I have a method from a class under tests which takes two delegates: the second delegate will call a method after the first delegate will be called with a callback function as input.
#implemenation ClassUnderTest
...
- (void) methodWithMultipleCallbacks: (id<MyDelegate>) delegate
withSecondDelegate: (id<MyDelegateWithCallback>) delegateWithCallback {
for (int i = 0; i < 2; i++){
Callback callback = ^(int input) {
NSLog(#"%d-th callback", i);
NSLog(#"input = %d", input);
};
[delegateWithCallback fetchInt:callback];
}
[delegate delegateDoStuff:32];
}
But the strange thing happens: I tried to test it using OCMock, mocking both delegates, but the crashes, and I got a EXEC_BAD_ACCESS.
I am utterly confused and would really appreciate any help here! Here's the test function
- (void) testWithMultipleCallbacks {
id <MyDelegateWithCallback> mockDelegateWithCallback = OCMProtocolMock(#protocol(MyDelegateWithCallback));
OCMStub([mockDelegateWithCallback fetchInt:[OCMArg any]]).andDo(^(NSInvocation *invocation) {
void (^block)(int) = NULL;
[invocation getArgument:&block atIndex:2];
NSLog(#"got here");
block(33);
});
[_classUnderTest methodWithMultipleCallbacks: _mockedDelegate withSecondDelegate: mockDelegateWithCallback];
OCMVerify(OCMTimes(1), [_mockedDelegate delegateDoStuff:[OCMArg any]]);
}
Related
I have a project with a lot of classes.
I want to log (e.g. to stderr) invocations of each selector in runtime.
My main requirement is not to change the existing code, so I can't just log the function's params at the start of each call.
If some method is invoked during program execution, e.g.
#implementation Class1
// ...
- (int)someFunc:(Class2*) a andClass3:(Class3*)b
{
}
// ...
#end
I want to replace it with something like:
- (int)someFuncWrapper:(Class2*) a andClass3:(Class3*)b
{
NSLog(#"- (int)someFuncWrapper:a andClass3:b <= a=%#, ab=%#", a, b);
return [someFunc: a andClass3:b];
}
Is it possible?
I've read of method swizzling, KVO, forward messaging.
My current approach with method swizzling causes infinite recursion:
- (int)funcToSwizzle:(int)a andB:(int)b
{
int r = a+b;
NSLog(#"funcToSwizzle: %d", r);
return r;
}
- (void)doSimpleSwizzling
{
NSLog(#"r1 = %d", [self funcToSwizzle:10 andB:20]);
Class curClass = NSClassFromString(#"HPTracer");
unsigned int methodCount = 0;
Method *methods = class_copyMethodList( curClass, &methodCount);
for (int i=0; i<methodCount; ++i)
{
SEL originalSelector = method_getName(methods[i]);
if ( strcmp("funcToSwizzle:andB:", sel_getName(originalSelector)) == 0 )
{
Method m1 = class_getInstanceMethod(curClass, originalSelector);
id block3 = ^(id self, int a, int b) {
NSLog(#"My block: %d", a*b);
// get current implementation of "funcToSwizzle".
// copy it. store that "IMP"/"void *" etc
return [self funcToSwizzle:a andB:b];
};
IMP imp3 = imp_implementationWithBlock(block3);
method_setImplementation(m1, imp3);
}
}
NSLog(#"r2 = %d", [self funcToSwizzle:10 andB:20]);
}
And I'm afraid it's impossible to generate a block3 or some method in runtime. There's NSSelectorFromString but no ImplementationFromString.
UPD
I looked at DTrace util, it seems very powerful, but doesn't fit my needs.
It requires disabling SIP on Mac OS, and is either impossible on iOS or possible on jailbreaked device.
