Add tests for sk.object functions and sk.stateReflector.

js/tests/object.js

+describe('sk.object functions',
+  function() {
+    function testGetDelta() {
+      var test = function(o, d, expected) {
+        assert.deepEqual(sk.object.getDelta(o, d), expected);
+      }
+      test({}, {}, {});
+      test({a: "foo"}, {a: "foo"}, {});
+      var first = {};  // Ensure getDelta does not modify its arguments.
+      test(first, {a: "foo"}, {});
+      assert.deepEqual(first, {});
+      var second = {};  // Ensure getDelta does not modify its arguments.
+      test({a: "foo"}, second, {a: "foo"});
+      assert.deepEqual(second, {});
+      test({a: "foo"}, {a: "bar"}, {a: "foo"});
+      test({a: "foo", b: "bar"}, {a: true, c: "bar"}, {a: "foo", b: "bar"});
+      test(["one", 2, 3.0], [1, "2", 3], {'0': "one"});
+      test({a: undefined, b: NaN, c: null}, {a: true, b: true, c: true},
+           {a: undefined, b: NaN, c: null});
+      test({a: undefined, b: NaN, c: false}, {a: null, b: null, c: null},
+           {b: NaN, c: false});
+      var noop = function () {};
+      test({a: test, b: noop}, {a: test, b: function () {}}, {b: noop});
+    }
+
+    function testApplyDelta() {
+      var test = function(delta, o, expected) {
+        assert.deepEqual(sk.object.applyDelta(delta, o), expected);
+      }
+      test({}, {}, {});
+      test({}, {a: "foo"}, {a: "foo"});
+      var first = {a: "bar"};  // Ensure applyDelta does not modify its arguments.
+      test(first, {a: "foo"}, {a: "bar"});
+      assert.deepEqual(first, {a: "bar"});
+      var second = {a: "bar"};  // Ensure applyDelta does not modify its arguments.
+      test({a: "foo"}, second, {a: "foo"});
+      assert.deepEqual(second, {a: "bar"});
+      test({a: "foo"}, {a: "bar", b: "baz"}, {a: "foo", b: "baz"});
+      test({a: "foo", b: "baz"}, {a: "bar"}, {a: "foo"});
+      test({a: "foo", b: "bar"}, {a: true, c: "bar"},
+           {a: "foo", c: "bar"});
+      test(["one"], [1, "2", 3], {'0': "one", '1': "2", '2': 3});
+      test({b: NaN, c: false}, {a: null, b: null, c: null},
+           {a: null, b: NaN, c: false});
+    }
+
+    it('should be able get differences and apply differences', function() {
+      testGetDelta();
+      testApplyDelta();
+    });
+  }
+);