The default value for NullableString should be null (was "")

mojo/public/js/bindings/struct_unittests.js

Index: mojo/public/js/bindings/struct_unittests.js
diff --git a/mojo/public/js/bindings/struct_unittests.js b/mojo/public/js/bindings/struct_unittests.js
index d4a568ccf41f8bde7995025345535ed3d791a2fa..2583a86da16a7f55c522c4251209e48b189b44ed 100644
--- a/mojo/public/js/bindings/struct_unittests.js
+++ b/mojo/public/js/bindings/struct_unittests.js
@@ -26,8 +26,7 @@ define([
     expect(new testStructs.RectPair({second: r}).first).toBeNull();
 
     var nr = new testStructs.NamedRegion();
-    // TODO(hansmuller): nr.name should be null, see crbug.com/417039.
-    expect(nr.name).toBe("");
+    expect(nr.name).toBeNull();
     expect(nr.rects).toBeNull();
     expect(nr).toEqual(new testStructs.NamedRegion({}));
 
@@ -42,6 +41,39 @@ define([
     expect(e).toEqual(new testStructs.EmptyStruct({foo:123}));
   }
 
+  function testDefaultFieldValues() {
+    var s = new testStructs.DefaultFieldValues();
+    expect(s.f0).toEqual(false);
+
+    // f1 - f9, number type fields
+    for (var i = 1; i <= 8; i++)
+      expect(s["f" + i]).toEqual(0);
+
+    // f10,11 strings, f12-17 handles, f18-f21 arrays, f22,23 structs
+    for (var i = 10; i <= 23; i++)
+      expect(s["f" + i]).toBeNull();
+  }
+
+  function testExplicitFieldValues() {

[yzshen1, 2014/09/24 22:49:25]

nit: because we usually refer to "explicit field value" as "default value". In
order to avoid confusion, maybe we could consider "default" here and use
something such as "unspecified" for line 44?

[hansmuller, 2014/09/24 23:33:11]

OK. I've called the two structs and test functions: NoDefaultValues and
DefaultValues.

+    var s = new testStructs.ExplicitFieldValues();
+    expect(s.f0).toEqual(true);
+
+    // f1 - f11, number type fields
+    for (var i = 1; i <= 11; i++)
+      expect(s["f" + i]).toEqual(100);
+
+    // f12,13 "foo"
+    for (var i = 12; i <= 13; i++)
+      expect(s["f" + i]).toEqual("foo");
+
+    // f14,15 a default instance of Rect
+    var r = new rect.Rect();
+    expect(s.f14).toEqual(r);
+    expect(s.f15).toEqual(r);
+  }
+
   testConstructors();
+  testDefaultFieldValues();
+  testExplicitFieldValues();
   this.result = "PASS";
 });