Mocking out CLLocationManager

CLLocationManager+MockingLocation.h

#import <CoreLocation/CoreLocation.h>

extern CLLocationDegrees kMockedLatitude;
extern CLLocationDegrees kMockedLongitude;

@interface CLLocationManager (MockingLocation)

+ (BOOL)custom_locationServicesEnabled;
+ (CLAuthorizationStatus)custom_authorizationStatus;
-(void)custom_startUpdatingLocation;
-(CLLocation *)custom_location;

@end

CLLocationManager+MockingLocation.m

#import "CLLocationManager+MockingLocation.h"

// The lat and long of the mocked current location
CLLocationDegrees kMockedLatitude = 28.5388;
CLLocationDegrees kMockedLongitude = -81.3756;

// This category implements methods that will be swizzled to replace key methods
// in CLLocationManager to mock out the user location
@implementation CLLocationManager (MockingLocation)
// replaces locationServicesEnabled;
+ (BOOL)custom_locationServicesEnabled;
{
    return YES;
}
// replaces startUpdatingLocation, will send the locationManager:didUpdateLocations: message
// to the delegate after a wait of 0.1 seconds using dispatch_after to simulate how 
// startUpdatingLocation actually works.  This will not simulate any kind of location errors
-(void)custom_startUpdatingLocation;
{
    CLLocation *usersCurrentLocation = [[CLLocation alloc] initWithLatitude:kMockedLatitude longitude:kMockedLongitude];
    
    if (self.delegate) {
        if ([self.delegate respondsToSelector:@selector(locationManager:didUpdateLocations:)]) {
            // Send the locationManager:didUpdateLocations: message to location manager after 0.1 seconds
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
                NSArray *locations = @[usersCurrentLocation];
                [self.delegate locationManager:self didUpdateLocations:locations];
            });
        }
    }
}
// replaces location, returns the mocked CLLocation object, does not current
// have any support for mocking altitude or anything other than lat/long
-(CLLocation *)custom_location;
{
    return [[CLLocation alloc] initWithLatitude:kMockedLatitude longitude:kMockedLongitude];
}
@end

CSSwizzler.h

#import <Foundation/Foundation.h>

@interface CSSwizzler : NSObject

+(void)swizzleClass:(id)cls
 replaceClassMethod:(SEL)origMethodSelector
         withMethod:(SEL)replacementMethodSelector;

+(void)swizzleClass:(id)cls
      replaceMethod:(SEL)origMethodSelector
         withMethod:(SEL)replacementMethodSelector;

+(void)swizzleClassOfInstance:(id)inst
                replaceMethod:(SEL)origMethodSelector
                   withMethod:(SEL)replacementMethodSelector;
@end

CSSwizzler.m

#import "CSSwizzler.h"
#import <objc/message.h>
#import <objc/runtime.h>

@implementation CSSwizzler

+(void)swizzleClass:(id)cls
 replaceClassMethod:(SEL)origMethodSelector
         withMethod:(SEL)replacementMethodSelector;
{
    Method origMethod = nil, altMethod = nil;
    origMethod = class_getClassMethod(cls, origMethodSelector);
    altMethod = class_getClassMethod(cls, replacementMethodSelector);
    method_exchangeImplementations(origMethod, altMethod);
}

+(void)swizzleClass:(id)cls
      replaceMethod:(SEL)origMethodSelector
         withMethod:(SEL)replacementMethodSelector;
{
    Method origMethod = nil, altMethod = nil;
    origMethod = class_getInstanceMethod(cls, origMethodSelector);
    altMethod = class_getInstanceMethod(cls, replacementMethodSelector);
    method_exchangeImplementations(origMethod, altMethod);
}

+(void)swizzleClassOfInstance:(id)inst
                replaceMethod:(SEL)origMethodSelector
                   withMethod:(SEL)replacementMethodSelector;
{
    const char *str = [[[inst class] description] UTF8String];
    Class cls = objc_getClass(str);
    Method origMethod = nil, altMethod = nil;
    origMethod = class_getInstanceMethod(cls, origMethodSelector);
    altMethod = class_getInstanceMethod(cls, replacementMethodSelector);
    method_exchangeImplementations(origMethod, altMethod);
}
@end

LocationMocker.m

#import "LocationMocker.h"
#import "CSSwizzler.h"
#import "CLLocationManager+MockingLocation.h"

@implementation LocationMocker
// This method gets automatically called as soon as this class
// is loaded
+(void) load;
{
    // locationServicesEnabled exists as both a class method
    [CSSwizzler swizzleClass:[CLLocationManager class]
          replaceClassMethod:@selector(locationServicesEnabled)
                  withMethod:@selector(custom_locationServicesEnabled)];
    
    // and an instance method on CLLocationManager, thus we will swizzle it
    // twice
    [CSSwizzler swizzleClass:[CLLocationManager class]
               replaceMethod:@selector(locationServicesEnabled)
                  withMethod:@selector(custom_locationServicesEnabled)];
    
    [CSSwizzler swizzleClass:[CLLocationManager class]
               replaceMethod:@selector(startUpdatingLocation)
                  withMethod:@selector(custom_startUpdatingLocation)];
    
    [CSSwizzler swizzleClass:[CLLocationManager class]
               replaceMethod:@selector(location)
                  withMethod:@selector(custom_location)];
}
@end

Is there a LocationMocker.h file missing? I see you import it in the LocationMocker.m

Hey @rallo, there is no need for a header as it is not imported anyhow.

You would add the following somewhere either in the .m or .h

@interface LocationMocker: NSObject

@end