Unittest case in C#

Question

How to write a test case for Getasync() with mockdata return type is Task

Amit Mohanty · Answer

Assuming you're using NUnit for testing. Here's an example of how to write a test case for a method that uses GetAsync() to retrieve data from a service with a Task return type: using NUnit.Framework; using Moq; //Assuming you have a class that retrieves data from a service: public class DataService { public async Task GetDataAsync(string url) { using (HttpClient client = new HttpClient()) { HttpResponseMessage response = await client.GetAsync(url); return await response.Content.ReadAsStringAsync(); } } } Now, let's write a test case that uses mock data to simulate the response from the service: [TestFixture] public class DataServiceTests { private Mock _mockHttpMessageHandler; private HttpClient _httpClient; private DataService _dataService; [SetUp] public void SetUp() { _mockHttpMessageHandler = new Mock (); _httpClient = new HttpClient(_mockHttpMessageHandler.Object); _dataService = new DataService(); } [Test] public async Task GetDataAsync_ReturnsData() { //Arrange string mockData = "Mock data response"; string url = "http://example.com"; HttpResponseMessage httpResponse = new HttpResponseMessage(); httpResponse.Content = new StringContent(mockData); httpResponse.StatusCode = HttpStatusCode.OK; _mockHttpMessageHandler.Protected() .Setup >("SendAsync", ItExpr.IsAny (), ItExpr.IsAny ()) .ReturnsAsync(httpResponse); //Act string data = await _dataService.GetDataAsync(url); //Assert Assert.AreEqual(mockData, data); } } Here we're using Moq to create a mock HttpMessageHandler , which we'll use to simulate the response from the service. We then set up the mock to return the expected response when the HttpClient makes a call to SendAsync() . Finally, we call the GetDataAsync() method and verify that it returns the expected data.