public void TestDirty()
{
Document dm = new Document();
Assert.IsFalse(dm.Dirty);
dm.Text = "abc";
Assert.IsTrue(dm.Dirty);
dm.FileName = @"c:\abc.wordo";
DynamicMock fs = new DynamicMock(typeof (IFileSystem));
dm.Save((IFileSystem)fs.MockInstance);
Assert.IsFalse(dm.Dirty);
dm.Text = "abc2";
Assert.IsTrue(dm.Dirty);
dm.Save((IFileSystem)fs.MockInstance);
Assert.IsFalse(dm.Dirty);
fs.ExpectAndReturn("ReadAllText", "abc3", @"c:\abc.wordo");
dm.Load((IFileSystem)fs.MockInstance);
Assert.AreEqual("abc3", dm.Text);
Assert.IsFalse(dm.Dirty);
}