What I need from methods interceptions is creating a stable custom "framework" for both Debug and production build modes.
for example:
-(void) myExample {
..do something
}
void myOther(){
how to call myExample function here
}
When you call myOther, pass self reference. you should define the C method like this:
void myOther(id callBack)
Now you have self reference in c function.
void myOther(id callBack){
[callBack myExample];
}
If both methods are in same Class than you can directly call First method from Second methods as follows:
-(void) myExample {
..do something
}
void myOther(){
call to myExample function
[self myExample];
}
read docs here: https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/WorkingwithObjects/WorkingwithObjects.html
void getInputSource() {
TISInputSourceRef source = TISCopyCurrentKeyboardLayoutInputSource();
NSLog(#"languages: %#", TISGetInputSourceProperty(source, kTISPropertyBundleID));
NSLog(#"localized name: %#", TISGetInputSourceProperty(source, kTISPropertyLocalizedName));
[self awakeFromNib];
}
-(void) awakeFromNib {
self.statusBar = [[NSStatusBar systemStatusBar] statusItemWithLength:NSSquareStatusItemLength];
NSImage* icon = [NSImage imageNamed:#"icon.png"];
self.statusBar.image = icon;
}
I'm having a hard time finding good examples on how to use these functions.
static void * kQueue1Key = "key1";
static void * kQueue2Key = "key2";
dispatch_queue_t queue1 = dispatch_queue_create("com.company.queue1", DISPATCH_QUEUE_SERIAL);
dispatch_queue_t queue2 = dispatch_queue_create("com.company.queue2", DISPATCH_QUEUE_SERIAL);
dispatch_queue_set_specific(queue1, kQueue1Key, (void *)kQueue1Key, NULL);
dispatch_queue_set_specific(queue2, kQueue2Key, (void *)kQueue2Key, NULL);
dispatch_sync(queue1, ^{
if(dispatch_get_specific(kQueue1Key))
{
NSLog(#"I'm expecting this line to run (A)");
dispatch_sync(queue2, ^{
NSLog(#"I'm expecting this line to run (B)");
if(dispatch_get_specific(kQueue2Key))
{
if(dispatch_get_specific(kQueue1Key))
{
NSLog(#"I'm expecting this line to run (C)");
}
else
{
[NSException raise:NSInternalInconsistencyException format:#"Should not end up here (C)"];
}
}
else
{
[NSException raise:NSInternalInconsistencyException format:#"Should not end up here (B)"];
}
});
}
else
{
[NSException raise:NSInternalInconsistencyException format:#"Should not end up here (A)"];
}
});
Result
I'm expecting this line to run (A)
I'm expecting this line to run (B)
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Should not end up here (C)'
Is it expected behavior? If I were to dispatch_sync to queue1 since I'm not on the queue I would deadlock. What am I missing?
Oh here, it popped into my head why you're getting what you're getting. Notes in line:
dispatch_sync(queue1, ^{
When you get to this point, the "current queue" is queue1
if(dispatch_get_specific(kQueue1Key))
You're asking the current queue for the value it has for kQueue1Key, you set that earlier, so it gives it back to you.
{
NSLog(#"I'm expecting this line to run (A)");
dispatch_sync(queue2, ^{
When you get to this point, the "current queue" is now queue2
NSLog(#"I'm expecting this line to run (B)");
if(dispatch_get_specific(kQueue2Key))
You're asking the current queue for the value it has for kQueue2Key, you set that earlier, so it gives it back to you.
{
if(dispatch_get_specific(kQueue1Key))
You're now asking the current queue for the value it has for kQueue1Key. Since the current queue is queue2 and you never set a value with kQueue1Key on queue2 you get back NULL.
{
NSLog(#"I'm expecting this line to run (C)");
}
else
{
[NSException raise:NSInternalInconsistencyException format:#"Should not end up here (C)"];
}
The misunderstanding here is that dispatch_get_specific doesn't traverse the stack of nested queues, it traverses the queue targeting lineage. For instance, if you did this instead,
static void * kQueue1Key = (void*)"key1";
static void * kQueue2Key = (void*)"key2";
dispatch_queue_t queue1 = dispatch_queue_create("com.company.queue1", DISPATCH_QUEUE_SERIAL);
dispatch_queue_t queue2 = dispatch_queue_create("com.company.queue2", DISPATCH_QUEUE_SERIAL);
dispatch_queue_set_specific(queue1, kQueue1Key, (void *)kQueue1Key, NULL);
dispatch_queue_set_specific(queue2, kQueue2Key, (void *)kQueue2Key, NULL);
// Set Queue2 to target Queue1
dispatch_set_target_queue(queue2, queue1);
dispatch_sync(queue2, ^{
if(dispatch_get_specific(kQueue1Key))
{
NSLog(#"I'm expecting this line to run (A)");
}
else
{
[NSException raise:NSInternalInconsistencyException format:#"Should not end up here (C)"];
}
if(dispatch_get_specific(kQueue2Key))
{
NSLog(#"I'm expecting this line to run (B)");
}
else
{
[NSException raise:NSInternalInconsistencyException format:#"Should not end up here (C)"];
}
});
...the targeting relationship is the one that gets traversed, not the stack relationship. It would be nice if there were something that traversed the stack relationship, but I'm not aware of anything (that you wouldn't have to implement yourself).
