public async Task ThenIShouldReturnCorrectOrganisations() { var response = new SearchOrganisationsResponse { Organisations = new List <Organisation> { new Organisation() } }; var searchTerm = "Test"; var maximumResults = 500; _mediator.Setup(x => x.SendAsync(It.Is <SearchOrganisationsQuery>(y => y.SearchTerm == searchTerm && y.MaximumResults == maximumResults))).ReturnsAsync(response); //Act var result = await _controller.SearchOrganisations(searchTerm, maximumResults) as OkNegotiatedContentResult <IEnumerable <Organisation> >; //Assert Assert.IsNotNull(result); Assert.AreEqual(response.Organisations, result.Content); }