Create a Partial Stub in Microsoft Moles - unit-testing

I am pulling my hair out with this one. I have looked and cannot find a simple, clear example of creating and using a partial stub with Microsoft Moles. Maybe I'm missing somethimg, or have my code architected poorly, but I can't seem to get this to work.
Here's my class (simplified):
public class AccountService : IAccountService {
private readonly webServiceProxy IExternalWebServiceProxy;
public AccountService(IExternalWebServiceProxy webServiceProxy) {
this.webServiceProxy = webServiceProxy;
}
public List<AccountModel> GetAccounts(string customerId) {
var returnList = new List<AccountModel>();
var xmlResponse = webServiceProxy.GetAllCustomerAccounts(customerId);
var accountNodes = xmlResponse.SelectNodes("//AccountNodes");
if (accountNodes != null)
{
foreach (XmlNode node in accountNodes)
{
var account = this.MapAccountFromXml(node);
if (!string.IsNullOrEmpty(account.AccountNumber))
{
returnList.Add(account);
}
}
}
return returnList;
}
public AccountModel MapAccountFromXml(XmlNode node) {
if (!IsValidAccount(node) {
return null;
}
// This performs a lot of XML manipulation getting nodes based on attributes
// and mapping them to the various properties of the AccountModel. It's messy
// and I didn't want it inline with the other code.
return populatedAccountModel;
{
public bool IsValidAccount(XmlNode node)
{
var taxSelectValue = node.SelectSingleNode("//FORMAT/Field[#taxSelect='1']").First().Value;
var accountStatus = // similar to first line in that it gets a single node using a specific XPath
var maturityDate = // similar to first line in that it gets a single node using a specific XPath
var maturityValue = // similar to first line in that it gets a single node using a specific XPath
return taxSelectValue != string.Empty && taxSelectValue != "0" && (accountStatusValue != "CL" || (maturityDate.Year >= DateTime.Now.AddYears(-1).Year));
}
}
What I want to do is test my GetAccounts() method. I can stub out the IExternalWebServiceProxy call and return fake XML, but I have internal calls happening in my service since my GetAccounts() method calls MapAccountFromXml() which in turn calls IsValidAccount().
Perhaps the solution is to not worry about breaking out the long and involved MapAccountFromXml() and IsValidAccount() code and just put them inline into the GetAccount() call, but I would rather leave them broken out for code readability.
I have my Moles assembly created, and know I can create a stub version of my class like this
var stubWebService = SIExternalWebServiceProxy {
GetAllCustomerAccounts = delegate {
return SomeHelper.GetFakeXmlDocument();
}
}
var stubAccountService = new SAccountService() { callsBase = true; }
My problem is I don't know how to then override the internal calls to MapAccountFromXml and IsValidAccount and I don't want my Unit Test to be testing thos methods, I'd like to isolate GetAccounts for the test. I read somewhere the methods need to be virtual to be overriden in a partial stub, but could not find anything that then showed how to create a stub that overrides a few methods while calling the base for the one I want to test.

Peer put me on the right track, thank you.
It turned out that what I was looking for is called Detours in Moles. Rather than stub an interface using
var stubAccountService = new SIAccountService();
what I needed to do was create an instance of my AccountService and then detour all calls to the methods I wanted to mock, like this
var accountService = new AccountService();
MAccountService.AllInstances.MapAccountFromXmlXmlNode = delegate {
return new AccountModel();
};
The MAccountService is provided by Moles when you Mole your assembly. The only missing piece to this is that for this to work you need to add the following attribute to your test method:
[HostType("Moles")]
This worked for me locally, but in the end I had trouble getting TFS to do automated builds
UPDATE
I just stumbled on another way of doing this, while looking at Rhino Mocks. If the methods in the class being mocked are virtual then you can override them in the mock, like this:
var accountService = new SAccountService();
accountService.MapAccountFromXmlXmlNode = delegate
{
return new AccountModel();
}
Now I can call
accountService.GetMemberAccounts();
and when accountService makes its call to MapAccountFromXml it will be caught by the stub and processed as I deem necessary. No messing with HostType and it works like a charm.

To test methods in you class in issolation you do this with moles by making a mole for the IsValidAccount and MapAccountFromXml methods. Or make a stub implementation with stubs where you let the stub call the orriginal methode using base. Or what I think is a nicer solution, make a test class which overrides the methods you do want to stub (this is the same what a stub would do, except you see all what is happening in your own code):
public class TestHelperAccountService : AccountService {
public override AccountModel MapAccountFromXml(XmlNode node) {
return new AccountModel(){
//Accountmodelstub
};
{
public override bool IsValidAccount(XmlNode node)
{
return true;
}
}
This way you can do your test for the GetAccount method on your TestHelperAccountService class where you GetAccount method runs in full issolation. You can do the same for the methods like MapAccountFromXml to test them seperatly.