As mentioned in my comment, recursive locking using dispatch_sync is, in the general case, not possible due to the possibility of non-default queue targeting. For what it's worth, given/assuming default queue targeting, here is one possible approach:
#import <unordered_set>
#import <pthread.h>
static dispatch_once_t recursiveLockWithDispatchQueueTLSKeyOnceToken;
static pthread_key_t recursiveLockWithDispatchQueueTLSKey;
typedef std::unordered_multiset<const void*> RecursiveLockQueueBag;
static void freeRecursiveLockWithDispatchQueueTLSValue(void* tlsValue)
{
RecursiveLockQueueBag* ms = reinterpret_cast<RecursiveLockQueueBag*>(tlsValue);
if (ms) delete ms;
}
static inline BOOL queueStackCheck(dispatch_queue_t q, BOOL checkAndPushNotPop) // If yes, check and push if not on. If no, pop.
{
dispatch_once(&recursiveLockWithDispatchQueueTLSKeyOnceToken, ^{
pthread_key_create(&recursiveLockWithDispatchQueueTLSKey, freeRecursiveLockWithDispatchQueueTLSValue);
});
RecursiveLockQueueBag* ms = reinterpret_cast<RecursiveLockQueueBag*>(pthread_getspecific(recursiveLockWithDispatchQueueTLSKey));
if (!ms)
{
ms = new RecursiveLockQueueBag();
pthread_setspecific(recursiveLockWithDispatchQueueTLSKey, reinterpret_cast<const void*>(ms));
}
const void* const vpq = reinterpret_cast<const void*>((__bridge const void*)q);
BOOL alreadyOn = NO;
if (checkAndPushNotPop)
{
alreadyOn = (ms->count(vpq) > 0);
if (!alreadyOn)
{
ms->insert(vpq);
}
}
else
{
ms->erase(vpq);
}
return alreadyOn;
}
void dispatch_recursive_sync(dispatch_queue_t queue, dispatch_block_t block)
{
if (queueStackCheck(queue, YES))
{
block();
}
else
{
#try
{
dispatch_sync(queue, block);
}
#finally
{
queueStackCheck(queue, NO);
}
}
}
#implementation MyAppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
dispatch_queue_t a = dispatch_queue_create("a", DISPATCH_QUEUE_SERIAL);
dispatch_queue_t b = dispatch_queue_create("b", DISPATCH_QUEUE_SERIAL);
dispatch_queue_t c = dispatch_queue_create("c", DISPATCH_QUEUE_SERIAL);
//dispatch_set_target_queue(a, c);
dispatch_recursive_sync(a, ^{
dispatch_recursive_sync(b, ^{
dispatch_recursive_sync(c, ^{
dispatch_recursive_sync(a, ^{
dispatch_recursive_sync(b, ^{
dispatch_recursive_sync(c, ^{
dispatch_recursive_sync(a, ^{
NSLog(#"got there");
});
});
});
});
});
});
});
}
#end
This is the lowest-overhead implementation I could think of in a few minutes. I used C++ to avoid message sending overhead. It requires that all uses of the queue use this function. This can be useful when there's a private queue protecting internal state of an object (i.e. where the queue is private and therefore guaranteed not to be retargeted, and where you can easily ensure that all consumers of the queue use dispatch_recursive_sync.
