Macros for blocking on asynchronous methods in iOS Unit Tests. See http://dadabeatnik.wordpress.com/2013/09/12/xcode-and-asynchronous-unit-testing/

BlockMacros.h

// Macro - Set the flag for block completion
#define StartBlock() __block BOOL waitingForBlock = YES

// Macro - Set the flag to stop the loop
#define EndBlock() waitingForBlock = NO

// Macro - Wait and loop until flag is set
#define WaitUntilBlockCompletes() WaitWhile(waitingForBlock)

// Macro - Wait for condition to be NO/false in blocks and asynchronous calls
// Each test should have its own instance of a BOOL condition because of non-thread safe operations
#define WaitWhile(condition) \
do { \
    while(condition) { \
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.1]]; \
    } \
} while(0)