Trying to mock a service with an HTTPClient

[Shreyans]

Hello,

I am currently trying to mock a service I have set up (let's call it ObjectService). It's fairly straightforward - I'm just trying to verify the user is authenticated, and then the response will return an object. This is roughly what it looks like:

private Object _object;

public virtual async Task<Object> GetObject(string token,string url)
{
    var client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
    var response = await client.GetStringAsync(url);
    client.Dispose();
    _object = JsonConvert.DeserializeObject<Object>(response);
    
    return _object;
}

I'm running into issues trying to use JustMock to mock this service.  What would be the best way for me to write a unit test for this? 

[Ivo]

Hello Shreyans,

I am sending a sample code that can be used for verification the value returned from the service. The unit test completely mocks the HTTP client, so the I am afraid that the authentication has to be verified in a different way using the real client and service. Here is a code:

[TestMethod]
public async Task GetObjectTest()
{
    // Aarrange
    var mockHttpService = Mock.Create<HttpClient>();
    var mockResponse =
        "{" +
        "   \"foo\":{" +
        "       \"id\": 10," +
        "       \"name\": \"bar\"" +
        "   }" +
        "}";

    var token = "secret";
    var url = "https://objectservice.org";

    Mock.Arrange(() => mockHttpService.GetStringAsync(url))
        .IgnoreInstance()
        .ReturnsAsync(mockResponse);
    Mock.Arrange(() => new AuthenticationHeaderValue("Bearer", token))
        .CallOriginal();
    Mock.SetupStatic(typeof(JsonConvert));

    // Act
    var sut = new ObjectService();
    var actual = await sut.GetObject(token, url);

    // Assert
    // TODO: verify the actual result from ObjectService.GetObject method call
    Mock.Assert(mockHttpService);
    Mock.Assert(() => JsonConvert.DeserializeObject<object>(mockResponse), Occurs.Once());
}

I hope the provided sample helps. Please let me know if you need further assistance.

Regards,
Ivo
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