public async Task AddDocumentAsync_ReturnsRegionDocumentDTO() { // Arrange RegionDocumentDTO doc = new RegionDocumentDTO() { ID = 2, BlobName = "Some, book", FileName = "Some.FileName" }; RegionDocuments regionDocuments = new RegionDocuments() { ID = 2, BlobName = "Some, book", FileName = "Some.FileName" }; _mapper.Setup(x => x.Map <RegionDocumentDTO, RegionDocuments>(doc)) .Returns(regionDocuments); _repoWrapper.Setup(x => x.RegionDocument.Attach(regionDocuments)); // Act var result = await _regionService.AddDocumentAsync(doc); // Assert Assert.IsInstanceOf <RegionDocumentDTO>(result); Assert.IsNotNull(result); }