CreditCheckerTestCase1.cs

[Fact]
public async void Given_One_or_More_Loan_Requests_Each_Is_Enriched_With_Credit_Score_Info()
{
    IReadOnlyCollection<LoanRequest> mockLoanRequests = MockData();
    ICreditCheckFilter creditCheckFilter = new CreditCheckFilter(
        new MockHttpMessageHandlerFactory());
    List<EnrichedLoanRequest> loanRequestsWithCreditReport =
        new List<EnrichedLoanRequest>();

    foreach (var mockLoanRequest in mockLoanRequests)
    {
        loanRequestsWithCreditReport.Add(await creditCheckFilter
        .PerformCreditCheck(mockLoanRequest));
    }

    Assert.True(loanRequestsWithCreditReport.Any());
    Assert.True(
        loanRequestsWithCreditReport.Count(x => x.CreditCheckReport != null) ==
        loanRequestsWithCreditReport.Count);
}

private IReadOnlyCollection<LoanRequest> MockData()
{
    return new[]
    {
        new LoanRequest
        {
            CitizenServiceNumber = "12345",
            RequestedLoanAmount = 1000.0m
        },
        new LoanRequest
        {
            CitizenServiceNumber = "12346",
            RequestedLoanAmount = 2000.0m
        }
    };
}

public class MockHttpMessageHandler
    : HttpMessageHandler
{
    protected override async Task<HttpResponseMessage> SendAsync(
        HttpRequestMessage request,
        CancellationToken cancellationToken)
    {
        HttpResponseMessage httpResponseMessage =
            new HttpResponseMessage();
        httpResponseMessage.Content =
             MockContent(request.Content);
        httpResponseMessage.StatusCode = HttpStatusCode.OK;

        return await Task.FromResult(httpResponseMessage);
    }

    private HttpContent MockContent(HttpContent content)
    {
        string mockJsonContent = "{\"BSN\":\"12345\", \"CreditRating\":\"A\", " +
            "\"Score\":\"9\", \"Status\":\"Good credit\"}";

        return new StringContent(
            mockJsonContent,
            Encoding.UTF8,
            "application/json");
    }
}

public class MockHttpMessageHandlerFactory
    : IHttpMessageHandlerFactory
{
    public Uri BaseUri =>
        new Uri("http://localhost:1111");

    public HttpMessageHandler Create() =>
        new MockHttpMessageHandler();
}