OCMock an NSOperation

Question

I am trying to write some Unit Tests to test some custom `NSOperations` that we are writing. What I'd like to do is create a Mock of the `NSOperation` and put it on the `NSOperationQueue`, and then wait for it to finish. I know I can swizzle the methods and not use `OCMoc`k at all, but I really don't want to do that. I'd like to use `OCMock`. The code I'm trying to run is something like the following: ``` MYOperation *operation = [MYOperation new]; id mockOperation = [OCMockObject partialMockForObject:operation]; [NSOperationQueue *queue = [NSOperationQueue new]; [queue setMaxConcurrentOperationCount:1]; [queue addOperation:mockOperation]; ``` When the unit test gets to this line: ``` [queue addOperation:mockOperation]; ``` I get a call to a deallocated object exception. Anyone have any suggestions on how I can overcome this?

Accepted Answer

If you're using ARC, `operation` is probably released right after you create the mock, as it's not accessed again. If you change it to this, it should fix the error:

```
[queue addOperation:operation];
```

...which you should be doing anyways--you're testing your object, not the mock.

OCMock an NSOperation

Solution

Problem