How do you mock out private properties with OCMock for iOS?

Question

I have a private property that is declared in the .m file of my class to be tested, let's call it ClassUnderTest. ClassUnderTest instantiates an instance of ClassToBeMocked. How do I use OCMock to mock out an instance of the ClassToBeMocked and assign it to the ClassUnderTest?

Possible duplicate of https://stackoverflow.com/questions/34571/how-do-i-test-a-class-that-has-private-methods-fields-or-inner-classes — Raedwald, Dec 14 '17 at 13:02

score 51 · Accepted Answer · answered Aug 10 '12 at 16:59

51

Re-declare the property in your test class. You can do the same for private methods. In ClassUnderTestTest.m:

@interface ClassUnderTest ()

@property(retain)ClassToBeMocked *instanceToBeMocked;

-(void)somePrivateMethod;

@end

answered Aug 10 '12 at 16:59

Christopher Pickslay

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Thank you! This is beautiful. I totally forgot about that aspect of Objective-C ;-) – Shiun Aug 23 '12 at 20:48
1

@abellina no you can't currently mock class methods with OCMock – Christopher Pickslay Sep 27 '12 at 00:07

score 1 · Answer 2 · answered Aug 10 '12 at 11:04

1

Does the following work?

id classUnderTest = ... // get from somewhere
id mock = [OCMockObject mockForClass:[ClassToBeMocked class]];
[classUnderTest setValue:mock forKey:@"nameOfThatPrivateProperty"];

Not totally sure whether you can set private properties like this. I think it depends on what kind of property it is.

answered Aug 10 '12 at 11:04

Erik Doernenburg

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Can you get properties like this as well? – fatuhoku Apr 03 '14 at 09:59
Yes - this is just using KVC within the Foundation framework. See here: https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/KeyValueCoding/Articles/KeyValueCoding.html#//apple_ref/doc/uid/10000107-SW1 – Sean Michael Dorian Aug 17 '15 at 20:42

How do you mock out private properties with OCMock for iOS?

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