Question

I’m attempting to follow along with the RestKit unit test guide ( https://github.com/RestKit/RestKit/wiki/Unit-Testing-with-RestKit ) except that my project is a static library instead of an app.

Here is the test I’ve written:

- (void)testMappingOfDate
{
    id parsedJSON = [RKTestFixture parsedObjectWithContentsOfFixture:@"plan.json"];
    RKMappingTest *test = [RKMappingTest testForMapping:[self planMapping] object:parsedJSON];
    [test expectMappingFromKeyPath:@"plan.date" toKeyPath:@"date"];
    STAssertNoThrow([test verify], nil);
}

When I attempt to run the test I receive this error on the first line of the test:

error: testMappingOfDate (api_clientTests) failed: -[NSBundle parsedObjectWithContentsOfResource:withExtension:]: unrecognized selector sent to instance 0x1765c40

It seems like its not finding the NSBundle category defined by RestKit, but my test target header search path is set to "$(BUILT_PRODUCTS_DIR)/../../Headers" and I’ve verified this path includes NSBundle+RKAdditions.h which contains the supposed “unrecognized selector”.

Is there something I’m missing here?

Answer 1

You are trying to include a category within your binary that comes from a library. To get that accomplished you will need to add the following to your (Unit-Test-Target’s) build settings.

Other Linker Flags: -ObjC

From Apple’s QA:

Objective-C does not define linker symbols for each function (or
method, in Objective-C) – instead, linker symbols are only generated
for each class. If you extend a pre-existing class with categories,
the linker does not know to associate the object code of the core
class implementation and the category implementation. This prevents
objects created in the resulting application from responding to a
selector that is defined in the category.

Solution:

To resolve this issue, the static library should pass the -ObjC option
to the linker. This flag causes the linker to load every object file
in the library that defines an Objective-C class or category. While
this option will typically result in a larger executable (due to
additional object code loaded into the application), it will allow the
successful creation of effective Objective-C static libraries that
contain categories on existing classes.