public void TestAddDirectoryFail() { _mockStore1.Setup(x => x.Contains(_digest1)).Returns(false); _mockStore2.Setup(x => x.Contains(_digest1)).Returns(false); _mockStore2.Setup(x => x.AddDirectory("path", _digest1, _handler)).Throws(new IOException("Fake IO exception for testing")); _mockStore1.Setup(x => x.AddDirectory("path", _digest1, _handler)).Throws(new IOException("Fake IO exception for testing")); _testStore.Invoking(x => x.AddDirectory("path", _digest1, _handler)).ShouldThrow <IOException>(because: "Should pass through fatal exceptions"); }