Error "Expected invocation on the mock once, but was 0 times" when unit testing with moq - unit-testing

Question

I have the following class I want to test:
public interface ISqlServiceByModule
{
DataSet GetPagedAggregateData(int clientId, int moduleId, int billTypeId, PagedTable result);
}
public class IncidentModuleService : IIncidentModuleService
{
private readonly ISqlServiceByModule sqlServiceByModule;
public IncidentModuleService(ISqlServiceByModule sqlServiceByModule)
{
if (sqlServiceByModule == null) throw new ArgumentNullException("sqlServiceByModule");
// Inject the ISqlServiceByModule dependency into the constructor
this.sqlServiceByModule = sqlServiceByModule;
}
public PagedTable GetData(int clientId, int moduleId, int billTypeId, Dictionary<string, string> queryStringParameters)
{
PagedTable result = new PagedTable(queryStringParameters);
DataSet dataSet = this.sqlServiceByModule.GetPagedAggregateData(clientId, moduleId, billTypeId, result);
// Map the DatSet to a PagedTable
if (dataSet == null || dataSet.Tables.Count == 0)
{
result.SetPagesFromTotalItems(0);
}
else
{
result.SetPagesFromTotalItems(Convert.ToInt16(dataSet.Tables[1].Rows[0][0]));
result.Listings = dataSet.Tables[0];
}
return result;
}
}
Specifically, I want to test the GetData method. My unit test looks like this:
[TestClass]
public class IncidentModuleServiceUnitTest
{
private DataSet incidentsData;
[TestInitialize]
public void SetUp()
{
this.incidentsData = new DataSet();
}
[TestMethod]
public void GetDataTestGetPagedAggregateDataIsCalled()
{
//-- Arrange
int billTypeId = 1;
int clientId = 1;
int moduleId = 1;
Dictionary<string, string> queryStringParameters = new Dictionary<string,string>();
PagedTable tempResult = new PagedTable(queryStringParameters);
DataSet dataSet = new DataSet();
dataSet.Tables.Add(new DataTable());
var mockSqlService = new Mock<ISqlServiceByModule>();
mockSqlService.Setup(r => r.GetPagedAggregateData(clientId, moduleId, billTypeId, tempResult)).Returns(this.incidentsData);
IncidentModuleService target = new IncidentModuleService(mockSqlService.Object);
//-- Act
var actual = target.GetData(clientId, moduleId, billTypeId, queryStringParameters);
//-- Assert
Assert.IsNull(actual.Listings);
mockSqlService.Verify(r => r.GetPagedAggregateData(clientId, moduleId, billTypeId, tempResult), Times.Once);
}
}
The error I am getting happens on the last line:
mockSqlService.Verify(r => r.GetPagedAggregateData(clientId, moduleId, billTypeId, tempResult), Times.Once);
And the exact error message is this:
{"\r\nExpected invocation on the mock once, but was 0 times: r =>
r.GetPagedAggregateData(.clientId, .moduleId, .billTypeId, .tempResult
Configured setups:\r\nr => r.GetPagedAggregateData(.clientId,
.moduleId, .billTypeId, .tempResult),
Times.Never
Performed invocations:\r\nISqlServiceByModule.GetPagedAggregateData(1,
1, 1, PagedTable)"}
Any idea why this is happening? It looks to me like the method in question is being called, but Moq doesn't like the parameters for some reason, even though they are the exact same ones in all three invocations, as far as I can tell.

Answer 1

PagedTable is a reference type not a value type. Therefore the parameters in Setup don't match what was called even though they look like they should be the same. You could use It.IsAny<PagedTable>() instead of tempResult.
See this answer for an example of how to check that the PagedTable parameter was the correct one.