdn.parent);
+    assert(afterdn != null && this == afterdn.parent);
     if (afterdn._nextSibling == null)
       appendChild(newdn);
     else