How can I mock a method that returns a Task<IList<>>?

Question

I am trying to unit test a method that returns a Task>:

void Main()
{
    var mockRepo = new Mock<IRepository>();
    mockRepo.Setup(x => x.GetAll()).Returns(new List<MyModel>() { new MyModel { Name = "Test" } });  // works

    mockRepo.Setup(x => x.GetAllAsync()).Returns(Task.FromResult(new List<MyModel>() { new MyModel { Name = "Test" } }));  // error

    var result = mockRepo.Object.GetAll();
    result.Dump();
}

public interface IRepository
{
    Task<IList<MyModel>> GetAllAsync();
    IList<MyModel> GetAll();
}

public class MyModel
{
    public string Name { get; set; }
}

But the Task returning method generates a compiler error:

CS1503 Argument 1: cannot convert from 'System.Threading.Tasks.Task<System.Collections.Generic.List<UserQuery.MyModel>' to 'System.Threading.Tasks.Task<System.Collections.Generic.IList<UserQuery.MyModel>'

What am I doing wrong?

Answer 1

You can use ReturnsAync method:

IList<MyModel> expected = new List<MyModel>() { new MyModel { Name = "Test" }};
mockRepo.Setup(x => x.GetAll()).ReturnsAsync(expected);

Answer 2

Posted to soon, found out that Moq has the ReturnsAsync method.

mockRepo.Setup(x => x.GetAllAsync()).ReturnsAsync((new List<MyModel>() { new MyModel { Name = "Test" } });  

Works fine.