C++ components unit test framework (#9284)

Co-authored-by: J. Nick Koston <nick@home-assistant.io>
Co-authored-by: J. Nick Koston <nick@koston.org>

tests/components/uart/uart_component.cpp

@@ -0,0 +1,73 @@
+#include "common.h"
+
+namespace esphome::uart::testing {
+
+TEST(UARTComponentTest, SetGetBaudRate) {
+  MockUARTComponent mock;
+  mock.set_baud_rate(38400);
+  EXPECT_EQ(mock.get_baud_rate(), 38400);
+}
+
+TEST(UARTComponentTest, SetGetStopBits) {
+  MockUARTComponent mock;
+  mock.set_stop_bits(2);
+  EXPECT_EQ(mock.get_stop_bits(), 2);
+}
+
+TEST(UARTComponentTest, SetGetDataBits) {
+  MockUARTComponent mock;
+  mock.set_data_bits(7);
+  EXPECT_EQ(mock.get_data_bits(), 7);
+}
+
+TEST(UARTComponentTest, SetGetParity) {
+  MockUARTComponent mock;
+  mock.set_parity(UARTParityOptions::UART_CONFIG_PARITY_EVEN);
+  EXPECT_EQ(mock.get_parity(), UARTParityOptions::UART_CONFIG_PARITY_EVEN);
+}
+
+TEST(UARTComponentTest, SetGetRxBufferSize) {
+  MockUARTComponent mock;
+  mock.set_rx_buffer_size(128);
+  EXPECT_EQ(mock.get_rx_buffer_size(), 128);
+}
+
+TEST(UARTComponentTest, WriteArrayVector) {
+  MockUARTComponent mock;
+  std::vector<uint8_t> data = {10, 20, 30};
+  mock.write_array(data);
+  EXPECT_EQ(mock.written_data, data);
+}
+TEST(UARTComponentTest, WriteByte) {
+  MockUARTComponent mock;
+  uint8_t byte = 0x79;
+  mock.write_byte(byte);
+  EXPECT_EQ(mock.written_data.size(), 1);
+  EXPECT_EQ(mock.written_data[0], byte);
+}
+
+TEST(UARTComponentTest, WriteStr) {
+  MockUARTComponent mock;
+  const char *str = "Hello";
+  std::vector<uint8_t> captured;
+  mock.write_str(str);
+  EXPECT_EQ(mock.written_data.size(), strlen(str));
+  EXPECT_EQ(0, strncmp(str, (const char *) mock.written_data.data(), mock.written_data.size()));
+}
+
+// Tests for wrapper methods forwarding to pure virtual read_array
+TEST(UARTComponentTest, ReadByteSuccess) {
+  MockUARTComponent mock;
+  uint8_t value = 0;
+  EXPECT_CALL(mock, read_array(&value, 1)).WillOnce(Return(true));
+  EXPECT_TRUE(mock.read_byte(&value));
+}
+
+TEST(UARTComponentTest, ReadByteFailure) {
+  MockUARTComponent mock;
+  uint8_t value = 0xFF;
+  EXPECT_CALL(mock, read_array(&value, 1)).WillOnce(Return(false));
+  EXPECT_FALSE(mock.read_byte(&value));
+}
+
+}  // namespace esphome::uart::testing