Unrecognized Selector SenTestCase for Category

Question

I created a new Cocoa Touch Static Library project with Unit Testing in XCode 4 and added a category:

// NSString+Inflections.h
@interface NSString (Inflections)
- (NSString *)pluralize;
@end

// NSString+Inflections.m
@implementation NSString (Inflections)
- (NSString *)pluralize { return self; }
@end

then added the appropriate import statement to my test cases and wrote the following test:

- (void)testPluralize
{
  NSString *test = @"person";
  NSString *expected = @"people";

  NSString *actual = [test pluralize];

  STAssertEqualObjects(actual, expected, @"Whoops"); 
}

However, this causes my tests to crash (not fail) with 'unrecognized selector sent to instance'.

How can I test a category inside a library?

I've compressed and uploaded the full project here if my description is inadequate.

score 19 · Accepted Answer · answered Mar 27 '13 at 23:05

19

I was searching for an answer this problem myself and found (I believe) a simpler solution, which doesn't require remembering to add a reference in the Compile Sources list whenever a new category class is added to the project.

In the test target's build settings, add -ObjC to the Linking / Other Linker Flags value.

Further explanation for why this error actually happens can be found at Apple Reference.

answered Mar 27 '13 at 23:05

Bill

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This should be the accepted answer. Sometimes I wish I could upvote more than once. – Shaggy Frog Apr 04 '13 at 02:52
@Shaggy Sorry I didn't change out the answer. I just ran into this problem again and this is a much better fix. – Kevin Sylvestre Aug 26 '13 at 02:51
not work for me :( I have static library need to write unit test. Code compile and build successfully but test case fail unrecognized selector. It works fine when I add .m file in test target – Amit Battan Sep 04 '17 at 09:35
When I am adding -ObjC lot of `Apple Mach -O` error comes – Amit Battan Sep 04 '17 at 14:13

score 13 · Answer 2 · edited May 23 '17 at 12:26

13

Edit: Be sure to see this answer about unit test not finding files

+1 For uploading the project. The problem is your test target does not include NSString+Inflections.m in the Build Phases.

In XCode 4

Click "Poppy" in the top of the Navigator
Select "PoppyTests" under Targets
Go to Build Phases
Expand Compile Sources
Click the + sign and then add NSString+Inflections.m

You should then get something similar the following output

TestSuite '/blahblah/PoppyTests.octest(Tests)' finished at 2011-03-28 21:31:34 +0000. Executed 1 test, with 1 failure (0 unexpected) in 0.000 (0.002) seconds

edited May 23 '17 at 12:26

Community

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answered Mar 28 '11 at 21:35

Joe

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Thanks. That fixed the problem, but PoppyTest target does have Poppy as a dependency. I did a bit more looking and found that it can also be fixed by adding `-all_load` as a Other Linker Flag for the PoppyTest target (under Build Settings). This way one wouldn't need to add all source files to both targets. – Kevin Sylvestre Mar 28 '11 at 21:44
1

That is correct I did not see that, I was thinking it was an `-all_load` kind of issue at first because you were working with a category. I would recommend `-force_load [dependency name]` if it were not a unit test because that option will only load all symbols in the specified dependency. – Joe Mar 29 '11 at 13:25
This fixed it for me. The odd part was it was working fine and when it stopped working for me it was using the old source files. – robhasacamera Jul 05 '12 at 21:19
1

@KevinSylvestre How do you set the -all_load flag? Is it somewhere in Build Settings? – robhasacamera Jul 05 '12 at 21:34
2

Bill's answer below is much better than this one. You should not manually add your library's source files to the unit test target. Every time you do, a kitten cries. You should link your unit test against your library instead. Every time you do that, a kitten smiles. – Shaggy Frog Apr 04 '13 at 02:54

Daniel Saidi · Answer 3 · 2013-03-25T22:40:25.170

I can also confirm that adding the required files to the Test project's Build Phases > Compile Sources collection solves this problem. Thanks a bunch!

When I tried the -all_load approach, however, I started to receive a bunch of errors, like that _CGSizeZero is undefined for architecture i386. It turns out that some code - like this one, where I use CGSizeZero in one of my classes - can make the second approach break.

Once I replaced CGSizeZero with CGSizeMake(0, 0), however, the second approach worked great as well.

score 1 · Answer 4 · answered Nov 02 '16 at 04:34

1

I had the same situation when i was working in the Objective-c project. I did the following steps and it went well.

1) Select the project and goto target.

2) select Test target and add -ObjC like showing in the image.

3) Now try to run the unit XCTest.

answered Nov 02 '16 at 04:34

Zumry Mohamed

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Unrecognized Selector SenTestCase for Category

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