From cc8e3343cf0256c7444bba1fd4ceb12a730846c2 Mon Sep 17 00:00:00 2001
From: Antony Male <antony.male@gmail.com>
Date: Wed, 5 Mar 2014 12:37:46 +0000
Subject: [PATCH] Finish off (?) the PropertyChangedExtensionsTests

---
 Stylet/PropertyChangedExtensions.cs           |  1 +
 .../PropertyChangedExtensionsTests.cs         | 32 +++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/Stylet/PropertyChangedExtensions.cs b/Stylet/PropertyChangedExtensions.cs
index 1ec8631..cab47b5 100644
--- a/Stylet/PropertyChangedExtensions.cs
+++ b/Stylet/PropertyChangedExtensions.cs
@@ -31,6 +31,7 @@ namespace Stylet
                 this.binder = new WeakReference(binder);
                 this.inpc = new WeakReference<INotifyPropertyChanged>(inpc);
                 this.propertyName = propertyName;
+                // We need to keep this strongly, in case its target is a compiler-generated class instance
                 this.handler = handler;
             }
 
diff --git a/StyletUnitTests/PropertyChangedExtensionsTests.cs b/StyletUnitTests/PropertyChangedExtensionsTests.cs
index e6a1447..5845ee2 100644
--- a/StyletUnitTests/PropertyChangedExtensionsTests.cs
+++ b/StyletUnitTests/PropertyChangedExtensionsTests.cs
@@ -169,14 +169,30 @@ namespace StyletUnitTests
             var weakBinding = new WeakReference<BindingClass>(binding);
 
             var notifying = new NotifyingClass();
-            // Retain binder, in case that affects anything
-            var binder = binding.BindWeak(notifying);
+            binding.BindWeak(notifying);
 
             binding = null;
             GC.Collect();
             Assert.IsFalse(weakBinding.TryGetTarget(out binding));
         }
 
+        [Test]
+        public void WeakBindingRetainsClassIfIPropertyChangedBindingRetained()
+        {
+            var binding = new BindingClass();
+
+            // Means of determining whether the class has been disposed
+            var weakBinding = new WeakReference<BindingClass>(binding);
+
+            var notifying = new NotifyingClass();
+            // Retain this
+            var binder = binding.BindWeak(notifying);
+
+            binding = null;
+            GC.Collect();
+            Assert.IsTrue(weakBinding.TryGetTarget(out binding));
+        }
+
         [Test]
         public void WeakBindingDoesNotRetainNotifier()
         {
@@ -191,5 +207,17 @@ namespace StyletUnitTests
             GC.Collect();
             Assert.IsFalse(weakNotifying.TryGetTarget(out notifying));
         }
+
+        [Test]
+        public void WeakBindingUnbinds()
+        {
+            string newVal = null;
+            var c1 = new NotifyingClass();
+            var binding = c1.BindWeak(this, x => x.Bar, x => newVal = x);
+            binding.Unbind();
+            c1.Bar = "bar";
+
+            Assert.AreEqual(null, newVal);
+        }
     }
 }