public void HashRequires_AllArguments() { var hashMock = new Mock <HashAlgorithm>(); var ex1 = Assert.Throws <ArgumentNullException>(() => ByteArrayExtensions.Hash(null, hashMock.Object)); var ex2 = Assert.Throws <ArgumentNullException>(() => new byte[0].Hash(hashMock.Object)); var ex3 = Assert.Throws <ArgumentNullException>(() => new byte[1].Hash(null)); Assert.Equal("bytes", ex1.ParamName); Assert.Equal("bytes", ex2.ParamName); Assert.Equal("algorithm", ex3.ParamName); }