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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
#ifndef IOS_TESTING_SCOPED_BLOCK_SWIZZLER_H_
#define IOS_TESTING_SCOPED_BLOCK_SWIZZLER_H_
#include <objc/runtime.h>
#include "base/macros.h"
// Helper class that replaces a method implementation with a given block.
// ScopedBlockSwizzler automatically swizzles when it is constructed and
// reinstalls the original method implementation when it goes out of scope.
class ScopedBlockSwizzler {
public:
// Constructs a new ScopedBlockSwizzler object and replaces the implementation
// of |selector| on the |target| class with the given |block|.
// ScopedBlockSwizzler first tries to swizzle a class method; if one is not
// found, it tries to swizzle an instance method. It is an error to pass a
// |selector| that does not exist on the |target| class.
ScopedBlockSwizzler(Class target, SEL selector, id block);
// Constructs a new ScopedBlockSwizzler object and replaces the implementation
// of |selector| on the |target| class with the given |block|.
// |class_method| specifies if the swizzled method is a class method (YES) or
// an instance method (NO). This can be use to disambiguate if the class
// contains both method types with the same selector.
ScopedBlockSwizzler(Class target, SEL selector, id block, BOOL class_method);
ScopedBlockSwizzler(const ScopedBlockSwizzler&) = delete;
ScopedBlockSwizzler& operator=(const ScopedBlockSwizzler&) = delete;
// Destroys the ScopedBlockSwizzler object, removing the swizzled method and
// reinstalling the original method implementation.
virtual ~ScopedBlockSwizzler();
private:
// The method that is to be swizzled. Can be either a class method or an
// instance method.
Method method_;
// The original implementation of the swizzled method, saved so that it can be
// reinstalled when this object goes out of scope.
IMP original_imp_;
};
#endif // IOS_TESTING_SCOPED_BLOCK_SWIZZLER_H_