
HarryDeveloper
Programming Kotlin: Issues in async() unit test (369, 370)
Hi sir,
I request your help with the below issue I came across while learning about unit testing.
I replicated the unit test example with name ‘getAirportStatus calls getAirportData asynchronously’ in the book, and I got the below error when I run the test
Can’t instantiate proxy for class kotlinx.coroutines.Deferred
io.mockk.MockKException: Can’t instantiate proxy for class kotlinx.coroutines.Deferred
I have a couple of questions regarding unit testing:
- What causes the above error? What does “Can’t instantiate proxy” actually mean?
- It is mentioned earlier in the book ‘suspend’ method calls must be done in coroutine context in the unit test, i.e, within runBlocking{}. How come getAirportStatus() method, a suspend method, is called without a runBlocking in the above test? What influence does ‘coEvery’ has on this aspect?
Kindly advise.
Thanks,
Harry
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