A simple runloop addition to ease Asynchronous Unit Tests in ObjC

NSRunLoop+TimeOutAndFlag.h

//
//  NSRunLoop+TimeOutAndFlag.h
//
//

@interface NSRunLoop (TimeOutAndFlag)

- (void)runUntilTimeout:(NSTimeInterval)delay orFinishedFlag:(BOOL*)finished;

@end

NSRunLoop+TimeOutAndFlag.m

//
//  NSRunLoop+TimeOutAndFlag.m
//
//

#import "NSRunLoop+TimeOutAndFlag.h"

@implementation NSRunLoop (TimeOutAndFlag)

- (void)runUntilTimeout:(NSTimeInterval)delay orFinishedFlag:(BOOL*)finished;
{
    NSDate * endDate = [NSDate dateWithTimeIntervalSinceNow:delay];
    do {
        [self runMode:NSDefaultRunLoopMode beforeDate:nil];
    } while (!*finished && [endDate compare:[NSDate date]]==NSOrderedDescending);
}

@end

Request_tests.m

//
//  Request_tests.m
//
//

#import "NSRunLoop+TimeOutAndFlag.h"

@interface Request_tests : SenTestCase
@end

@implementation Request_tests

- (void) testRequest
{
    NSURLRequest * request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com"]];

    __block BOOL found;
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue]
                           completionHandler:^(NSURLResponse * response, NSData * data, NSError * error) {
                               STAssertEquals([(NSHTTPURLResponse*)response statusCode],(NSInteger)200,@"server did not respond correctly");
                               found = YES;
                           }];
    [[NSRunLoop mainRunLoop] runUntilTimeout:5 orFinishedFlag:&found];
    STAssertTrue(found,@"server did not respond in time");
}
 
@end