fix(shadowdom): fixes bug with nested content tags.

IntermediateContentTags were not properly accounting for nodes that pass
through them.

Author: rkirov

lib/core_dom/content_tag.dart

@@ -4,6 +4,7 @@ abstract class _ContentStrategy {
   void attach();
   void detach();
   void insert(Iterable<dom.Node> nodes);
+  Iterable<dom.Node> get nodes;
 }
 
 /**
@@ -14,6 +15,7 @@ class _ShadowDomContent implements _ContentStrategy {
   void attach(){}
   void detach(){}
   void insert(Iterable<dom.Node> nodes){}
+  Iterable<dom.Node> get nodes => null;
 }
 
 /**
@@ -35,6 +37,7 @@ class _RenderedTranscludingContent implements _ContentStrategy {
   dom.ScriptElement _endScript;
 
   Iterable<dom.Node> _currNodes;
+  Iterable<dom.Node> get nodes => _currNodes;
 
   _RenderedTranscludingContent(this._content, this._sourceLightDom);
 
@@ -50,7 +53,7 @@ class _RenderedTranscludingContent implements _ContentStrategy {
 
   void insert(Iterable<dom.Node> nodes){
     final p = _endScript.parent;
-    if (p != null && ! _equalToCurrNodes(nodes)) {
+    if (p != null && !_equalToCurrNodes(nodes)) {
       _removeNodesBetweenScriptTags();
       _currNodes = nodes.toList();
       p.insertAllBefore(nodes, _endScript);
@@ -95,19 +98,22 @@ class _IntermediateTranscludingContent implements _ContentStrategy {
   final SourceLightDom _sourceLightDom;
   final DestinationLightDom _destinationLightDom;
   final Content _content;
+  Iterable<dom.Node> _currNodes;
+  Iterable<dom.Node> get nodes => _currNodes;
 
   _IntermediateTranscludingContent(this._content, this._sourceLightDom, this._destinationLightDom);
 
   void attach(){
     _sourceLightDom.redistribute();
+    _destinationLightDom.addContentTag(_content);
   }
 
   void detach(){
     _sourceLightDom.redistribute();
   }
 
   void insert(Iterable<dom.Node> nodes){
-    _content.element.nodes = nodes;
+    _currNodes = nodes.toList();
     _destinationLightDom.redistribute();
   }
 }
@@ -127,6 +133,7 @@ class Content implements AttachAware, DetachAware {
     view.addContent(this);
   }
 
+  Iterable<dom.Node> get nodes => strategy._currNodes;
   void attach() => strategy.attach();
   void detach() => strategy.detach();
   void insert(Iterable<dom.Node> nodes) => strategy.insert(nodes);

lib/core_dom/light_dom.dart

@@ -7,6 +7,7 @@ abstract class SourceLightDom {
 abstract class DestinationLightDom {
   void redistribute();
   void addViewPort(ViewPort viewPort);
+  void addContentTag(Content content);
   bool hasRoot(dom.Element element);
 }
 
@@ -15,6 +16,7 @@ class LightDom implements SourceLightDom, DestinationLightDom {
 
   final List<dom.Node> _lightDomRootNodes = [];
   final Map<dom.Node, ViewPort> _ports = {};
+  final Map<dom.Node, Content> _contentTags = {};
 
   final Scope _scope;
 
@@ -45,6 +47,10 @@ class LightDom implements SourceLightDom, DestinationLightDom {
     redistribute();
   }
 
+  void addContentTag(Content content) {
+    _contentTags[content.element] = content;
+  }
+
   //TODO: vsavkin Add dirty flag after implementing view-scoped dom writes.
   void redistribute() {
     _scope.rootScope.domWrite(() {
@@ -82,7 +88,9 @@ class LightDom implements SourceLightDom, DestinationLightDom {
       if (_ports.containsKey(root)) {
         list.addAll(_ports[root].nodes);
       } else if (root is dom.ContentElement) {
-        list.addAll(root.nodes);
+        if (!_contentTags.containsKey(root))
+          throw new Exception('Unmatched content tag encountered during redistibution.');
+        list.addAll(_contentTags[root].nodes);
       } else {
         list.add(root);
       }
@@ -105,4 +113,4 @@ void redistributeNodes(Iterable<Content> contents, List<dom.Node> nodes) {
       nodes.removeWhere(matchSelector);
     }
   }
-}
+}

test/core_dom/compiler_spec.dart

@@ -312,6 +312,8 @@ void main() {
           ..bind(OuterComponent)
           ..bind(InnerComponent)
           ..bind(InnerInnerComponent)
+          ..bind(SimpleOuterComponent)
+          ..bind(SimpleInnerComponent)
           ..bind(OuterWithDivComponent)
           ..bind(OneTimeDecorator)
           ..bind(OnceInside)
@@ -615,6 +617,13 @@ void main() {
         expect(element).toHaveText('OUTTER:INNER(OUTTER)');
       }));
 
+      it('should create simple nested components', async((VmTurnZone zone) {
+        var element = _.compile(r'<div><simple-outer>TEXT</simple-outer></div>');
+        microLeap();
+        _.rootScope.apply();
+        expect(element).toHaveText('OUTER(INNER(TEXT))');
+      }));
+
       it('should create a component that can access parent scope', async((VmTurnZone zone) {
         _.rootScope.context['fromParent'] = "should not be used";
         _.rootScope.context['val'] = "poof";
@@ -1744,6 +1753,22 @@ class InnerComponent implements ScopeAware {
   InnerComponent();
 }
 
+@Component(
+    selector: 'simple-inner',
+    template: 'INNER(<content></content>)'
+)
+class SimpleInnerComponent implements ScopeAware {
+  Scope scope;
+}
+
+@Component(
+    selector: 'simple-outer',
+    template: 'OUTER(<simple-inner><content></content></simple-inner>)'
+)
+class SimpleOuterComponent implements ScopeAware {
+  Scope scope;
+}
+
 @Component(
     selector: 'innerinner',
     template: 'INNERINNER(<content select=".left"></content>,<content select=".right"></content>)'