Related

Stub setter in Rhino Mock partial mock

I'm following the accepted answer in this question but I'm getting a NullReferenceException.
What I need is having a partial mock stub a property (both getter and setter) to behave like a stub (as a simple automatic property). Currently I am able to stub the getter but not the setter.
Is this possible?
EDIT: this is a simple example, I hope it helps explaining my problem.
public class SomeClass
{
public virtual string SomeProperty
{
get{ return SomeMethodDependingOnDBOrAspSession(); }
set{ SomeMethodDependingOnDBOrAspSession(value); } // I want to avoid calling this setter implementation
}
}
var partialMock = MockRepository.GeneratePartialMock<SomeClass>();
partialMock.Stub(p => p.SomeProperty); // I want SomeProperty to behave as an automatic property
When using a PartialMock you can get auto-implemented property like behavior by using PropertyBehavior feature of Rhino Mocks. Given the class in your question, the following nunit test passes for me.
[Test]
public void TestPartialMock()
{
var someClass = MockRepository.GeneratePartialMock<SomeClass>();
someClass.Stub(x => x.SomeProperty).PropertyBehavior();
string val = "yo!";
Assert.DoesNotThrow(() => someClass.SomeProperty = val);
Assert.AreEqual(val, someClass.SomeProperty);
}
If you don't need a PartialMock you could use a Stub which has property behavior by default. You'd simply replace the first two lines of the test with:
var someClass = MockRepository.GenerateStub<SomeClass>();

mocking a method while calling a method in same service class groovy grails

im looking for something similar to what i would do with rhino mocks but in groovy.
i sometimes use partial mocks as well.
in ASP -- Rhino mocks
const string criteria = "somecriteriahere";
ISomeRepository mockSomeRepository = MockRepository.GenerateStrictMock<SomeRepository>();
mockSomeRepository.Expect(m => m.GetSomesByNumber(criteria)).Return(new List<Some>() { });
mockSomeRepository.Expect(m => m.GetSomesByName(criteria)).Return(new List<Some>() { });
mockSomeRepository.Expect(m => m.GetSomesByOtherName(criteria)).Return(new List<Some>() { });
mockSomeRepository.SearchForSomes(criteria);
mockSomeRepository.VerifyAllExpectations();
--------note the virtual -------
public class SomeRepository : ISomeRepository {
public virtual IEnumerable<Some> GetSomesByNumber(string num)
{
//some code here
}
public virtual IEnumerable<Some> GetSomesByName(string name)
{
//some code here
}
public virtual IEnumerable<Some> GetSomesByOtherName(string name)
{
//some code here
}
public IEnumerable<Some> SearchForSomes(string criteria) {
this.GetSomesByNumber(criteria); //tested fully seperatly
this.GetSomesByName(criteria); //tested fully seperatly
this.GetSomesByOtherName(criteria); //tested fully seperatly
//other code to be tested
}
}
GetSomesByNumber, GetSomesByName, GetSomesByOtherName would be tested fully seperatly. If i actually provided values and went into those functions, to me, that seems like in integration test where im testing multiple functionalities and not one unit of work.
So, SearchForSomes i would only be testing that method and mocking away all other dependencies.
In Grails
class XService {
def A() {
}
def B() {
def result = this.A()
//do some other magic with result
}
}
I have tried this -- but failed
def XServiceControl = mockFor(XService)
XServiceControl.demand.A(1..1) { -> return "aaa" }
// Initialise the service and test the target method.
//def service = XServiceControl.createMock();
//def service = XServiceControl.proxyInstance()
// Act
//def result = XServiceControl.B(_params);
XServiceControl.use {
new XService().B(_params)
}
Ive got no idea how to do this, does any one know how?
Thanks
If you're using groovy MockFor (e.g. groovy.mock.interceptor.MockFor), then you need to enclode the usage in a .use{} block.
However, it looks like you are calling mockFor from within a grails.test.GrailsUnitTestCase. In that case, there's no need for the .use{} block: the scope of the mock is the whole test.
thanks for your reply ataylor
seem what i was trying to accomplish is something called partial/half mocking. Here are some links.
http://www.gitshah.com/2010/05/how-to-partially-mock-class-and-its.html
http://mbrainspace.blogspot.com/2010/02/partial-half-mocks-why-theyre-good-real.html
https://issues.apache.org/jira/browse/GROOVY-2630
https://issues.apache.org/jira/browse/GROOVY-1823
http://java.dzone.com/articles/new-groovy-171-constructor
I didnt accomplish this, i ended up extracting B() into its own class and injecting a mock of XService into B's class -- Dependency Injection. I was also informed that extracting away dependencies is a better practice for testing. So, i am now very carefull when using this.() :D

