ValuesControllerTest.cs

using HttpClientLab;
using Microsoft.AspNetCore.Mvc.Testing;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using Xunit;
using Xunit.Abstractions;

namespace Api.IntegrationTests
{
    public class ValuesControllerTest : IClassFixture<WebApplicationFactory<Startup>>
    {
        private readonly ITestOutputHelper _output;
        private readonly WebApplicationFactory<Startup> _factory;

        public ValuesControllerTest(ITestOutputHelper output, WebApplicationFactory<Startup> factory)
        {
            _output = output;
            _factory = factory;
        }

        [Fact]
        public async Task SetupDefaultBehaviourOfSpecificClient()
        {
            // Arrange
            var client = _factory
                .WithHttpClientBehaviour(out var httpClientBehaviour)
                .CreateClient();

            var gitHubClientBehaviour = httpClientBehaviour
                .SetupForClient("GitHubClient")  // or .SetupForClient<GitHubClient> or .SetupForAnyClient()
                .ForRequest(req => req.Method == HttpMethod.Get)  // direct access to the HttpRequestMessage
                // or .ForAnyRequest()
                .Returns(new HttpResponseMessage(HttpStatusCode.OK)  // return simply a HttpResponseMessage
                {
                    Content = new StringContent("Hello world!")
                });

            // Act
            var response = await client.GetAsync("/sample");

            // Print all http requests to get helpful info on failure
            httpClientBehaviour.WriteHttpRequests(_output);

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var content = await response.Content.ReadAsStringAsync();
            Assert.Equal("Hello world!", content);
        }

        [Fact]
        public async Task SetupDifferentBehaviours()
        {
            // Arrange
            var client = _factory
                .WithHttpClientBehaviour(out var httpClientBehaviour)
                .CreateClient();

            var gitHubClientBehaviour = httpClientBehaviour.SetupForClient<GitHubClient>();

            gitHubClientBehaviour
                .ForRequest(req => req.Method == HttpMethod.Get)
                .Returns(new HttpResponseMessage(HttpStatusCode.OK)
                {
                    Content = new StringContent("Hello world!")
                });
            gitHubClientBehaviour
                .ForRequest(req => req.Method == HttpMethod.Post)
                .Returns(new HttpResponseMessage(HttpStatusCode.Accepted));

            // Act
            var getResponse = await client.GetAsync("/sample");
            var postResponse = await client.PostAsync("/sample", null);

            // Print all http requests to get helpful info on failure
            httpClientBehaviour.WriteHttpRequests(_output);

            // Assert
            Assert.Equal(HttpStatusCode.OK, getResponse.StatusCode);
            Assert.Equal(HttpStatusCode.Accepted, postResponse.StatusCode);
        }
    }
}