Xcode: declare method in public header only in DEBUG mode - objective-c

I am developing a framework that connects to a hard coded url. I'd like to be able to change that url in automated tests. I adding the following to my umbrella header:
#ifdef DEBUG
- (void)setServerUrl;
#endif
I thought that if I build the framework in -configuration Release mode, the preprocessor would delete the method declaration from the code, which is what I want.
So, maybe my approach was wrong to begin with, or it was right but the implementation wasn't. In any case, how do I expose a method in DEBUG mode only? Is it possible?

Don't put this method in public header.
In yours automated test add category, that makes this method visible for them.

Related

Best way to create global god mode variables in Objective-C

I want to have some "god mode" boolean toggles to quickly change functionality inside my app.
The previous developer created #define macros for these in a file that's included (indirectly) in every other file, but there are some disadvantages:
Every change has to be commited in git
Every change forces a build of the entire project
Is an xconfig file suited for this case? I accomplished what I want by:
Creating an .xconfig file
Adding it to the project
Adding HACKS_TEST = YES to it
Adding preprocessor macro HACKS_TEST=${HACKS_TEST} to the project target
Adding static BOOL const IOHacksTest = HACKS_TEST
and upon logging it, the value is printed correctly. But, if I change the HACK_TEST's value in the .xconfig file, it still builds the entire project. Also, adding one 'hack', needs modifications in the .xconfig file, project target's preprocessor macro section and project's global file.
Is it possible to achieve this without the need of an entire project build?
Is there another solution that doesn't require these many modifications on new 'hacks' adding?
Is there another solution that is more appropriated to my needs and/or easier/better?
What is the best way to have them set to NO for the Release configuration?
Edit:
Along the selected solution, I also added this in the Globals.m file:
if #debug
BOOL IOHacksTest = YES;
#else
BOOL IOHacksTest = NO;
#endif
so for Release builds, all the "hacks" are turned off automatically.
Every change has to be commited in git
You can't, or really shouldn't try to, avoid this. If there's some setting that can affect how the whole project works, it should be archived with the project.
As you've discovered, putting the values in an .xcconfig file doesn't have much advantage over having #defines for everything - if you change the xcconfig file, yo have to rebuild everything.
To avoid that, you'll want to split the declaration and definition of the variables between a header and a source file. So, you'd have a goobals.h file that contains "extern" declarations, like this:
extern BOOL IOHacksTest;
And a goobals.m file that has:
BOOL IOHacksTest = YES;
Then you include goobals.h wherever you need the declarations. If you need to change a value, you only need to recompile a single file.
1, Is it possible to achieve this without the need of an entire
project build?
If you want code to be compiled differently, based on those changing values, then there is no way to do it. In fact, you want the project to be recompiled, because the generated code needs to change.
The best way to prevent an entire project build is to put those values into a header file, and selectively include that header file only in files that need to know about the values that could change.
Is there another solution that doesn't require these many modifications on new 'hacks' adding?
There is no way getting around it if you want compile-time detection. If you change the values, then the compiler has to generate new code. How could the compiler generate the right code if it does not know about the custom changes you want to make with your "changes?"
Is there another solution that is more appropriated to my needs and/or easier/better?
That depends on your actual needs, which you didn't state in the original question. If you must have compile-time knowledge of the changes, you can use the header files, or you can add values to .xcconfig files, or just set them in the project. However, you will still have to recompile all the code that is impacted every time the values change.
If you want the settings to be changed at run time, then this is precisely what NSUserDefaults is designed for. Set an initial value in the source code, or in the Info.plist file, and set it to user-defaults on the app's first launch. Thereafter, you can manage the values from user-defaults.
What is the best way to have them set to NO for the Release configuration?
static BOOL builtInDebugMode = !!(DEBUG);
EDIT
Also, what does !!(DEBUG) do? – Iulian Onofrei
That's a logical-not operator, employed twice. It ensures that its operand will always be either 1 or 0. It was there to guide you to how it could be done (i.e., consider DEBUG or NDEBUG at compile time).
By default, your xcode configuration will have DEBUG=1 for debug builds. You could set it to DEBUG=0 for release builds, and use the above code.
As long as your code properly handles DEBUG, this should be fine. Unfortunately, some code incorrectly uses #ifdef DEBUG rather than #if DEBUG which could cause issues.
Thus, you may be better off with something like...
#if DEBUG
static BOOL builtInDebugMode = YES;
#else
static BOOL builtInDebugMode = NO;
#endif
When compiled in debug mode, DEBUG will be defined as 1. When not in debug mode, it will not be defined at all.
Or, you could add a definition to your project file DEBUG_VALUE
You can set some value in NSUserDefault, is very easy to use, I think.
You can add buttons to your app's UI to toggle these values, or you can let app query some website for this value at first launch, depends your needs.
NSUserDefault is fast.
And you can query at launch, and use it util app quit.