Rhino Mocks - Mock a method call to Service inside a property

I am trying to test that the property gets it's value from the return of a Service call, but I am having trouble mocking the service call.
Here is my property:
public ICountry Country
{
get
{
if (_country == null)
{
ICountryService countryService = new CountryService();
_country = countryService.GetCountryForCountryId(_address.CountryId);
}
return _country;
}
}
Here is my attempt at testing this:
[TestMethod]
public void Country_should_return_Country_from_CountryService()
{
const string countryId = "US";
_address.CountryId = countryId;
var address = MockRepository.GenerateStub<Address>(_address);
var country = MockRepository.GenerateMock<ICountry>();
var countryService = MockRepository.GenerateStub<ICountryService>();
countryService.Stub(x => x.GetCountryForCountryId(countryId)).IgnoreArguments().Return(country);
Assert.AreEqual(address.Country, country);
}
I keep getting an error because the real countryService is being called, not my mock. I am using MsTest and Rhino Mocks. What am I doing wrong?
You problem is that the property is directly constructing the dependency. Due to this the mock service is not getting called, the actual real CountryService implementation is getting called.
A way around this might be to utilize constructor injection of a CountryService factory (or the service itself) in the other objects (Address?) constructor. This way you could get your fake CountryService (the mock) to be returned and be the one called by the method
For example:
private ICountryService _countryService;
//constructor
public OuterObject(ICountryService countryService)
{
//maybe guard clause
_countryService = countryService;
}
public ICountry Country
{
get
{
if (_country == null)
{
_country = _countryService.GetCountryForCountryId(_address.CountryId);
}
return _country;
}
}
You would need to then pass the mocked ICountryService into the other objects constructor in your unit test

How to mock HttpClientCertificate?

I am trying to unit test an action filter I wrote. I want to mock the HttpClientCertificate but when I use MOQ I get exception. HttpClientCertificate doesnt have a public default constructor.
code:
//Stub HttpClientCertificate </br>
var certMock = new Mock<HttpClientCertificate>();
HttpClientCertificate clientCertificate = certMock.Object;
requestMock.Setup(b => b.ClientCertificate).Returns(clientCertificate);
certMock.Setup(b => b.Certificate).Returns(new Byte[] { });
This is the most awkward case of creating unit testable systems in .NET. I invariable end up adding a layer of abstraction over the component that I can't mock. Normally this is required for classes with inaccessible constructors (like this case), non-virtual methods or extension methods.
Here is the pattern I use (which I think is Adapter pattern) and is similar to what MVC team has done with all the RequestBase/ResponseBase classes to make them unit testable.
//Here is the original HttpClientCertificate class
//Not actual class, rather generated from metadata in Visual Studio
public class HttpClientCertificate : NameValueCollection {
public byte[] BinaryIssuer { get; }
public int CertEncoding { get; }
//other methods
//...
}
public class HttpClientCertificateBase {
private HttpClientCertificate m_cert;
public HttpClientCertificateBase(HttpClientCertificate cert) {
m_cert = cert;
}
public virtual byte[] BinaryIssuer { get{return m_cert.BinaryIssuer;} }
public virtual int CertEncoding { get{return m_cert.CertEncoding;} }
//other methods
//...
}
public class TestClass {
[TestMethod]
public void Test() {
//we can pass null as constructor argument, since the mocked class will never use it and mock methods will be called instead
var certMock = new Mock<HttpClientCertificate>(null);
certMock.Setup(cert=>cert.BinaryIssuer).Returns(new byte[1]);
}
}
In your code that uses HttpClientCertificate you instead use HttpClientCertificateBase, which you can instantiate like this - new HttpClientCertificateBase(httpClientCertificateInstance). This way you are creating a test surface for you to plug in mock objects.
The issue is that you need to specify constructor parameters when creating the mock of the HttpClientCertificate.
var certMock = new Mock<HttpClientCertificate>(ctorArgument);
The bad news is that the ctor for HttpClientCertificate is internal and takes in an HttpContext, so it probably won't work.
Unless you want to write more code to make the class "Testable" I suggest you use Typemock Isolator, Unless specified otherwise it looks for the first c'tor available - public, internal or private and fake (mocks) it's parameters so you won't have to.
Creating the fake object is as simple as:
var fakeHttpClientCertificate = Isolate.Fake.Instance<HttpClientCertificate>();
Another alternative is to use the free Microsoft Moles framework. It will allow you to replace any .NET method with your own delegate. Check out the link as it gives an example that is pretty easy to understand. I think you'll find it much nicer than adding layers of indirection to get HttpClientCertificate into a testable state.

