public void GetFullHostName_Combines_HostNameAndEmptyDomain_Correctly() { var dnsStatic = new DnsStatic(_mockNetworkData); var expectedHostname = dnsStatic.GetHostName(); Mock.Arrange(() => _mockNetworkData.GetDomainName(Arg.IsAny <INetworkInterfaceData>())).Returns(EmptyDomainName); // ACT var actualHostname = dnsStatic.GetFullHostName(); Assert.That(actualHostname, Is.EqualTo(expectedHostname)); }