How to mock an SqlDataReader using Moq - Update

Question

I\'m new to moq and setting up mocks so i could do with a little help. How do I mock up an SqlDataReader using Moq?

Update

After further testing this is what I h

Answer 1

This does not let you mock a SqlDataReader but if your function is returning a DbDataReader (The base class of SqlDataReader) or a IDataReader the easist way to mock it is just use a DataTable or a DataSet and call its CreateDataReader() function and return that.

First, in a separate project, run your query like normal to produce some test data and use the WriteXmlSchema to generate a .xsd file and the WriteXml functions to hold the test data.

using (var con = new SqlConnection(connectionString))
{
    con.Open();
    using (var cmd = new SqlCommand("Some query", con))
    {

        DataSet ds = new DataSet("TestDataSet");
        DataTable dt = new DataTable("FirstSet");
        ds.Tables.Add(dt);
        using (var reader = cmd.ExecuteReader())
        {
            dt.Load(reader);
        }

        ds.WriteXmlSchema(@"C:\Temp\TestDataSet.xsd");
        ds.WriteXml(@"C:\Temp\TestDataSetData.xml");
    }
}

In your test project add TestDataSet.xsd to the project and make sure it has the custom tool of MSDataSetGenerator (it should have it by default). This will cause a DataTable derived class named TestDataSet to be generated that has the schema of your query.

Then add TestDataSetData.xml as a resource to your test project. Finally in your test create the TestDataSet and call ReadXml using the text from the xml file you generated.

var resultSet = new TestData.TestDataSet();
using (var reader = new StringReader(Resources.TestDataSetData))
{
    resultSet.ReadXml(reader);
}

var testMock = new Mock();

testMock.Setup(x => x.ExecuteReader())
    .Returns(resultSet.CreateDataReader);

testMock.Setup(x => x.ExecuteReaderAsync())
    .ReturnsAsync(resultSet.CreateDataReader);

This will create a data reader that will act just like the data reader that would have been returned from the sql query and even supports things like multiple result sets returned.