replace deprecated sendSynchronousRequest:returningResponse:error: with dataTaskWithURL:completionHandler:

Author: Pavlos Vinieratos

React/Base/RCTBundleURLProvider.m

@@ -69,9 +69,16 @@ - (void)resetToDefaults
 - (BOOL)isPackagerRunning:(NSString *)host
 {
   NSURL *url = [serverRootWithHost(host) URLByAppendingPathComponent:@"status"];
-  NSURLRequest *request = [NSURLRequest requestWithURL:url];
-  NSURLResponse *response;
-  NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:NULL];
+  __block NSData *data;
+
+  dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
+  [[[NSURLSession sharedSession] dataTaskWithURL:url
+          completionHandler:^(NSData *d, NSURLResponse *response, NSError *error) {
+            data = d;
+            dispatch_semaphore_signal(semaphore);
+          }] resume];
+  dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
+
   NSString *status = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
   return [status isEqualToString:@"packager-status:running"];
 }