Checking arguments passed to mocked object methods

Hi knst,

You are using the method redirection pattern (we call it duck-type swapping internally), which is a valid way to solve many testing scenarios but a bit verbose. Most scenarios can be solved with the simpler mechanisms provided by Isolate.WhenCalled().

What are you trying to test in the code you posted? What you seem to be verifying is that the code you redirected to is working properly, i.e. verifying that Isolator is doing its job when redirecting... What would you like to verify in the code under test?

Doron
Typemock Support

I'm testing DAO and capturing DbCommand instance it uses to push data to DB (DB is mocked). Scenario I need is
- Create business object
- Call DAO.Insert(bo)
- Catch SqlCommand instance and check that it's params are correctly populated
- Prevent call to DB.

hi

have you tried using the Verify.WasCalledWithExactArguments()?

something in the spirit of:

object param = new object();
obj.DoIt(param)
Isolate.Verify.WasCalledWithExactArguments(()=>obj.DoIt(param));

Looks like I failed to explain what i need.
The SqlCommand is initilized in private code of DAO, I need to check that it is populated with correct params and CommandText.
I do not like to add any public methods to DAO returning SqlCommand as it is required only in tests (Internal method and InternalsVisibleTo also not very good option ).
It would be nice to not only mock method, but also be able to execute Assert against it's params.

WasCalledWithExactArguments compares passed arguments with provided instances, while i need to get the instance of provided argument and explore it and there is no way to provide the value for it to be compared with.

Hi,

lets see if i understood you correctly.
Is this more or less what you are doing?

public class BusinessObject
{
    public int CustomerID {get;set;}
    public string CompanyName { get; set; }
}

public class DAO
{
    public static void Insert(BusinessObject data)
    {
        using (SqlConnection connection = new SqlConnection("Some connection string"))
        {
            connection.Open();

            string queryString = String.Format("INSERT INTO Customers (CustomerID, CompanyName) Values('{0}', '{1}')",
                data.CustomerID,data.CompanyName);

            SqlCommand command = new SqlCommand(queryString, connection);
            command.ExecuteNonQuery();
        }

    }
}

if this is the case then heres a way to check that the proper string is passed to the SqlCommand ctor.
(I would have done it in the AAA syntax but I'm not sure they have the ability to verify arguments on the constructor)

[TestMethod]
[VerifyMocks]
public void DaoExample()
{
    string ExpectedSQLString = "INSERT INTO Customers" + 
        " (CustomerID, CompanyName) Values('6', 'yahoo')";
    using (RecordExpectations rec = new RecordExpectations())
    {
        using (SqlConnection connection = new SqlConnection("Some connection string"))
        {
            connection.Open();

            SqlCommand fake = new SqlCommand("", null);
            rec.CheckArguments(ExpectedSQLString, Check.IsAny());
            fake.ExecuteNonQuery();
            rec.Return(6);
        }
    }


    BusinessObject data = new BusinessObject();
    data.CustomerID = 6;
    data.CompanyName = "yahoo";

    DAO.Insert(data);
}

close but not exact :) you are testing the arguments of SqlCommand constructor. While I need to validate the SqlCommand object that DAO passes to DB (parameters , timeout, commandText etc).
In the sample i provided in my first post it is achieved (I'm using EntLib and mocking DataBase.ExecuteNonQuery method intercepting the DbCommand instance passed to it as param).
I was looking for some short way to achieve the same. Looks like it does not exist.
Anyway thanks for your help :)