How to create Apple mail plugin

I'm going to create a mail plugin for the OS X Mail.app application for some additional features.
I have no idea where to start as there is no official documentation for plugins.
Can anyone please help me, how can I start the project.
Is there any initial link or tutorial, please suggest?
As noted, writing Apple Mail plugins is not straightforward, since it only has a private plugin API, which is entirely undocumented and can change with any new version of Mail.app. The best code example is GPGMail, which is open source & still active (already working on Yosemite support). Here is what I successfully did to get started (will put it up on github once finished):
How to build a minimal Apple Mail plugin (as of Mavericks & Xcode 6.0.1)
you need to create an OSX "Bundle" project in XCode
wrapper extension is mailbundle (under Packaging in the project Build settings)
a bundle needs to be stored under ~/Library/Mail/Bundles (as Build Phase add a Copy Files action with that as absolute path destination and the *.mailbundle from your build/ folder as item to copy)
for development, I have set up /Applications/Mail.app as executable in my run scheme, so that Run in XCode will build it, copy the bundle and start mail; note that at this point you'll get an error from Mail that your plugin cannot be started and was disabled
you need to provide a list of SupportedPluginCompatibilityUUIDs in the Info.plist, I stole it from GPGMail, these change with new Mail/OSX versions
use class-dump to generate the header files from Mail.app's private API
starting point is MVMailBundle, which you have to inherit from and which has a registerBundle method to hook you in
I extracted that from the huge generated header file in a small MVMailBundle.h header to include where needed (as done by GPGMail)
create a new class MyMailBundle, inheriting from NSObject
it needs an initialize method
and set it as "Principle class" in the Info.plist so that it gets run when the bundle is loaded by Mail.app
#import <Cocoa/Cocoa.h>
#interface MyMailBundle : NSObject
+ (void)initialize;
#end
initialize implementation: previously, you could use the simple way and directly inherit as done in Letterbox, however, since 64-bit runtimes of Objective-C you have to use the dynamic way as done by GPGMail:
using NSClassFromString to dynamically get the MVMailBundle class
and class_setSuperclass from <objc/runtime.h> to have your own class inherit from it
and then call registerBundle on it casted as MVMailBundle (requires include of MVMailBundle.h)
#import <objc/runtime.h>
#import "MVMailBundle.h"
#import "MyMailBundle.h"
#implementation MyMailBundle
+ (void)initialize
{
NSLog(#"Loading MyMail plugin...");
// since 64-bit objective-c runtimes, you apparently can't load
// symbols directly (i.e. through class inheritance) and have to
// resort to NSClassFromString
Class mvMailBundleClass = NSClassFromString(#"MVMailBundle");
// If this class is not available that means Mail.app
// doesn't allow plugins anymore or has changed the API
if (!mvMailBundleClass)
return;
// dynamically change super class hierarchy
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated"
class_setSuperclass([self class], mvMailBundleClass);
#pragma GCC diagnostic pop
// register our plugin bundle in mail
[[((MyMailBundle *)self) class] registerBundle];
NSLog(#"Done registering MyMail plugin.");
}
#end
add some NSLog logging calls to verify the right thing is happening, they'll be visible in XCode's console when running/debugging Mail.app from within XCode or alternatively in the system logs of Console.app
This should successfully run the plugin in Mail with no error!
The next steps involve crazy things like MethodSwizzling and ClassPosing to modify Mail's behavior, where GPGMail can be a helpful example. (Haven't been there myself yet)
For reference, here are some of the resources that helped me:
GPGMail
Adam Nash: Getting Ready to Write an Apple Mail.app Plug-in for Mac OS X - some good links, but apparently he never finished the project, so no code
James R. Eagan: Demystifying Mail.app Plugins on Leopard - using PyObjC to write a plugin in Python, explains the basic mechansims, very useful
Aaron Harnly: Mail Plugin Template - for XCode 2 I think, unfortunately the template (download a zip) doesn't work as template in Xcode anymore, but the code is still useful to look at
Aaron Harnly: Letterbox sources - from the same guy, but also from 2007, very outdated; contains a readme from the template, though it doesn't really help if you can't use the template.
There is no official supported way to build such a tool - you need to start trying to hook in to Mail.app without any official support.
If you want to persist on this sort of thing, then you'll need to understand how Mail.app internals work, which is a bunch of using the debugger and class dump to inspect libraries in other apps:
https://github.com/nygard/class-dump
You'll probably also want a way to inject code into other applications, for example:
https://github.com/rentzsch/mach_inject
And every time Apple update Mail.app you'll potentially need to redo everything :)

