public async Task AskServerForVersionsOfExistingPackageID() { var pkgService = new Mock <IPackageService>(MockBehavior.Strict); pkgService.Setup(p => p.FindAsync("abc", false, false)).ReturnsAsync(new Package[] { new Package() { Id = "abc", VersionString = "1.2.3" }, new Package() { Id = "abc", VersionString = "1.4.7" } }); using (TestServer server = TestServerBuilder.Create() .TraceToTestOutputHelper(Helper, LogLevel.Error) .WithMock(typeof(IPackageService), pkgService) .Build()) { var services = server.Host.Services; Assert.Equal(pkgService.Object, services.GetRequiredService <IPackageService>()); // https://docs.microsoft.com/en-us/nuget/api/package-base-address-resource#enumerate-package-versions var response = await server.CreateClient().GetAsync(string.Format(IndexUrlFormatString, "abc")); Assert.Equal(System.Net.HttpStatusCode.OK, response.StatusCode); var jsonString = await response.Content.ReadAsStringAsync(); var actual = JObject.Parse(jsonString); var expected = new JObject { { "versions", new JArray( "1.2.3", "1.4.7") } }; Assert.True(JToken.DeepEquals(expected, actual)); } }