Unit Test - Assert object returned by a controller action

Question

How can I check if the value returned as part of that OkObjectResult has a count of 2 without changing any code in the controller action?

Here is my controller action

public IActionResult GetUserNames()
{
    var users = _repository.GetUsers();
    return Ok(users.Select(u => u.Name));
}

My unit test looks like this

[Fact]
public void GetUserNames_ValidRequest_ShouldReturnOk()
{
    _repository
        .Setup(r => r.GetUsers())
        .Return(new List<User> 
            {
                new User { Name = "SomeRandomName" },
                new User { Name = "SomeRandomName2" }  
            });

    var result = _controller.GetUserNames();

    result.Should().BeOfType<OkObjectResult>();
    // Code to check if 2 names are returned
}

I am using Mock and FluentAssertions in my unit test.

Answer 1

You should be able to do something like this:

var objectResult = Assert.IsType<OkObjectResult>(result);
var model = Assert.IsAssignableFrom<List<string>>(objectResult.Value);
Assert.Equal(2, model.Count);