2009-06-19 Mocking log4net calls

2009-06-19 mocking-log4net-calls

# Title: Mocking log4net calls
# Author: Mikael Lundin
# Link: http://blog.mikaellundin.name/2009/06/19/mocking-log4net-calls.html

RetrieveCustomer.cs

public Customer RetrieveCustomer(Guid id)
{
    Customer result = null;

    try
    {
        result = dataAccess.GetCustomerByID(id);
    }
    catch (DbException ex)
    {
        Log.Error("An exception was thrown from the database", ex);
    }

    return result;
}

Test.cs

[TestMethod]
public void ShouldSwallowDbExceptionButLogError()
{
    /* Setup */
    var exception = new TestDbException();

    var da = MockRepository.GenerateStub<DAL.CustomerDataAccess>();
    ILog log = MockRepository.GenerateStub<ILog>();
    var repository = new CustomerRepository(da, log);

    /* Arrange */
    da.Stub(dataAccess => dataAccess.GetCustomerByID(Arg<Guid>.Is.Anything))
        .Throw(exception);

    /* Act */
    repository.RetrieveCustomer(Guid.Empty);

    /* Assert */
    log.AssertWasCalled(logger => 
        logger.Error(Arg<string>.Is.Anything, Arg<Exception>.Is.Same(exception)));
}