I am using Hangfire to schedule some jobs. All my jobs have a schedule date, so I'm using Schedule static extension method
public static string Schedule([NotNull] this IBackgroundJobClient client, [InstantHandle][NotNull] Expression<Action> methodCall, DateTimeOffset enqueueAt);
I want to unit test my methods, so that I can check that Hangfire is actually being triggered.
To do so, I've followed Hangfire's documentation on unit testing (https://docs.hangfire.io/en/latest/background-methods/writing-unit-tests.html) which suggests mocking IBackgroundJobClient and verifying on the only public Create method it has:
string Create([NotNull] Job job, [NotNull] IState state);
But I can see that for Schedule invocations, this is not being called, another overload that is not public is being called instead, so I get the following error:
Message: Moq.MockException :
Expected invocation on the mock at least once, but was never performed: x => x.Create(It.IsAny<job>(), It.IsAny<enqueuedstate>())
No setups configured.
Performed invocations:
IBackgroundJobClient.Create(JobService.TaskFunction, ScheduledState)
Nevertheless, I've made an attempt with Enqueue method, and that seems to work with the mock. But I need to use Schedule.
Another option would be to assert on the overload it is actually calling
public static string Create([NotNull] this IBackgroundJobClient client, [InstantHandle][NotNull] Expression<Action> methodCall, [NotNull] IState state);
But since it's an extension method, that's not a valid approach for Moq.
Message: System.NotSupportedException : Invalid verify on an extension method: x => x.Create(It.IsAny<Expression<Action>>(), It.IsAny<EnqueuedState>())
So how can I unit test Hangfire for Schedule method?
The example you refer to uses different extension method which at the end calls different IBackgroundJobClient method, github. The following method has been invoked:
client.Create(Expression<Action> methodCall, new EnqueuedState());
It perfectly fits the Verify within the example.
On the other hand, your are calling Schedule method, github. Schedule method at the end invokes the following:
client.Create(Expression<Action> methodCall, new ScheduledState(enqueueAt.UtcDateTime))
Which is also an expression method, so you need to dive deeper one more level where actual interface method has been called:
string Create([NotNull] Job job, [NotNull] IState state);
As you can see from the error itself your expectation doesn't match with the actual invocation:
Performed invocations:
IBackgroundJobClient.Create(JobService.TaskFunction, ScheduledState)
Your assert should be something like this:
// Assert
client.Verify(x => x.Create(
It.IsAny<Job>(), //you could as in example check actual method name
It.IsAny<IState>())); //you could check actual offset