base/test/scoped_feature_list.h

// Copyright 2016 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 BASE_TEST_SCOPED_FEATURE_LIST_H_
#define BASE_TEST_SCOPED_FEATURE_LIST_H_

#include "base/feature_list.h"

namespace base {
namespace test {

// ScopedFeatureList resets the global FeatureList instance to a new empty
// instance and restores the original instance upon destruction.
// Note: Re-using the same object is not allowed. To reset the feature
// list and initialize it anew, destroy an existing scoped list and init
// a new one.
class ScopedFeatureList final {
 public:
  ScopedFeatureList();
  ~ScopedFeatureList();

  // Initializes and registers a FeatureList instance with no overrides.
  void Init();

  // Initializes and registers the given FeatureList instance.
  void InitWithFeatureList(std::unique_ptr<FeatureList> feature_list);

  // Initializes and registers a FeatureList instance with the given
  // enabled and disabled features (comma-separated names).
  void InitFromCommandLine(const std::string& enable_features,
                           const std::string& disable_features);

  // Initializes and registers a FeatureList instance enabling a single
  // feature.
  void InitAndEnableFeature(const base::Feature& feature);

  // Initializes and registers a FeatureList instance disabling a single
  // feature.
  void InitAndDisableFeature(const base::Feature& feature);

 private:
  std::unique_ptr<FeatureList> original_feature_list_;

  DISALLOW_COPY_AND_ASSIGN(ScopedFeatureList);
};

}  // namespace test
}  // namespace base

#endif  // BASE_TEST_SCOPED_FEATURE_LIST_H_