I've got an interface which declares
Task DoSomethingAsync();
I'm using MoqFramework for my tests:
[TestMethod()]
public async Task MyAsyncTest()
{
Mock<ISomeInterface> mock = new Mock<ISomeInterface>();
mock.Setup(arg => arg.DoSomethingAsync()).Callback(() => { <my code here> });
...
}
Then in my test I execute the code which invokes await DoSomethingAsync()
. And the test just fails on that line. What am I doing wrong?
Your method doesn't have any callbacks so there is no reason to use .CallBack()
. You can simply return a Task with the desired values using .Returns()
and Task.FromResult, e.g.:
MyType someValue=...;
mock.Setup(arg=>arg.DoSomethingAsync())
.Returns(Task.FromResult(someValue));
Update 2014-06-22
Moq 4.2 has two new extension methods to assist with this.
mock.Setup(arg=>arg.DoSomethingAsync())
.ReturnsAsync(someValue);
mock.Setup(arg=>arg.DoSomethingAsync())
.ThrowsAsync(new InvalidOperationException());
Update 2016-05-05
As Seth Flowers mentions in the other answer, ReturnsAsync
is only available for methods that return a Task<T>
. For methods that return only a Task,
.Returns(Task.FromResult(default(object)))
can be used.
As shown in this answer, in .NET 4.6 this is simplified to .Returns(Task.CompletedTask);
, e.g.:
mock.Setup(arg=>arg.DoSomethingAsync())
.Returns(Task.CompletedTask);