Moq：如何使用“复杂类型”参数模拟方法

Question

Original title:

Moq: Mocking method method with out parameter returns empty array

The problem was not with the out parameter but with the complex type parameter albumFilters of complex type AlbumFilter . See my Answer for details.

I have Moq working for a method without an out parameter but when I try and Moq with an out parameter it returns an empty array.

The GetAllAlbums_ok_returnsdata_test() passes. The GetAllAlbumsPaged_test() fails. The call to the _inventoryService in the GetAllAlbumsPaged method in the AlbumApiController returns an empty array Album[] .

I've looked at the Moq Quickstart section on using out arguments .

// out arguments

var outString = "ack";

// TryParse will return true, and the out argument will return "ack", lazy evaluated

mock.Setup(foo => foo.TryParse("ping", out outString)).Returns(true);

Test Class:

[Fact]
public void GetAllAlbums_ok_returnsdata_test() {
  Mock<IInventoryService> mockInventoryService
                      = new Mock<IInventoryService>();
  Album[] albums = { new Album { AlbumId = 1 },
    new Album { AlbumId = 2 } };
  mockInventoryService.Setup(obj => obj.GetAllAlbums()).Returns(albums);

  AlbumApiController controller = new AlbumApiController(mockInventoryService.Object);

  IHttpActionResult response = controller.GetAllAlbums();
  var contentResult = response as OkNegotiatedContentResult<Album[]>;
  Assert.NotNull(contentResult);
  Assert.NotNull(contentResult.Content);
  var data = contentResult.Content;
  Assert.Equal(data, albums); }

[Fact]
public void GetAllAlbumsPaged_test() {
  Mock<IInventoryService> mockInventoryService
                      = new Mock<IInventoryService>();
  Album[] albums = new Album[20];
    for (int i = 0; i < 20; i++) albums[i] = new Album { AlbumId = i + 1 };
  var albumFilter = new AlbumFilter { AlbumNumber = "", Artist = "",
      Title = "", Genre = 0, Price = 0, StockAmount = 0 };
  var sortItems = new List<SortItem>(); 
  int totalCount;

  mockInventoryService.Setup(obj => obj.GetAllAlbumsPaged(out totalCount, albumFilter,
        sortItems, 0, 4)).Returns(albums);

  AlbumApiController controller = new AlbumApiController(mockInventoryService.Object);

  IHttpActionResult response = controller.GetAllAlbumsPaged(Json.Encode(albumFilter),
        Json.Encode(sortItems), 0, 4);
  var contentResult = response as OkNegotiatedContentResult<object>;
  Assert.NotNull(contentResult); }

AlbumApiController:

public class AlbumApiController : ApiController
  {
    private readonly IInventoryService _inventoryService;

    public AlbumApiController(IInventoryService inventoryService)
    { _inventoryService = inventoryService; }

    [HttpGet]
    [Route("getallalbums")]
    public IHttpActionResult GetAllAlbums() {
      return GetHttpResponse(Request, () => {
        var albums = _inventoryService.GetAllAlbums();
        return Ok(albums); }); }


    [HttpGet]
    [Route("getallalbumspaged/{pageIndex}/{pageSize}")]
    public IHttpActionResult GetAllAlbumsPaged(string filters, string sorts,
          int pageIndex, int pageSize) { 
      var _filters = JsonConvert.DeserializeObject<AlbumFilter>(filters);
      var _sorts = JsonConvert.DeserializeObject<List<SortItem>>(sorts);
      return GetHttpResponse(Request, () => {
        int totalCount;
        var albums = _inventoryService.GetAllAlbumsPaged(out totalCount, _filters,
          _sorts, pageIndex, pageSize);
        var albums_Count = new { albums, totalCount };
        return Ok(albums_Count); }); } }

Update:

I added this test method to the AlbumAPIController :

[HttpGet]
public IHttpActionResult GetTest(int intTest)
{
  return GetHttpResponse(Request, () => {
    int testInt;
    var albums = _inventoryService.GetTest(out testInt, intTest);
    return Ok(albums);
  });
}

and this test to the test class:

[Fact]
public void GetTest_test() {
  Mock<IInventoryService> mockInventoryService
                = new Mock<IInventoryService>();
  Album[] albums = new Album[20];
  for (int i = 0; i < 20; i++) albums[i] = new Album { AlbumId = i + 1 };
  int testInt = 15;
  mockInventoryService.Setup(obj => obj.GetTest(out testInt, 5)).Returns(albums);

  AlbumApiController controller = new AlbumApiController(mockInventoryService.Object);
  IHttpActionResult response = controller.GetTest(5);
  var contentResult = response as OkNegotiatedContentResult<Album[]>;

  Assert.NotNull(contentResult);
  Assert.NotNull(contentResult.Content);
  var data = contentResult.Content;
  Assert.Equal(data, albums); }

The test passed and the testInt was updated in the GetTest method so the problem doesn't seem to be with the 'out parameter`.

Per Diana's troubleshooting suggestion I added this to the GetAllAlbumsPaged method (right after the JsonConverts ) to ensure the issue wasn't with the JSON .

  _filters = new AlbumFilter { AlbumNumber = "", Artist = "",
      Title = "", Genre = 0, Price = 0, StockAmount = 0 };
  _sorts = new List<SortItem>();

The call to the _inventoryService.GetAllAlbumsPaged method still returns an empty array, Albums[] .

Answer 1

The out parameter was not the problem. The complex type parameter AlbumFilter was the problem. Moq apparently didn't like the complex type . I was able to get it to work by changing the mockInventoryService setup by passing It.IsAny<AlbumFilter>() instead of the instance of the AlbumFilter , albumFilter .

 mockInventoryService.Setup(obj => obj.GetAllAlbumsPaged(out totalCount,
                      It.IsAny<AlbumFilter>(), sortItems, 0, 4)).Returns(albums);