src/connectivity/bluetooth/core/bt-host/testing/test_controller.h

// Copyright 2017 The Fuchsia 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 SRC_CONNECTIVITY_BLUETOOTH_CORE_BT_HOST_TESTING_TEST_CONTROLLER_H_
#define SRC_CONNECTIVITY_BLUETOOTH_CORE_BT_HOST_TESTING_TEST_CONTROLLER_H_

#include <fbl/macros.h>
#include <lib/async/dispatcher.h>
#include <lib/fit/function.h>

#include <queue>
#include <vector>

#include "src/connectivity/bluetooth/core/bt-host/common/byte_buffer.h"
#include "src/connectivity/bluetooth/core/bt-host/hci/hci.h"
#include "src/connectivity/bluetooth/core/bt-host/testing/fake_controller_base.h"

namespace bt {
namespace testing {

// A CommandTransaction is used to set up an expectation for a command channel
// packet and the events that should be sent back in response to it.
class CommandTransaction final {
 public:
  CommandTransaction() = default;
  CommandTransaction(const ByteBuffer& expected,
                     const std::vector<const ByteBuffer*>& replies);

  // Match by opcode only.
  CommandTransaction(hci::OpCode expected_opcode,
                     const std::vector<const ByteBuffer*>& replies);

  // Move constructor and assignment operator.
  CommandTransaction(CommandTransaction&& other) = default;
  CommandTransaction& operator=(CommandTransaction&& other) = default;

  // Returns true if the transaction matches the given HCI command packet.
  bool Match(const BufferView& cmd);

 private:
  friend class TestController;

  bool prefix_ = false;
  DynamicByteBuffer expected_;
  std::queue<DynamicByteBuffer> replies_;

  DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(CommandTransaction);
};

// TestController allows unit tests to set up an expected sequence of HCI
// commands and any events that should be sent back in response. The code
// internally verifies each received HCI command using gtest ASSERT_* macros.
class TestController : public FakeControllerBase {
 public:
  TestController();
  ~TestController() override;

  // Queues a transaction into the TestController's expected command queue. Each
  // packet received through the command channel endpoint will be verified
  // against the next expected transaction in the queue. A mismatch will cause a
  // fatal assertion. On a match, TestController will send back the replies
  // provided in the transaction.
  void QueueCommandTransaction(CommandTransaction transaction);
  void QueueCommandTransaction(const ByteBuffer& expected,
                               const std::vector<const ByteBuffer*>& replies);

  // Callback to invoke when a packet is received over the data channel. Care
  // should be taken to ensure that a callback with a reference to test case
  // variables is not invoked when tearing down.
  using DataCallback = fit::function<void(const ByteBuffer& packet)>;
  void SetDataCallback(DataCallback callback, async_dispatcher_t* dispatcher);
  void ClearDataCallback();

  // Callback invoked when a transaction completes. Care should be taken to
  // ensure that a callback with a reference to test case variables is not
  // invoked when tearing down.
  using TransactionCallback = fit::function<void(const ByteBuffer& rx)>;
  void SetTransactionCallback(TransactionCallback callback,
                              async_dispatcher_t* dispatcher);
  void SetTransactionCallback(fit::closure callback,
                              async_dispatcher_t* dispatcher);
  void ClearTransactionCallback();

 private:
  // FakeControllerBase overrides:
  void OnCommandPacketReceived(
      const PacketView<hci::CommandHeader>& command_packet) override;
  void OnACLDataPacketReceived(const ByteBuffer& acl_data_packet) override;

  std::queue<CommandTransaction> cmd_transactions_;
  DataCallback data_callback_;
  async_dispatcher_t* data_dispatcher_;
  TransactionCallback transaction_callback_;
  async_dispatcher_t* transaction_dispatcher_;

  DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(TestController);
};

}  // namespace testing
}  // namespace bt

#endif  // SRC_CONNECTIVITY_BLUETOOTH_CORE_BT_HOST_TESTING_TEST_CONTROLLER_H_