Hands-On: First Virtual Test Execution

cmake_minimum_required(VERSION 3.20)
project(SpeedController_SiL C)

# SiL build preset: x86-64 host, with coverage
set(CMAKE_C_STANDARD 99)

add_compile_options(-O0 -g --coverage -fprofile-arcs -ftest-coverage
                    -DSIL_BUILD=1  # disables hardware-specific code
                    -Wall -Wextra)
add_link_options(--coverage)

# Production source files (same as target build)
set(PROD_SOURCES
    src/SpeedController.c
    src/SpeedController_data.c
    src/FaultManager.c
)

# SiL stub files (replace MCAL hardware drivers)
set(STUB_SOURCES
    stubs/Adc_Stub.c
    stubs/Can_Stub.c
    stubs/Dio_Stub.c
    stubs/Os_Stub.c
)

add_library(SpeedController_sil SHARED
    ${PROD_SOURCES} ${STUB_SOURCES}
)

target_include_directories(SpeedController_sil PUBLIC
    include/
    include/autosar/
    stubs/
)

"""SiL test suite for SpeedController component."""
import ctypes
import pytest
import os

LIB_PATH = os.path.join(os.path.dirname(__file__),
                         "../build/libSpeedController_sil.so")

@pytest.fixture(scope="module")
def sil():
    """Load SiL shared library once per test module."""
    lib = ctypes.CDLL(LIB_PATH)
    # Declare function signatures
    lib.SpeedController_Init.restype  = None
    lib.SpeedController_Step.restype  = None
    lib.SiL_SetSpeedRef.argtypes       = [ctypes.c_float]
    lib.SiL_SetVehicleSpeed.argtypes   = [ctypes.c_float]
    lib.SiL_GetPedalRequest.restype    = ctypes.c_float
    lib.SiL_GetFaultActive.restype     = ctypes.c_uint8
    lib.SpeedController_Init()
    return lib

def step(sil, speed_ref: float, vehicle_speed: float) -> dict:
    sil.SiL_SetSpeedRef(ctypes.c_float(speed_ref))
    sil.SiL_SetVehicleSpeed(ctypes.c_float(vehicle_speed))
    sil.SpeedController_Step()
    return {
        "pedal": sil.SiL_GetPedalRequest(),
        "fault": bool(sil.SiL_GetFaultActive())
    }

class TestSpeedControllerNominal:
    def test_zero_error_zero_pedal(self, sil):
        """When speed matches reference, pedal should be near zero."""
        out = step(sil, speed_ref=50.0, vehicle_speed=50.0)
        assert abs(out["pedal"]) < 1.0
        assert out["fault"] == False

    def test_positive_error_positive_pedal(self, sil):
        """When vehicle is slower than reference, pedal should be positive."""
        out = step(sil, speed_ref=80.0, vehicle_speed=60.0)
        assert out["pedal"] > 0.0

    def test_speed_above_limit_triggers_fault(self, sil):
        """Speed above 120 km/h limit must activate fault flag."""
        out = step(sil, speed_ref=130.0, vehicle_speed=125.0)
        assert out["fault"] == True