From d5e8dc35d0c7886e849a848b3a3f5d30b25a682c Mon Sep 17 00:00:00 2001
From: Rafael Weinstein <rafaelw@chromium.org>
Date: Mon, 16 Dec 2013 13:27:58 -0800
Subject: [PATCH] Fix ObserverTransform.getValue/setValue/discardChanges

ObserverTransform needs to conform to the contract of Observable:

-getValue/setValue do not affect the last reported value (synchronously retrieve or set the underlying value)
-discardChanges sets the last reported value to the current value

R=arv
BUG=

Review URL: https://codereview.appspot.com/41260044
---
 src/observe.js | 13 ++++++-------
 tests/test.js  |  8 ++++++--
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/observe.js b/src/observe.js
index c555570..68c124f 100644
--- a/src/observe.js
+++ b/src/observe.js
@@ -922,11 +922,12 @@
     },
 
     getValue: function() {
-      return this.observable_.getValue();
+      return this.getValueFn_(this.observable_.getValue());
     },
 
     discardChanges: function() {
-      return this.getValueFn_(this.observable_.discardChanges());
+      this.value_ = this.getValueFn_(this.observable_.discardChanges());
+      return this.value_;
     },
 
     deliver: function() {
@@ -934,11 +935,9 @@
     },
 
     setValue: function(value) {
-      this.value_ = this.setValueFn_(value);
-      if (this.dontPassThroughSet_ || !this.observable_.setValue)
-        return;
-
-      return this.observable_.setValue(this.value_);
+      value = this.setValueFn_(value);
+      if (!this.dontPassThroughSet_ && this.observable_.setValue)
+        return this.observable_.setValue(value);
     },
 
     close: function() {
diff --git a/tests/test.js b/tests/test.js
index b5d2e86..b96d9f3 100644
--- a/tests/test.js
+++ b/tests/test.js
@@ -333,8 +333,12 @@ suite('ObserverTransform', function() {
 
     observer.setValue(2);
     assert.strictEqual(obj.foo, 1);
-    assert.strictEqual(2, observer.discardChanges());
-    assertNoChanges();
+    assert.strictEqual(2, observer.getValue());
+    assertPathChanges(2, 4);
+
+    obj.foo = 10;
+    assert.strictEqual(20, observer.getValue());
+    assertPathChanges(20, 2);
 
     observer.close();
   });