How to test Ok() result using MStest in ASP.NET Core project

Question

I'm using MStest for testing my controllers.

I want to test this action:

[HttpGet(Name = "GetGroups")]
public async Task<IActionResult> Get()
{
    var groups = await _unitOfWork.Repository<Groupe>().GetAllAsync();
    var groupsDto = Mapper.Map<IEnumerable<GroupDto>>(groups);
    if (groupsDto.Count() == 0)
    {
        return NotFound();
    }
    return Ok(groupsDto);
}

One of the test for this action looks like that:

[TestMethod]
public async Task Group_Get_Should_Return_InstanceOfTypeOkNegotiatedContentResultIEnumerableGroupDto()
{
    // Arrange
    moqGroupRepository.Setup(g => g.GetAllAsync(null)).ReturnsAsync(groups).Verifiable();
    moqUnitOfWork.Setup(x => x.Repository<Groupe>()).Returns(moqGroupRepository.Object);

    var controller = new GroupController(moqUnitOfWork.Object);

    // Act
    var actionResult = await controller.Get() as OkNegotiatedContentResult<IEnumerable<GroupDto>>;

    // Assert
    Assert.IsInstanceOfType(actionResult, typeof(OkNegotiatedContentResult<IEnumerable<GroupDto>>));
}

The problem here is OkNegotiatedContentResult is unknown in ASP.Net Core project test.

What should I use to test Ok() result?

Answer 1

The probleme here is OkNegotiatedContentResult is unknow in asp net core project test What should i use to test Ok() result?

You could fix the problem by installing Microsoft.AspNetCore.Mvc NuGet package where implementations of IActionResult are defined.

However ASP.NET Core does not contain OkNegotiatedContentResult type, it's from ASP.NET Web API. In ASP.NET Core Controller.Ok() method returns the instance of OkObjectResult type.

You also have inconsistent checks in these two statements:

var actionResult = await controller.Get() as OkNegotiatedContentResult<IEnumerable<GroupDto>>;
Assert.IsInstanceOfType(actionResult, typeof(OkNegotiatedContentResult<IEnumerable<GroupDto>>));

as operator will return null if object could not be cast to requested type. So you could replace the second check with the following:

Assert.IsNotNull(actionResult);

So the required steps are:

1. Install Microsoft.AspNetCore.Mvc NuGet package to your Test project.

2. Adjust the test code in the following way:

   // ...
   using Microsoft.AspNetCore.Mvc;
   
   [TestMethod]
   public async Task Group_Get_Should_Return_InstanceOfTypeOkNegotiatedContentResultIEnumerableGroupDto()
   {
       // Arrange
       moqGroupRepository.Setup(g => g.GetAllAsync(null)).ReturnsAsync(groups).Verifiable();
       moqUnitOfWork.Setup(x => x.Repository<Groupe>()).Returns(moqGroupRepository.Object);
   
       var controller = new GroupController(moqUnitOfWork.Object);
   
       // Act
       var actionResult = await controller.Get() as OkObjectResult;
   
       // Assert
       Assert.IsNotNull(actionResult);
       Assert.IsInstanceOfType(actionResult.Value, typeof(IEnumerable<GroupDto>));
   }