iOS TestCase for method which includes NS Timer [duplicate] - ios

Question

This question already has answers here:
XCTest and asynchronous testing in Xcode 6
(4 answers)
Closed 7 years ago.
I have a IBAction in my view controller which looks like this
-(IBAction)signUpAction:(id)sender
{
AppDelegate *appDel = [[UIApplication sharedApplication]delegate];
//check for internet Connection
if(appDel.isReachable)
{
//Internet Connection available
//perform animation od buttons and imagie view
[self fallDownAnimation];
//after animation perform model segue to corresponding view controller
NSTimer* timer = [NSTimer scheduledTimerWithTimeInterval:0.8f target:self selector:#selector(performRegistrationPageSegue) userInfo:nil repeats:NO];
[[NSRunLoop mainRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
}
else
{
//No internet Connection
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:ALERT_VIEW_TITLE message:#"No Internet Connection" delegate:self cancelButtonTitle:nil otherButtonTitles:#"Okay", nil];
[alert show];
}
}
-(void)performRegistrationPageSegue{
[self performSegueWithIdentifier:#"registerVCSegue" sender:self];
}
I want to write a test case on signUpAction method and verify if the Segue is performed. Since it has a timer the test case i have written is failing.
I Need a way to test the following condition
My Current Testcase method is
-(void)testRegisterViewControllerSegueOnAvailableInternetConnection{
AppDelegate *appDel = [[UIApplication sharedApplication]delegate];
appDel.isReachable = YES;
id loginMock = [OCMockObject partialMockForObject:_initialViewControllerToTest];
[[loginMock expect] performSegueWithIdentifier:#"registerVCSegue" sender:[OCMArg any]];
[loginMock performSelectorOnMainThread:#selector(signUpAction:) withObject:_initialViewControllerToTest.signUpButton waitUntilDone:YES];
XCTAssert([loginMock verify],#"Segue to Register Page not Performed on Sign Up Click");
}

Answer 1

You need to enter the event loop for a period of time, so that the timer event can be processed. It is basically not possible to fully regression test code without doing this. Here is a simplified method:
// Wait inside the event loop for a period of time indicated in seconds
+ (void) waitFor:(NSTimeInterval)maxWaitTime
{
int numSeconds = (int) round(maxWaitTime);
if (numSeconds < 1) {
numSeconds = 1;
}
for ( ; numSeconds > 0 ; numSeconds--) #autoreleasepool {
const int maxMS = 1000;
const int incrMS = 1;
const double seconds = 1.0 / (maxMS / incrMS);
for (int ms = 0 ; ms < maxMS; ms += incrMS) #autoreleasepool {
// One pass through the run loop for each time interval
NSDate *maxDate = [NSDate dateWithTimeIntervalSinceNow:seconds];
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:maxDate];
}
}
return;
}
A more complex impl with a selector that can be called to return when a test condition is true:
+ (BOOL) waitUntilTrue:(id)object
selector:(SEL)selector
maxWaitTime:(NSTimeInterval)maxWaitTime
{
NSAssert(object, #"object is nil");
NSAssert(selector, #"selector is nil");
NSMethodSignature *aSignature = [[object class] instanceMethodSignatureForSelector:selector];
NSInvocation *anInvocation = [NSInvocation invocationWithMethodSignature:aSignature];
[anInvocation setSelector:selector];
[anInvocation setTarget:object];
// Invoke test condition method once before the timing loop is entered, so that the
// event loop will not be entered if the condition is initially TRUE.
BOOL state;
[anInvocation invoke];
[anInvocation getReturnValue:&state];
if (state) {
return TRUE;
}
// The condition is FALSE, so enter the event loop and wait for 1 second
// each iteration through the loop. The logic below makes sure that the
// 1 second wait will be done at least once, even if wait time is less
// than a full second.
int numSeconds = (int) round(maxWaitTime);
if (numSeconds < 1) {
numSeconds = 1;
}
for ( ; numSeconds > 0 ; numSeconds--) #autoreleasepool {
NSDate *maxDate = [NSDate dateWithTimeIntervalSinceNow:1.0];
[[NSRunLoop currentRunLoop] runUntilDate:maxDate];
[anInvocation invoke];
[anInvocation getReturnValue:&state];
if (state) {
return TRUE;
}
}
return FALSE;
}