Objective-c – How do i mock a method that accepts a handle as an argument in OCMock

handlemockingobjective cocmockunit testing

I'm trying to mock a method that has the equivalent of the following signature:

- (NSDictionary *) uploadValues:(BOOL)doSomething error:(NSError **)error

I want it to return a small dictionary so that my test can make sure the code uses the dictionary properly. however, no matter what i do OCMock always returns nil from the method, regardless of how i stub it out. The error begins as nil in the code i'm testing, and these are the different ways i've tried stubbing it:

NSError * error = nil;
[[[mock stub] andReturn:someDict] uploadValues:YES error:&error];

[[[mock stub] andReturn:someDict] uploadValues:YES error:nil];

[[[mock stub] andReturn:someDict] uploadValues:YES error:[OCMArg any]];

and none of them work. Does OCMock support handles as stubbed message arguments and if so, what's the correct way to do it?

Best Answer

[[[mock stub] andReturn:someDict] uploadValues:YES error:[OCMArg setTo:nil]];

NSError* someError = ...
[[[mock stub] andReturn:someDict] uploadValues:YES error:[OCMArg setTo:someError]];

You could also do

[[[mock stub] andReturn:someDict] uploadValues:YES error:[OCMArg anyPointer]];

but this might cause your code to incorrectly think that you passed back a real NSError.

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Java – How to test a class that has private methods, fields or inner classes

Update:

Some 10 years later perhaps the best way to test a private method, or any inaccessible member, is via @Jailbreak from the Manifold framework.
@Jailbreak Foo foo = new Foo();
// Direct, *type-safe* access to *all* foo's members
foo.privateMethod(x, y, z);
foo.privateField = value;
This way your code remains type-safe and readable. No design compromises, no overexposing methods and fields for the sake of tests.

If you have somewhat of a legacy Java application, and you're not allowed to change the visibility of your methods, the best way to test private methods is to use reflection.

Internally we're using helpers to get/set private and private static variables as well as invoke private and private static methods. The following patterns will let you do pretty much anything related to the private methods and fields. Of course, you can't change private static final variables through reflection.

Method method = TargetClass.getDeclaredMethod(methodName, argClasses);
method.setAccessible(true);
return method.invoke(targetObject, argObjects);

And for fields:

Field field = TargetClass.getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);

Notes:
1. TargetClass.getDeclaredMethod(methodName, argClasses) lets you look into private methods. The same thing applies for getDeclaredField.
2. The setAccessible(true) is required to play around with privates.

Iphone – How to i get OCMock to let me stub a category method on a UIKit class

I figured out the problem; the file that had the class category defined in it wasn't in the correct target in my project. It was in the main target but not the unit test target. adding it to the right place made it work swimmingly.

Best Answer

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Java – How to test a class that has private methods, fields or inner classes

Iphone – How to i get OCMock to let me stub a category method on a UIKit class

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