I would like to know if an instance implements a specific method. I could use respondsToSelector: but it returns YES if the instance inherits the method...
I could loop through the methods of class_copyMethodList(), but since I might want to check a lot of instances, I wanted to know if there was a simpler solution (like repondsToSelector:, but restricted to the class itself...)
edit: since I really think there is no function or method doing that, I wrote mine. Thanks for your answers, here is the method if it can be of any use :
+ (BOOL)class:(Class)aClass implementsSelector:(SEL)aSelector
{
Method *methods;
unsigned int count;
unsigned int i;
methods = class_copyMethodList(aClass, &count);
BOOL implementsSelector = NO;
for (i = 0; i < count; i++) {
if (sel_isEqual(method_getName(methods[i]), aSelector)) {
implementsSelector = YES;
break;
}
}
free(methods);
return implementsSelector;
}
It's probably easier to check whether the method your own class returns is the same or different than the method your superclass returns.
if ([[obj class] instanceMethodForSelector:sel] != [[obj superclass] instanceMethodForSelector:sel]) {
NSLog(#"%# directly implements %#", [obj class], NSStringFromSelector(sel));
}
instance responds and super does not:
-(BOOL) declaresSelector:(SEL)inSelector {
return [self respondsToSelector:inSelector] && ![super respondsToSelector:inSelector];
}
instance responds and is different than super:
-(BOOL) implementsSelector:(SEL)inSelector {
return [self respondsToSelector:inSelector] && !( [super respondsToSelector:inSelector] && [self methodForSelector:inSelector] == [super methodForSelector:inSelector] );
}
According to Apple documents you should call respondsToSelector before methodForSelector.
You can use reflection to do that.
I'm getting used to OCMock. Coming from a Java/JMock background I'm now looking for the ability to say [[[myMock stub] returnValueFromCustomMethod] someMockedMethod]; where returnValueFromCustomMethod is defined in the test class. I was originally thinking something along the terms of [[[myMock stub] usingSelector:#selector(myMethod:)] someMockedMethod]; but after writing I wonder if my first approach makes more sense. Either way, could someone show me if and how this can be done?
My original answer was off-track: OCMock doesn't support this! If you wanted to change OCMock to support this, you would need to do something like adding a BOOL returnValueIsFromInvocation field to OCMockRecorder, and add a method to set this up:
- (id)andReturnResultOfInvocation:(NSInvocation *)anInvocation {
returnValueIsFromInvocation = YES;
returnValueIsBoxed = NO;
returnValueShouldBeThrown = NO;
[returnValue autorelease];
returnValue = [anInvocation retain];
return self;
}
Then teach setUpReturnValue to call the invocation (changes are in bold):
- (void)setUpReturnValue:(NSInvocation *)anInvocation
{
if (returnValueIsFromInvocation) {
NSInvocation *returnValueInvocation = (NSInvocation *)returnValue;
[returnValueInvocation invoke];
void *buffer = malloc([[anInvocation methodSignature] methodReturnLength]);
[returnValueInvocation getValue:buffer];
[anInvocation setReturnValue:buffer];
free(buffer);
}
else if(returnValueShouldBeThrown)
{
#throw returnValue;
}
else if(returnValueIsBoxed)
{
if(strcmp([[anInvocation methodSignature] methodReturnType],
[(NSValue *)returnValue objCType]) != 0)
[NSException raise:NSInvalidArgumentException
format:#"Return value does not match method signature."];
void *buffer = malloc([[anInvocation methodSignature] methodReturnLength]);
[returnValue getValue:buffer];
[anInvocation setReturnValue:buffer];
free(buffer);
}
else
{
const char *returnType = [[anInvocation methodSignature] methodReturnType];
const char *returnTypeWithoutQualifiers = returnType + (strlen(returnType) - 1);
if(strcmp(returnTypeWithoutQualifiers, #encode(id)) == 0)
[anInvocation setReturnValue:&returnValue];
}
}
This change is difficult to do by introducing subclasses because you have to override the methods that return OCMockRecorders (like stub, expect and so on) but the concrete subclasses of OCMockObject (OCClassMockObject and OCProtocolMockObject) are hidden by the framework.