CODEWITHSUNDEEP
c#unit-testingtestinguwp
Kamil
Kamil

Reputation: 25

Unit testing, connection to api in UWP

Hi I have to write unit test to this method: 

public static async Task<TradeModel[]> LoadTrades(int limit = 300)
{
    string url = "";

    if (limit <= 300)
    {
        url = $"https://api.bitbay.net/rest/trading/transactions/BTC-PLN?limit={ limit }";
    }
    else
    {

    }

    using (HttpResponseMessage response = await ApiHelper.ApiClient.GetAsync(url))//exeption
    {
        if (response.IsSuccessStatusCode)
        {
            TradeItemModel trade = await response.Content.ReadAsAsync<TradeItemModel>();

            return trade.Items;
        }
        else
        {
            throw new Exception(response.ReasonPhrase);
        }
    }
}

And my unit test:

[TestMethod]
public async Task TestMethod1()
{
    List<int> numbers = new List<int> { 1, 26, 70, 5 };
    List<Type> expected = new List<Type> { typeof(TradeModel[]), typeof(TradeModel[]), typeof(TradeModel[]), typeof(TradeModel[]) };
    List<Type> actual = new List<Type>();

    for(int i= 0; i < 4; i++)
    {
        var trades = await TradeProcessor.LoadTrades(numbers[i]);
        actual.Add(trades.GetType());
    }

    CollectionAssert.AreEqual(expected, actual);
}

I don't understand why I get an exeption Object reference not set to an instance of an object. What am I doing wrong? How this test should look like?

Upvotes: 0

Views: 33

Answers (1)

user8276908
user8276908

Reputation: 1061

I received the same error when implementing a unit test for WPF. In WPF you have to run the control in an Apartment Thread. To do this, I've used NUnit and tagged every unit test class with [Apartment(ApartmentState.STA)]. Other Unit Test Frameworks should have similar ways of enforcing this Threading state...

    [Apartment(ApartmentState.STA)]
    public class ByteTests
    {
        [SetUp]
        public void Setup()
        {
        }

        [Test]
        public void TestValues()
        {
        }
}

Upvotes: 1

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