Communication error while building the unit test target

Question

I have an XCode4 / iOS project with the usual goal and unit test. Everything works fine, except when I try #import one of my classes in my test class and try to use it. If I try to create a unit test target, I get the following link error:

Undefined symbols for architecture i386: "_OBJC_CLASS_$_FRRCategory", referenced from: objc-class-ref in CategoryTests.o ld: symbol(s) not found for architecture i386 collect2: ld returned 1 exit status 

In CategoryTests.m, I import the header file as follows:

 #import "../todoro/FRRCategory.h" 

What am I doing wrong?

Answer 1

Make sure the FRRCategory source file is added to your compilation sources for your unit test purpose.

Xcode 4:

Project Navigator → "[Project Name]" → In the "Targets" section, select the unit test target → Assembly phases → Deploy compilation sources → Click + at the bottom of the compilation sources and add the correct source file.

Answer 2

Follow the instructions here . This does not require you to add files to compile sources.

I first skipped that “Characters hidden by default = NO” should be for your application purpose, not for checking purpose.

It worked for me anyway (tm).

Answer 3

Another problem you can cause is if your unit test uses C functions (or similar) that are not used in a real application.

This may be limited by the presence of a subproject. In my case

• The app
  • subproject
    • C built-in library (i.e. c and .h files compiled directly inside)

My unit test used several C functions that were not used anywhere, and they were removed from the application binary (NOT from the sub project.a file).

The fix is

• disable Dead Code Removal for the Debug build application. * and
• make sure your unit tests use Debug, not Release, in your schema settings.

(* Do not do this with release configurations, as it will inflate the application with code that is never called).

Answer 4

You should only reference the folder inside your import if your file is inside the frame. Otherwise, once you have added your file to the project, just do #import "FRRCategory.h" . Well, if you haven’t done something strange using the header search paths.