ReturnsAsync in Moq is not working - asp.net-mvc

Question

Here is my code
public interface IUserManager
{
Task<int> PostUser(User user);
IQueryable<User> GetUserById(long userId);
}
public class UserManager : IUserManager
{
public UserManager(DataContext context)
{
this.DataContext = context;
}
public async Task<int> PostUser(User user)
{
this.DataContext.User.Add(user);
return await this.DataContext.SaveChangesAsync().ConfigureAwait(false);
}
public IQueryable<User> GetUserById(long userId)
{
return this.DataContext.User
.Where(userNotes => userNotes.UserId == userId).AsQueryable();
}
}
Controller:
public class UserController : BaseController
{
private readonly IUserManager userManager;
public UserController()
{
this.userManager = new UserManager();
}
public UserController(IUserManager userManager)
{
this.userManager = userManager;
}
[EnableQuery]
public IQueryable<User> Get([FromODataUri]long userId)
{
return this.userManager.GetUserById(userId);
}
public HttpResponseMessage Post(User user)
{
if (userNote == null || !ModelState.IsValid)
{
return this.BuildErrorResponse(ResponseCodes.INVALID_MISSING_INPUTS);
}
if (this.userManager.PostUser(user).Result <= 0)
{
return this.BuildErrorResponse(ResponseCodes.USER_ADD_FAILED);
}
return this.BuildSuccessResponse<User>(ResponseCodes.USER_ADDED, user);
}
}
Moq test:
[TestClass]
public class UnitTest
{
IUserManager userManagerMock;
Mock<IUserManager> iUserManagerMock;
[TestInitialize]
public void Setup()
{
//.. setup variables and mock data
userManagerMock = new UserManager(ContextMock.Object);
iUserManagerMock.Setup(u => u.PostUser(It.IsAny<User>()))
.ReturnsAsync(1);
}
[TestMethod]
public void Post()
{
var controller = new UserController(userManagerMock); //userNotesManagerMock will have the mock data //and mock methods setup
var httpResponse = controller.Post(userPostMock); //userPostMock will have mock data to save
//Assert.AreEqual(HttpResponseMessage, result);
}
}
I wrote a post method as you'd see here. I've a Get method as well which is working perfectly with mocking data.
But when I debug through the Post, the data the following statement is always returns ZERO instead of 1, which I've set up in the ReturnsAsync.
this.userManager.PostUser(user).Result <= 0 //this always gives me zero
What's wrong with the post ? Am I doing anything wrong ?
Can anyone shed some light on this
EDIT
Here is the GET version of the Test method and setup
[TestInitialize]
public void Setup()
{
//dummy data setup
UserMock = new List<User>
{
new User { //blah blah properties }
}.AsQueryable();
//context setup
dbSetUserMock = new Mock<IDbSet<User>>();
dbSetUserMock.Setup(m => m.Provider).Returns(UserMock.Provider);
dbSetUserMock.Setup(m => m.Expression).Returns(UserMock.Expression);
dbSetUserMock.Setup(m => m.ElementType).Returns(UserMock.ElementType);
dbSetUserMock.Setup(m => m.GetEnumerator()).Returns(UserMock.GetEnumerator());
UserContextMock = new Mock<DataContext>();
UserContextMock.Setup(s => s.User).Returns(dbSetUserMock.Object);
//inject the context to manager
UserManagerMock = new UserManager(UserContextMock.Object);
iUserManagerMock = new Mock<IUserManager>();
iUserManagerMock.Setup(notes => notes.PostUserNote(It.IsAny<User>()))
.ReturnsAsync(1);
}
[TestMethod]
public void Get_User_Success()
{
var controller = new UserController(UserManagerMock);
var values = controller.Get(100);
Assert.AreEqual(100, values.FirstOrDefault().UserId);
}
Get_User_Success works well now with the dummy data set and I'm able to pass the test without iUserManagerMock object. Reason being I want to execute the code inside of GetUser() method in Manager class.
And I've another question over here. As I'm setting the expected result to be 1 in the ReturnAsync for Post action. How do I build a test method for failure case scenario as the return from the POST method will still be 1 for failure case ?

Answer 1

You are mixing up the set up. If the method under test is the UserController.Post and you want to mock the UserManager via the IUserManager interface, then you don't need to new one up manually.
[TestClass]
public class UnitTest {
[TestMethod]
public void UserController_Should_Post_User_Ok() {
//Arrange
var userPostMock = new User { UserId = 100 };
var userManagerMock = new Mock<IUserManager>();
userManagerMock.Setup(u => u.PostUser(It.IsAny<User>())).ReturnsAsync(1);
var controller = new UserController(userManagerMock.Object);
controller.Request = new HttpRequestMessage();
controller.Configuration = new HttpConfiguration();
//Act
var httpResponse = controller.Post(userPostMock);
//Assert
Assert.AreEqual(System.Net.HttpStatusCode.OK, httpResponse.StatusCode);
}
[TestMethod]
public void UserController_Should_Post_User_Fail() {
//Arrange
var userPostMock = new User { UserId = 100 };
var userManagerMock = new Mock<IUserManager>();
userManagerMock.Setup(u => u.PostUser(It.IsAny<User>())).ReturnsAsync(0);//Replicating a failed post
var controller = new UserController(userManagerMock.Object);
controller.Request = new HttpRequestMessage();
controller.Configuration = new HttpConfiguration();
//Act
var httpResponse = controller.Post(userPostMock);
//Assert
Assert.AreEqual(System.Net.HttpStatusCode.InternalServerError, httpResponse.StatusCode);
}
[TestMethod]
public void UserManager_Should_Get_User_Success() {
//Arrange
var userMock = new List<User>
{
new User (){ UserId=100 }
}.AsQueryable();
//context setup
var dbSetUserMock = new Mock<IDbSet<User>>();
dbSetUserMock.Setup(m => m.Provider).Returns(userMock.Provider);
dbSetUserMock.Setup(m => m.Expression).Returns(userMock.Expression);
dbSetUserMock.Setup(m => m.ElementType).Returns(userMock.ElementType);
dbSetUserMock.Setup(m => m.GetEnumerator()).Returns(userMock.GetEnumerator());
var userContextMock = new Mock<DataContext>();
userContextMock.Setup(s => s.User).Returns(dbSetUserMock.Object);
//inject the context to manager
var userManagerMock = new UserManager(userContextMock.Object);
//Act
var values = userManagerMock.GetUserById(100);
//Assert
Assert.AreEqual(100, values.FirstOrDefault().UserId);
}
}