How to use Rhino Mock to mock a local function calling?

Here is my situation:
I want to test on the "HasSomething()" function, which is in the following class:
public class Something
{
private object _thing;
public virtual bool HasSomething()
{
if (HasSomething(_thing))
return true;
return false;
}
public virtual bool HasSomething(object thing)
{
....some algo here to check on the object...
return true;
}
}
So, i write my test to be like this:
public void HasSomethingTest1()
{
MockRepository mocks = new MockRepository();
Something target = mocks.DynamicMock(typeof(Something)) as Something;
Expect.Call(target.HasSomething(new Object())).IgnoreArguments().Return(true);
bool expected = true;
bool actual;
actual = target.HasSomething();
Assert.AreEqual(expected, actual);
}
Is my test written correctly?
Please help me as i can't even get the result as expected. the "HasSomething(object)" just can't be mock in that way. it did not return me 'true' as being set in expectation.
Thanks.
In response to OP's 'answer': Your main problem is that RhinoMocks does not mock members of classes - instead it creates mock classes and we can then set expectations and canned responses for its members (i.e. Properties and Functions). If you attempt to test a member function of a mock/stub class, you run the risk of testing the mocking framework rather than your implementation.
For the particular scenario of the logical path being dependent on the return value of a local (usually private) function, you really need an external dependency (another object) which would affect the return value that you require from that local function. For your code snippet above, I would write the test as follows:
[Test]
public void TestHasSomething()
{
// here I am assuming that _thing is being injected in via the constructor
// you could also do it via a property setter or a function
var sut = new Something(new object());
Assert.IsTrue(sut.HasSomething);
}
i.e. no mocking required.
This is one point of misunderstanding that I often had in the past with regards to mocking; we mock the behaviour of a dependency of the system under test (SUT). Something like: the SUT calls several methods of the dependency and the mocking process provides canned responses (rather than going to the database, etc) to guide the way the logic flows.
A simple example would be as follows (note that I have used RhinoMocks AAA syntax for this test. As an aside, I notice that the syntax that you are using in your code sample is using the Record-Replay paradigm, except that it isn't using Record and Replay! That would probably cause problems as well):
public class SUT
{
Dependency _depend
public SUT (Dependency depend)
{
_depend = depend;
}
...
public int MethodUnderTest()
{
if (_depend.IsReady)
return 1;
else
return -1;
}
}
...
[Test]
public void TestSUT_MethodUnderTest()
{
var dependency = MockRepository.GenerateMock<Dependency>();
dependency.Stub(d => d.IsReady).Return(true);
var sut = new SUT(dependency);
Assert.AreEqual(1, sut.MethodUnderTest());
}
And so the problem that you have is that you are attempting to test the behaviour of a mocked object. Which means that you aren't actually testing your class at all!
In a case like this, your test double should be a derived version of class Something. Then you override the method HasSomething(object) and ensure that HasSomething() calls your one.
If I understand correctly, you are actually interested in testing the method HasDynamicFlow (not depicted in your example above) without concerning yourself with the algorithm for HasSomething.
Preet is right in that you could simply subclass Something and override the behavior of HasSomething to short-circuit the algorithm, but that would require creating some additional test-dummy code which Rhino is efficient at eliminating.
Consider using a Partial Mock Stub instead of a Dynamic Mock. A stub is less strict and is ideal for working with Properties. Methods however require some extra effort.
[Test]
public void CanStubMethod()
{
Foo foo = MockRepository.GenerateStub<Foo>();
foo.Expect(f => f.HasDynamicFlow()).CallOriginalMethod(OriginalCallOptions.NoExpectation);
foo.Expect(f => f.HasSomething()).CallOriginalMethod(OriginalCallOptions.NoExpectation);
foo.Expect(f => f.HasSomething(null)).IgnoreArguments().Return(true);
Assert.IsTrue(foo.HasDynamicFlow());
}
EDIT: added code example and switched Partial Mock to Stub