CODEWITHSUNDEEP
c#unit-testingmoq
user2983192
user2983192

Reputation: 13

Testing a public class Method that takes an IQueryable parameter

I am new to C# and newer to testing. I have read several questions here and other pages online discussing unit testing with Moq, but I'm just not getting it.

The following is an expression I wish to test using a list of hard coded Readings.

public class RequiredStations
{
    //private readonly WundergroundEntities _database;

    public List<Reading> Stations(IQueryable<Reading> readingsList)
    {
        return readingsList.GroupBy(r => r.WeatherStationID)
                         .Select(grp => new Reading { WeatherStationID = grp.Key, Date_Taken = grp.Max(dt => dt.Date_Taken) })
                         .ToList();

    }
}

The following is my latest botched attempt at testing the above...

[TestClass]
public class RequiredStations_Tests
{
    [TestMethod]
    public void TestingWeatherStationsRequiredLinq()
    {
        IList<Reading> readings = new List<Reading>
            {
            new Reading { WeatherStationID = "1", ReadingID = 1, Reading_Date = new DateTime(01/01/2014), Date_Taken = new DateTime(01/01/2014), Avg_Temperature = 6, Max_Temperature = 8, Min_Temperature = 2},
            new Reading { WeatherStationID = "1", ReadingID = 2, Reading_Date = new DateTime(02/01/2014), Date_Taken = new DateTime(02/01/2014), Avg_Temperature = 1, Max_Temperature = 1, Min_Temperature = 1},
            new Reading { WeatherStationID = "1", ReadingID = 3, Reading_Date = new DateTime(03/01/2014), Date_Taken = new DateTime(03/01/2014), Avg_Temperature = 3, Max_Temperature = 3, Min_Temperature = 3},
            new Reading { WeatherStationID = "2", ReadingID = 4, Reading_Date = new DateTime(01/02/2014), Date_Taken = new DateTime(01/02/2014), Avg_Temperature = 8, Max_Temperature = 8, Min_Temperature = 8},
            new Reading { WeatherStationID = "2", ReadingID = 5, Reading_Date = new DateTime(01/03/2014), Date_Taken = new DateTime(01/03/2014), Avg_Temperature = 9, Max_Temperature = 9, Min_Temperature = 9},
            new Reading { WeatherStationID = "2", ReadingID = 6, Reading_Date = new DateTime(01/04/2014), Date_Taken = new DateTime(01/04/2014), Avg_Temperature = 11, Max_Temperature = 11, Min_Temperature = 11}

        };

        Mock<RequiredStations> requiredStations = new Mock<RequiredStations>();

Could someone please explain how I should create the list of readings, and then Mock the class & method. Or if this is completely the wrong way to go about it, please enlighten me?

Upvotes: 1

Views: 274

Answers (2)

Sam Holder
Sam Holder

Reputation: 32946

you have created your List<Readings>, I think you can just pass it to your method to be tested calling the AsQueryable() extension method on it.

something like this:

[TestMethod]
public void TestingWeatherStationsRequiredLinq()
{
    List<Reading> readings = new List<Reading>
        {
        new Reading { WeatherStationID = "1", ReadingID = 1, Reading_Date = new DateTime(01/01/2014), Date_Taken = new DateTime(01/01/2014), Avg_Temperature = 6, Max_Temperature = 8, Min_Temperature = 2},
        new Reading { WeatherStationID = "1", ReadingID = 2, Reading_Date = new DateTime(02/01/2014), Date_Taken = new DateTime(02/01/2014), Avg_Temperature = 1, Max_Temperature = 1, Min_Temperature = 1},
        new Reading { WeatherStationID = "1", ReadingID = 3, Reading_Date = new DateTime(03/01/2014), Date_Taken = new DateTime(03/01/2014), Avg_Temperature = 3, Max_Temperature = 3, Min_Temperature = 3},
        new Reading { WeatherStationID = "2", ReadingID = 4, Reading_Date = new DateTime(01/02/2014), Date_Taken = new DateTime(01/02/2014), Avg_Temperature = 8, Max_Temperature = 8, Min_Temperature = 8},
        new Reading { WeatherStationID = "2", ReadingID = 5, Reading_Date = new DateTime(01/03/2014), Date_Taken = new DateTime(01/03/2014), Avg_Temperature = 9, Max_Temperature = 9, Min_Temperature = 9},
        new Reading { WeatherStationID = "2", ReadingID = 6, Reading_Date = new DateTime(01/04/2014), Date_Taken = new DateTime(01/04/2014), Avg_Temperature = 11, Max_Temperature = 11, Min_Temperature = 11}
    };

    RequiredStations requiredStations = new RequiredStations();
    var result = requiredStations.Stations(readings.AsQueryable());
    //assert things about result here
}

if you don't see the AsQueryable() method then you might need to add this to your using statements:

using System.Linq;

Upvotes: 4

David
David

Reputation: 218960

There's nothing here to be mocked. The code being tested has no dependencies. It simply accepts a collection and returns a modified collection:

// arrange
IList<Reading> readings = new List<Reading>
{
    // build your hard-coded data
};
RequiredStations requiredStations = new RequiredStations();

// act
var result = requiredStations.Stations(readings);

// assert
// examine "result" to make sure it is what you expect

Upvotes: 3

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