Work on RCTFont SIGABRT crash

AppDelegate.m

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

#import "AppDelegate.h"

#import <React/RCTBundleURLProvider.h>
#import <React/RCTRootView.h>
#import <React/RCTBridge+Private.h>

@interface AppDelegate () <RCTBridgeDelegate>

@property (nonatomic) RCTBridge *rctBridge;

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  self.rctBridge = [[RCTBridge alloc] initWithDelegate:self launchOptions:launchOptions];
  RCTRootView *rootView = [[RCTRootView alloc] initWithBridge:self.rctBridge moduleName:@"myapp" initialProperties:nil];
  rootView.backgroundColor = [[UIColor alloc] initWithRed:1.0f green:1.0f blue:1.0f alpha:1];

  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  UIViewController *rootViewController = [UIViewController new];
  rootViewController.view = rootView;
  self.window.rootViewController = rootViewController;
  [self.window makeKeyAndVisible];
  return YES;
}

- (void)applicationWillTerminate:(UIApplication *)application
{
  RCTBridge *batchedBridge = self.rctBridge.batchedBridge;
  [self.rctBridge invalidate];
  
  NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
  NSArray<NSRunLoopMode> *allModes = CFBridgingRelease(CFRunLoopCopyAllModes(runLoop.getCFRunLoop));
  while (batchedBridge.moduleClasses) {
    for (NSRunLoopMode mode in allModes) {
      [runLoop runMode:mode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.1]];
    }
  }
}

#pragma mark - RCTBridgeDelegate

- (NSURL *)sourceURLForBridge:(RCTBridge *)bridge
{
  return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index" fallbackResource:nil];
}

@end

Could you give a mini run-through on how this works? Or if you got it from another source, could you provide a link?

I've been getting this problem in prod more and more, so would really appreciate it. Thanks.

@mujavidb If you create your app with command create-react-native-app, you can modify your AppDelegate.m as this gist. For more explanation please see this issue.