Force deletion of singleton in test code that was created with dispatch_once

Question

I\'m writing some unit test code for a model class and want to simulate the behavior of the class during app exit and relaunch. I could achieve this by deleting and re-allocing

Answer 1

sure something like this would be fine for unit testing, you can turn it off for prod:

static MyModel *singleton = nil;

+ (id) sharedInstance
{   
   if(!singleton)
    {
        singleton = [self new];
    }
    return singleton;
}
+ (void)resetSingleton
{
    [singlelton release];
    singleton = nil;
}

Answer 2

static MyModel *singleton = nil;
static dispatch_once_t onceToken;

+ (instancetype) sharedInstance
{
    dispatch_once(&onceToken, ^ {
        if (singleton==nil){
            singleton = [[MyModel alloc] initSharedInstance];
        }
    });
    return singleton;
}

+(void)setSharedInstance:(MyModel *)instance {
    onceToken = 0;
    singleton = instance;
}

Nil it:

[MyModel setSharedInstance:nil];

Note that you can also set it to an arbitrary class to mock it.

[MyModel setSharedInstance:someMock];