public async Task PutSettings() { // Arrange var setting = new Dictionary <string, string>(); var controller = new ServerSettingsController(_service.Object); _service.Setup(m => m.UpdateSettingsAsync(setting, CancellationToken.None)) .ReturnsAsync(() => (new ModelStateDictionary(), setting)) .Verifiable(); // Act var result = await controller.Put(settings : setting); // Assert _service.Verify(); Assert.That(result, Has.Property(nameof(result.StatusCode)).EqualTo(200)); Assert.That(result, Has.Property(nameof(result.Value)).EqualTo(setting)); }