Xcode - conditional development or production mode

In searching for this I could only find info for other languages. I would like to know the best practice for writing conditional statments such as:
if (DEV_MODE){
//do something
}else{
//do the real stuff
}
And then setting DEV_MODE on or off in some global file so I only have to change that to on or off instead of changing code in multiple places. I have some ideas but am looking for advice on the best way to do this.
Try this:
#ifdef DEBUG
// do stuff
#endif
The current version of Xcode automatically sets this macro in new projects. Go to your projects Build Settings to make sure. If it's not there you have to add it yourself:
(This question is not related to Xcode.)
That said, instead of polluting your code with C-style IFs, you can use preprocessor directives to filter out debug and release mode. As far as I know, it's a common practice to define the DEBUG macro to 1 if in testing mode, and not to define it if in release mode. (Also, Xcode may define this for you, I've seen this behavior having been relied upon.) The reason is that the use of the preprocessor is more readable, since it doesn't get into the indentation, it's better separated from the code visually. To sum up, try
#ifdef DEBUG
// do debug stuff here
#else
// do release stuff here
#endif
One extra argument for preprocessor macros is that you can conditionalize the global namespace, which you couldn't within C code. I. e., with preprocessor macros, you can write
#ifdef DEBUG
int functionOne()
{
}
#else
char *functionTwo(int a)
{
}
#endif
You couldn't do this without the preprocessor.
Preprocessor variables are what you want, in your build configurations define a variable (DEV_MODE for example), and then use preprocessor checks like:
#if DEV_MODE
//dev mode code
#else
//non-dev mode code
#endif
In your project settings there is a section called "Preprocessor Macros". In that section you can add a string for your Debug build such as "DEV_MODE" or whatever you want. Then you can do your conditions you listed above and when your app gets built for "Release" or any other setting that does not contain your macro your check should fail.

Objective-c obfuscation of methods works in DEBUG but crashes in RELEASE

I made a xcode project where i did some security stuff and they asked me to obfuscate the method names
like so
#define specialMethod a9328238
+(void) specialMethod
{
// do security stuff
}
i made a .framework library from the project ( project A ) and included it into another project ( project B ).
but when i run (project B) with a Release build configuration it always crashes like so.
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[SecurityClass a9328238]: unrecognized selector sent to class 0x337cc4'
so it crashes when it tries to acces the method.
But when i run (project B) it with a Debug build configuration it runs smooth
(i have kept all my build configuration settings as default)
Where have you placed the #define for obfuscation ? Is it in the header file (.h) or in the implementation file (.m) of the framework ?
For the obfuscation to be effective, it must be placed in a file that is both included by the implementation and the caller.
You can also check that the pre-processing is ok by inspecting the pre-processed file. Select the implementation file and go to the menu Product > Generate Output > Generate Preprocessed File (you can select the configuration at the bottom of the screen).
My hunch is the #define location/visibility as well.
But you may want to consider this from another angle. You could change:
#define specialMethod a9328238
+(void) specialMethod
{
// do security stuff
}
to:
#interface SecurityClass : NSObject
// private obfuscated interface:
+ (void)a9328238;
// {
// do security stuff in a9328238's definition
// }
#end
// here is the public interface:
static inline void SecurityClass_LogIn() {
[SecurityClass a9328238];
}
dropping #define altogether.
In use:
SecurityClass_LogIn();
…
Since this is a class method, you could write an obfuscated function wrapped in a human readable inline instead. A well crafted C implementation will be much more difficult to pick apart than objc.
A more complete example would help us narrow down the possibilities.
Also verify there are no warnings -- the compiler may warn you if you have called an undeclared selector. It's possible that the method is called where the #define is not visible in other cases.
It seems that the executable which imports the obfuscated framework tries to access the non-obfuscated methods.
You should check the symbols in the framework. Use nm on the static library in the framework to see the exported symbols (marked with a 't'). Make sure the symbols are obfuscated.
If you've wrapped everything into a framework, have you made sure that the appropriate headers are exposed outside of the framework? Headers inside a framework aren't exposed the same way as normal files are. Go to your Project->Build Phases, in the bottom right you should see "Add Copy Headers". This will add a new section in your build phases. Inside this section, click the "+" and the headers that define your method names.

