test_binary_log.cpp

#include "log_field.h"
#include "buffered_writer.h"

#include <gmock/gmock.h>

using ::testing::_;
using ::testing::ElementsAre;
using ::testing::StrictMock;

class MockWriter : public Writer {
public:
	MOCK_METHOD(size_t, write, (const char* buffer, size_t count), (override));
	MOCK_METHOD(size_t, flush, (), (override));
};

TEST(BinaryLogField, FieldHeader) {
	scaled_channel<int8_t, 10> channel;
	LogField field(channel, "name", "units", 2, "category");

	char buffer[89];
	StrictMock<MockWriter> bufWriter;
	EXPECT_CALL(bufWriter, write(_, 89))
		.WillOnce([&] (const char* buf, size_t count) {
			memcpy(buffer, buf, count);
			return 0;
		});

	// Should write 89 bytes
	field.writeHeader(bufWriter);

	// Expect correctly written header
	EXPECT_THAT(buffer, ElementsAre(
		1,	// type: int8_t
		// name - 34 bytes, 0 padded
		'n', 'a', 'm', 'e', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		// units - 10 bytes, 0 padded
		'u', 'n', 'i', 't', 's', 0, 0, 0, 0, 0,
		// display style: float
		0,
		// Scale = 0.1 (float)
		0x3d, 0xcc, 0xcc, 0xcd,
		// Transform - we always use 0
		0, 0, 0, 0,
		// Digits - 2, as configured
		2,
		'c', 'a', 't', 'e', 'g', 'o', 'r', 'y', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	));
}

TEST(BinaryLogField, Value) {
	scaled_channel<uint32_t, 1> testValue = 12345678;
	LogField lf(testValue, "test", "unit", 0);

	char buffer[6];
	memset(buffer, 0xAA, sizeof(buffer));

	// Should write 4 bytes
	EXPECT_EQ(4, lf.writeData(buffer));

	// Check that big endian data was written, and bytes after weren't touched
	EXPECT_THAT(buffer, ElementsAre(0x00, 0xbc, 0x61, 0x4e, 0xAA, 0xAA));
}