preserve initially empty nodes

Author: eush77

index.js

@@ -28,7 +28,7 @@ module.exports = function (ast, opts, predicate) {
         return preorder(child, index, node);
       });
 
-      if (!newNode.children.length && opts.cascade) {
+      if (opts.cascade && !newNode.children.length && node.children.length) {
         return null;
       }
     }

test/test.js

@@ -84,6 +84,23 @@ it('should cascade remove parent nodes', function (t) {
 });
 
 
+it('should not cascade-remove nodes that were empty initially', function (t) {
+  var ast = u('node', [
+    u('node', []),
+    u('node', [
+      u('leaf')
+    ])
+  ]);
+
+  ast = filter(ast, 'node');
+
+  t.deepEqual(ast, u('node', [
+    u('node', [])
+  ]));
+  t.end();
+});
+
+
 it('should call iterator with `index` and `parent` args', function (t) {
   var ast = u('root', [
     u('node', [