Run logic tests in Xcode 4 without launching the simulator

I want to run tests in Xcode 4 using OCUnit without launching the simulator. Please, don't try and convince me I am doing unit testing wrong or anything like that. I like to do TDD the traditional way: write the API for the class in the tests, then make the class pass the tests. I will write separate tests that are end-to-end that run in the simulator.
If there's no way to do this, then please can someone tell me how to have the test harness not instantiate the whole app? My app is event driven, and it sends a bunch of events through when it starts up that mess with my tests.
Please can someone tell me how to have the test harness not instantiate the whole app? My app is event driven, and it sends a bunch of events through when it starts up that mess with my tests.
I use Xcode 4's built-in testing. App instantiation may seem like a pain, but as I write on Xcode Unit Testing: The Good, the Bad, the Ugly, it makes it possible to write tests without distinguishing between logic tests and application tests. Specifically, it lets me write unit tests for view controllers.
Here's what I do to avoid my full startup sequence:
Edit the scheme
Select the Test action
In "Test" select the Arguments tab
Disable "Use the Run action's options"
Add an environment variable, setting runningTests to YES
Edit your app delegate
Add the following to -application:didFinishLaunchingWithOptions: as soon as it makes sense to:
#if DEBUG
if (getenv("runningTests"))
return YES;
#endif
Do the same for -applicationDidBecomeActive: but simply return.
Update: I have changed my approach. See How to Easily Switch Your App Delegate for Testing.
In the last xcode version (5.0.2) you can do this in very easy way. Choose your Test target, "General" tab. Set "None" in field "Target". Then tap on "Build phases" tab and remove your Main target from "Target dependencies".
In your situation, I am assuming that you have a separate Logic Tests and Application Tests target (if not - you need to). In your schemes configuration you define which targets are built for the 'Test' scheme. If your application tests are not running, the simulator will not launch.
I suspect that you might be trying to run 'logic tests' in an 'Application tests' target (such as the one created by default by Xcode). See more about this difference here (and how to set ut up).
It was pointed out in an earlier answer that logic tests are the right thing to do for this scenario. I had very tough time in getting the logic tests working with XCode Version 4.3.2 (4E2002). Looking at Apple's sample unit test project helped me to understand how to do this with a clear separation. In that example, logic tests test files from the library target, not the application target. The model was encapsulated into a library which was then linked with the main target and logic tests target. The application target contained only views and controllers.
Based on this model, this is what I did to get my logic tests work correctly. Create a new target (Cocoa Touch Static Library) and move all files to be logic tested (typically all your models) to this new target. Under "Build Phases" settings add this new library in "Link Binary With Libraries" of your application target and logic tests target.
I can imagine that these instructions are little confusing. If you dissect the sample project that is mentioned above you will get a better idea.
Note, untested on Xcode 5.
I used #jon-reid’s answer, but found that Xcode adds environment-variables to the xcuserstated part of XcodeProjects, and these are user specific and not typically committed to the repository. Thus I swizzle my AppDelegate to override its loading:
#implementation MyAppDelegate (Testing)
+ (void)initialize {
SEL new = #selector(application:didFinishLaunchingWithOptions:);
SEL orig = #selector(swizzled_application:didFinishLaunchingWithOptions:);
Class c = [self class];
Method origMethod = class_getInstanceMethod(c, orig);
Method newMethod = class_getInstanceMethod(c, new);
if (class_addMethod(c, orig, method_getImplementation(newMethod), method_getTypeEncoding(newMethod))) {
class_replaceMethod(c, new, method_getImplementation(origMethod), method_getTypeEncoding(origMethod));
} else {
method_exchangeImplementations(origMethod, newMethod);
}
}
- (BOOL)swizzled_application:(id)app didFinishLaunchingWithOptions:(id)opts {
return YES;
}
#end
Note, that the following is simpler and still works, though I'm not sure it is reliable:
#implementation MyAppDelegate (Testing)
- (BOOL)application:(id)app didFinishLaunchingWithOptions:(id)opts {
return YES;
}
#end
This works because categories of methods in dynamically loaded components (like the testing bundle) take precedence. Swizzling feels safer though.
Using xCode 7 and xctool
xctool is capable of executing unit tests without the simulator.
To get this working,
1 . Update the target settings run without a host app.
Select your project --> then test target --> Set the host application to none.
2. Install xctool , if you don't have it.
brew install xctool
3. Run the tests using terminal with xctool.
xctool -workspace yourWorkspace.xcworkspace -scheme yourScheme run-tests -sdk iphonesimulator
i've used GHUnit to create osx/ios compatible test suites. there are a few issues, but i found it was more reliable/compatible/straightforward than OCUnit.
GHUnit provides basic template projects for OS X and iOS, which makes initial setup simple.
Note: I generally just use my own kit for most of my testing.