pw::i2c::MockMessageInitiator Class Reference

Overview

A generic mocked backend for pw::i2c::Initiator that's specifically designed to make it easier to develop I2C device drivers. pw::i2c::MessageMockInitiator compares actual I2C transactions against expected transactions. The expected transactions are represented as a list of pw::i2c::MockMessageTransaction instances that are passed as arguments in the pw::i2c::MessageMockInitiator constructor. Each consecutive call to pw::i2c::MockMessageInitiator iterates to the next expected transaction. pw::i2c::MockMessageInitiator::Finalize() indicates whether the actual transactions matched the expected transactions.

pw::i2c::MessageMockInitiator is intended to be used within GoogleTest tests. See

embed:rst:inline :ref:`module-pw_unit_test` 

.

#include <chrono>
 
#include "pw_bytes/array.h"
#include "pw_i2c/address.h"
#include "pw_i2c/initiator_message_mock.h"
#include "pw_i2c/message.h"
#include "pw_result/result.h"
#include "pw_unit_test/framework.h"
 
using namespace std::chrono_literals;
 
namespace {
 
TEST(I2CTestSuite, I2CReadRegisterTestCase) {
  constexpr Address kTestDeviceAddress = Address::SevenBit<0x3F>();
  constexpr auto kExpectedWrite1 = bytes::Array<0x42>();
  constexpr auto kExpectedRead1 = bytes::Array<1, 2>();
 
  auto expected_transactions = MakeExpectedTransactionArray({
      MockMessageTransaction(
          OkStatus(),
          MakeExpectedMessageArray({
              MockWriteMessage(OkStatus(), kTestDeviceAddress,
                               kExpectedWrite1),
              MockReadMessage(OkStatus(), kTestDeviceAddress,
                               kExpectedRead1),
          }),
          kI2cTransactionTimeout),
  });
  MockMessageInitiator initiator(expected_transactions);
  std::array<std::byte, kExpectedRead1.size()> read1;
  EXPECT_EQ(initiator.WriteReadFor(kTestDeviceAddress, kExpectedWrite1,
            read1, kI2cTransactionTimeout), OkStatus());
  EXPECT_TRUE(pw::containers::Equal(read1, kExpectedRead1));
  EXPECT_EQ(initiator.Finalize(), OkStatus());
}
 
}

Inheritance diagram for pw::i2c::MockMessageInitiator:

Public Member Functions
	MockMessageInitiator (span< MockMessageTransaction > transaction_list)
Status	Finalize () const
	~MockMessageInitiator () override
Public Member Functions inherited from pw::i2c::Initiator
constexpr	Initiator ()
constexpr	Initiator (Feature supported_features)
Status	WriteReadFor (Address device_address, ConstByteSpan tx_buffer, ByteSpan rx_buffer, chrono::SystemClock::duration timeout)
Status	TransferFor (span< const Message > messages, chrono::SystemClock::duration timeout)
Status	WriteReadFor (Address device_address, const void *tx_buffer, size_t tx_size_bytes, void *rx_buffer, size_t rx_size_bytes, chrono::SystemClock::duration timeout)
Status	WriteFor (Address device_address, ConstByteSpan tx_buffer, chrono::SystemClock::duration timeout)
Status	WriteFor (Address device_address, const void *tx_buffer, size_t tx_size_bytes, chrono::SystemClock::duration timeout)
Status	ReadFor (Address device_address, ByteSpan rx_buffer, chrono::SystemClock::duration timeout)
Status	ReadFor (Address device_address, void *rx_buffer, size_t rx_size_bytes, chrono::SystemClock::duration timeout)
Status	ProbeDeviceFor (Address device_address, chrono::SystemClock::duration timeout)

Additional Inherited Members
Public Types inherited from pw::i2c::Initiator
enum class	Feature : int { kStandard = 0 , kTenBit = (1 << 0) , kNoStart = (1 << 1) }
	Defined set of supported i2c features.

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The documentation for this class was generated from the following file:

• pw_i2c/public/pw_i2c/initiator_message_mock.h