From b7f175bfa9b2786a58718d544fc75c867cd2fa40 Mon Sep 17 00:00:00 2001
From: Chirayu Krishnappa <chirayu@chirayuk.com>
Date: Fri, 30 May 2014 12:04:01 -0700
Subject: [PATCH] fix(element binder): fix memory leak with expando value
 holding onto node

Expando keys are weak references but the values are not.  The
ElementProbe value holds strong references to the node and the injector
keep it from being garbage collected.
---
 lib/core_dom/element_binder.dart              |  1 +
 .../shadow_dom_component_factory.dart         |  5 +--
 test/core_dom/compiler_spec.dart              | 33 ++++++++++++++++++-
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/lib/core_dom/element_binder.dart b/lib/core_dom/element_binder.dart
index 85103f309..d923a4736 100644
--- a/lib/core_dom/element_binder.dart
+++ b/lib/core_dom/element_binder.dart
@@ -319,6 +319,7 @@ class ElementBinder {
     nodeInjector = parentInjector.createChild([nodeModule]);
     probe = _expando[node] = new ElementProbe(
         parentInjector.getByKey(_ELEMENT_PROBE_KEY), node, nodeInjector, scope);
+    scope.on(ScopeEvent.DESTROY).listen((_) {_expando[node] = null;});
 
     _link(nodeInjector, probe, scope, nodeAttrs, formatters);
 
diff --git a/lib/core_dom/shadow_dom_component_factory.dart b/lib/core_dom/shadow_dom_component_factory.dart
index 15807eb79..54bb4aa38 100644
--- a/lib/core_dom/shadow_dom_component_factory.dart
+++ b/lib/core_dom/shadow_dom_component_factory.dart
@@ -179,7 +179,7 @@ class _ComponentFactory implements Function {
 
   Injector createShadowInjector(injector, TemplateLoader templateLoader) {
     var probe;
-   var shadowModule = new Module()
+    var shadowModule = new Module()
       ..bindByKey(typeKey)
       ..bindByKey(_NG_ELEMENT_KEY)
       ..bindByKey(_EVENT_HANDLER_KEY, toImplementation: ShadowRootEventHandler)
@@ -187,9 +187,10 @@ class _ComponentFactory implements Function {
       ..bindByKey(_TEMPLATE_LOADER_KEY, toValue: templateLoader)
       ..bindByKey(_SHADOW_ROOT_KEY, toValue: shadowDom)
       ..bindByKey(_ELEMENT_PROBE, toFactory: (_) => probe);
-      shadowInjector = injector.createChild([shadowModule], name: SHADOW_DOM_INJECTOR_NAME);
+    shadowInjector = injector.createChild([shadowModule], name: SHADOW_DOM_INJECTOR_NAME);
     probe = _expando[shadowDom] = new ElementProbe(
         injector.getByKey(_ELEMENT_PROBE), shadowDom, shadowInjector, shadowScope);
+    shadowScope.on(ScopeEvent.DESTROY).listen((ScopeEvent) {_expando[shadowDom] = null;});
     return shadowInjector;
   }
 }
diff --git a/test/core_dom/compiler_spec.dart b/test/core_dom/compiler_spec.dart
index fab93e00b..02bd7018d 100644
--- a/test/core_dom/compiler_spec.dart
+++ b/test/core_dom/compiler_spec.dart
@@ -727,6 +727,28 @@ void main() {
             expect(_.rootElement.shadowRoot).toBeNotNull();
           }
         }));
+
+        describe('expando memory', () {
+          Expando expando;
+
+          beforeEach(inject((Expando _expando) => expando = _expando));
+
+          ['shadowy', 'shadowless'].forEach((selector) {
+            it('should release expando when a node is freed ($selector)', async(() {
+              _.rootScope.context['flag'] = true;
+              _.compile('<div><div ng-if=flag><$selector>x</$selector></div></div>');
+              microLeap(); _.rootScope.apply();
+              var element = _.rootElement.querySelector('$selector');
+              if (element.shadowRoot != null) {
+                element = element.shadowRoot;
+              }
+              expect(expando[element]).not.toEqual(null);
+              _.rootScope.context['flag'] = false;
+              microLeap(); _.rootScope.apply();
+              expect(expando[element]).toEqual(null);
+            }));
+          });
+        });
       });
 
       describe('bindings', () {
@@ -849,7 +871,6 @@ void main() {
         expect(_.rootElement.text).toEqual('MyController');
       });
     });
-
   }));
 }
 
@@ -975,6 +996,16 @@ class SimpleComponent {
   }
 }
 
+@Component(
+    selector: 'simple2',
+    template: r'{{name}}(<content>SHADOW-CONTENT</content>)')
+class Simple2Component {
+  Scope scope;
+  Simple2Component(Scope this.scope) {
+    scope.context['name'] = 'INNER';
+  }
+}
+
 @Component(
   selector: 'shadowy',
   template: r'With shadow DOM',