<@U0MMYM2A3> as far as I understnad, extension fun...
# announcementsa
a_wer1986
06/09/2016, 8:12 AM@aaverin as far as I understnad, extension function will be compiled in the static helper method with first parameter - instance of MyClass.
I don't see any reason to test that ext.function is called on target instance of correct class, you will check compiler but not your code. if you do wrong (call on instance of other class), it must be compile error.
if I do, I will create a test instance of target class (or mock exists), import ext.function to test, call it and check result.
P.S. may be I misunderstood the question, but I see it this way.