Question

I have an object that reads data from an Excel file using, which takes a IDbConnection, IDbDataAdapter and an IDbCommand. I use the adapters fill method to populate a table with data, and this is how I am currently mocking it:

[TestCase]
public void TestReadCellsFromSpreadsheetReadsSuccessfully()
{
    var cells = new List<ReportData>
                    {
                        new ReportData { CellId = 1, ExcelCellLocation = "A1"},
                        new ReportData { CellId = 2, ExcelCellLocation = "A2"},
                        new ReportData { CellId = 3, ExcelCellLocation = "A3"},
                        new ReportData { CellId = 4, ExcelCellLocation = "A4"}
                    };

    _mockAdapter.Setup(a => a.Fill(It.IsAny<DataSet>()))
        .Callback((DataSet ds) =>
                      {
                          if (ds.Tables["Table"] == null)
                          {
                              ds.Tables.Add("Table");
                              ds.Tables["Table"].Columns.Add(new DataColumn());
                          }

                          var row = ds.Tables["Table"].NewRow();
                          row[0] = "Test";

                          ds.Tables["Table"].Rows.Add(row);
                      });

    var excelReader = new ExcelReader(_mockConnection.Object, _mockAdapter.Object, _mockCommand.Object);
    excelReader.ReadCellsFromSpreadsheet("Deal Summary", cells);

    _mockCommand.VerifySet(c => c.CommandText = It.IsAny<string>(), Times.Exactly(cells.Count));
    _mockAdapter.VerifySet(a => a.SelectCommand = _mockCommand.Object, Times.Exactly(cells.Count));
    _mockAdapter.Verify(a => a.Fill(It.IsAny<DataSet>()), Times.Exactly(cells.Count));
}

This implementation works, but I feel like I’m doing too much to Mock the adapter… is there a better way to do this?

Answer 1

Do not pass those 3 objects as parameters. Instead pass IDataReader, IDataProvider or sth like that that returns data. Then You just mock this object. And you don’t need reference to System.Data in project containing ExcellReader.

And two other things I don’t like about your code.
Why TestCase instead of Test?

Are you sure you want to create command and fill dataset for each column separately? (but maybe I don’t understand your code)