break out acceptFrame, test CanListener (#4001)

firmware/controllers/can/can_listener.h

@@ -17,7 +17,7 @@ public:
 	}
 
 	CanListener* processFrame(const CANRxFrame& frame, efitick_t nowNt) {
-		if (CAN_ID(frame) == m_id) {
+		if (acceptFrame(frame)) {
 			decodeFrame(frame, nowNt);
 		}
 
@@ -36,10 +36,17 @@ public:
 		return m_next;
 	}
 
+	// Return true if the provided frame should be accepted for processing by the listener.
+	// Override if you need more complex logic than comparing to a single ID.
+	virtual bool acceptFrame(const CANRxFrame& frame) const {
+		return CAN_ID(frame) == m_id;
+	}
+
 protected:
 	virtual void decodeFrame(const CANRxFrame& frame, efitick_t nowNt) = 0;
-	CanListener* m_next = nullptr;
 
 private:
+	CanListener* m_next = nullptr;
+
 	const uint32_t m_id;
 };

unit_tests/tests/test_can_rx.cpp

@@ -0,0 +1,67 @@
+#include "pch.h"
+
+#include "can_listener.h"
+
+using ::testing::StrictMock;
+using ::testing::_;
+
+class MockCanListener : public CanListener {
+public:
+	MockCanListener(uint32_t id) : CanListener(id) { }
+
+	MOCK_METHOD(void, decodeFrame, (const CANRxFrame& frame, efitick_t nowNt), (override));
+	MOCK_METHOD(bool, acceptFrame, (const CANRxFrame& frame), (const, override));
+};
+
+TEST(CanListener, FrameAccepted) {
+	StrictMock<MockCanListener> dut(0x123);
+
+	CANRxFrame frame;
+
+	// Accept should be called, returns true
+	EXPECT_CALL(dut, acceptFrame(_)).WillOnce(Return(true));
+
+	// Because accept returns true, decode is called
+	EXPECT_CALL(dut, decodeFrame(_, 1234));
+
+	dut.processFrame(frame, 1234);
+}
+
+TEST(CanListener, FrameNotAccepted) {
+	StrictMock<MockCanListener> dut(0x123);
+
+	CANRxFrame frame;
+
+	// Accept should be called, returns false, so decode not called
+	EXPECT_CALL(dut, acceptFrame(_)).WillOnce(Return(false));
+
+	dut.processFrame(frame, 1234);
+}
+
+struct CanListenerNoDecode : public CanListener {
+	CanListenerNoDecode(uint32_t id) : CanListener(id) { }
+
+	void decodeFrame(const CANRxFrame& frame, efitick_t nowNt) override { }
+};
+
+TEST(CanListener, FrameAcceptedChecksId) {
+	CanListenerNoDecode dut(0x123);
+
+	CANRxFrame frame;
+
+	frame.SID = 0x123;
+	frame.IDE = false;
+
+	EXPECT_TRUE(dut.acceptFrame(frame));
+}
+
+TEST(CanListener, FrameNotAcceptedChecksId) {
+	CanListenerNoDecode dut(0x123);
+
+	CANRxFrame frame;
+
+	frame.SID = 0x456;
+	frame.IDE = false;
+
+	EXPECT_FALSE(dut.acceptFrame(frame));
+}

unit_tests/tests/tests.mk

@@ -84,6 +84,7 @@ TESTS_SRC_CPP = \
 	tests/test_gpio.cpp \
 	tests/test_limp.cpp \
 	tests/trigger/test_all_triggers.cpp \
+	tests/test_can_rx.cpp \
 	tests/test_can_serial.cpp \
 	tests/test_hellen_board_id.cpp \
 	tests/sensor/test_frequency_sensor.cpp \