Unit Testing Example with OCUnit

manpreet Best Answer 3 years ago

I'm really struggling to understand unit testing. I do understand the importance of TDD, but all the examples of unit testing I read about seem to be extremely simple and trivial. For example, testing to make sure a property is set or if memory is allocated to an array. Why? If I code out ..alloc] init], do I really need to make sure it works?

I'm new to development so I'm sure I'm missing something here, especially with all the craze surrounding TDD.

I think my main issue is I can't find any practical examples. Here is a method setReminderId that seems to be a good candidate for testing. What would a useful unit test look like to make sure this is working? (using OCUnit)

- (NSNumber *)setReminderId: (NSDictionary *)reminderData
{
    NSNumber *currentReminderId = [[NSUserDefaults standardUserDefaults] objectForKey:@"currentReminderId"];
    if (currentReminderId) {
        // Increment the last reminderId
        currentReminderId = @(currentReminderId.intValue + 1);
    }
    else {
        // Set to 0 if it doesn't already exist
        currentReminderId = @0;
    }
    // Update currentReminderId to model
    [[NSUserDefaults standardUserDefaults] setObject:currentReminderId forKey:@"currentReminderId"];

    return currentReminderId;
}