fix: ios:bad memory access for concurrent promises, support reload

Author: jpudysz

ios/MockLocationDetector.h

@@ -5,4 +5,5 @@
     @property CLLocationManager *locationManager;
     @property RCTPromiseResolveBlock resolve;
     @property RCTPromiseRejectBlock reject;
+    @property NSNumber *cachedIsLocationMocked;
 @end

ios/MockLocationDetector.mm

@@ -11,21 +11,25 @@ @implementation MockLocationDetector
 
 RCT_EXPORT_METHOD(isMockingLocation:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject) {
     dispatch_async(dispatch_get_main_queue(), ^{
+        if(![self getCachedVersionOrFail:resolve reject:reject]) {
+            return;
+        }
+
         if ([self checkIfGPSIsEnabled] == NO) {
             reject(@"0", @"GPS is not enabled", nil);
-            
+
             return;
         }
-        
+
         if ([self hasLocationPermission] == NO) {
             reject(@"1", @"You have no permission to access location", nil);
-            
+
             return;
         }
 
         self.resolve = resolve;
         self.reject = reject;
-        
+
         self.locationManager = [[CLLocationManager alloc] init];
         self.locationManager.delegate = self;
 
@@ -46,6 +50,7 @@ - (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray
             @"isLocationMocked": @(sourceInformation.isSimulatedBySoftware)
         };
 
+        self.cachedIsLocationMocked = [NSNumber numberWithBool:sourceInformation.isSimulatedBySoftware];
         self.resolve(dict);
     } else {
         self.reject(@"2", @"Couldn't determine if location is mocked", nil);
@@ -64,6 +69,32 @@ - (void)cleanUp {
     self.locationManager = nil;
     self.resolve = nil;
     self.reject = nil;
+    self.cachedIsLocationMocked = nil;
+}
+
+- (void)dealloc {
+    [self cleanUp];
+}
+
+- (BOOL)getCachedVersionOrFail:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject {
+    if (!self.resolve && !self.reject) {
+        return YES;
+    }
+
+    // other promise in progress
+    if (self.cachedIsLocationMocked != nil) {
+        NSDictionary *dict = @{
+            @"isLocationMocked": @([self.cachedIsLocationMocked boolValue])
+        };
+
+        resolve(dict);
+
+        return NO;
+    }
+
+    reject(@"2", @"Couldn't determine if location is mocked", nil);
+
+    return NO;
 }
 
 - (BOOL)checkIfGPSIsEnabled {
@@ -72,7 +103,7 @@ - (BOOL)checkIfGPSIsEnabled {
 
 - (BOOL)hasLocationPermission {
     CLAuthorizationStatus status = [CLLocationManager authorizationStatus];
-    
+
     return status == kCLAuthorizationStatusAuthorizedAlways || status == kCLAuthorizationStatusAuthorizedWhenInUse;
 }