appium-webdriveragent/WebDriverAgentLib/Utilities/FBReflectionUtils.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 "FBReflectionUtils.h"

#import <objc/runtime.h>

void FBReplaceMethod(Class class, SEL originalSelector, SEL swizzledSelector) {
  Method originalMethod = class_getInstanceMethod(class, originalSelector);
  Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);

  BOOL didAddMethod =
  class_addMethod(class,
                  originalSelector,
                  method_getImplementation(swizzledMethod),
                  method_getTypeEncoding(swizzledMethod));

  if (didAddMethod) {
    class_replaceMethod(class,
                        swizzledSelector,
                        method_getImplementation(originalMethod),
                        method_getTypeEncoding(originalMethod));
  } else {
    method_exchangeImplementations(originalMethod, swizzledMethod);
  }
}