relay_chn/test_apps/main/test_relay_chn.c

#include "driver/gpio.h"
#include "unity.h"
#include "unity_test_utils.h"
#include "relay_chn.h" // Main header file for the relay_chn component
#include <esp_log.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include "sdkconfig.h" // For accessing CONFIG_* values

// Test GPIOs and channel IDs
// Please ensure these GPIOs are correct and suitable for your board.
// Two channels (4 GPIOs) are used as an example.
const gpio_num_t gpio_map[] = {GPIO_NUM_4, GPIO_NUM_5, GPIO_NUM_18, GPIO_NUM_19};
const uint8_t gpio_count = sizeof(gpio_map) / sizeof(gpio_map[0]);
// Assuming 2 GPIOs are used per channel
const uint8_t relay_chn_count = gpio_count / 2; 

// Retrieve inertia value from SDKconfig
#ifndef CONFIG_RELAY_CHN_OPPOSITE_INERTIA_MS
#define CONFIG_RELAY_CHN_OPPOSITE_INERTIA_MS 500 // Default if not defined in SDKconfig
#endif

const uint32_t opposite_inertia_ms = CONFIG_RELAY_CHN_OPPOSITE_INERTIA_MS;

// Tolerant delay margin to ensure operations complete, especially after inertia.
const uint32_t test_delay_margin_ms = 50; 

// --- Test Setup/Teardown Functions ---
void setUp(void) {
    ESP_LOGI("TEST_SETUP", "Running setUp for relay_chn tests.");
    // Re-create the component before each test. relay_chn_create returns esp_err_t.
    TEST_ESP_OK(relay_chn_create(gpio_map, gpio_count)); 
    // Ensure all relays are stopped at the beginning, and transition to FREE state
    for (uint8_t i = 0; i < relay_chn_count; i++) {
        relay_chn_stop(i); // relay_chn_stop returns void
        vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms)); // Wait for FREE state
    }
    ESP_LOGI("TEST_SETUP", "All channels initialized to RELAY_CHN_STATE_FREE.");
}

void tearDown(void) {
    ESP_LOGI("TEST_TEARDOWN", "Running tearDown for relay_chn tests.");
    // Stop all relays after each test, and transition to FREE state
    for (uint8_t i = 0; i < relay_chn_count; i++) {
        relay_chn_stop(i); // relay_chn_stop returns void
        vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms)); // Wait for FREE state
    }
    ESP_LOGI("TEST_TEARDOWN", "All channels returned to RELAY_CHN_STATE_FREE.");
}

// --- Basic Functionality Tests ---

// TEST_CASE 1: Test that relay channels initialize correctly to RELAY_CHN_STATE_FREE
TEST_CASE("Relay channels initialize correctly to FREE state", "[relay_chn]") {
    ESP_LOGI("TEST", "Running test: Relay channels initialize correctly to FREE state");
    for (uint8_t i = 0; i < relay_chn_count; i++) {
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(i));
    }
}

// TEST_CASE 2: Test that relays run in the forward direction and update their state
TEST_CASE("Relay channels run forward and update state", "[relay_chn]") {
    ESP_LOGI("TEST", "Running test: Relay channels run forward and update state");
    for (uint8_t i = 0; i < relay_chn_count; i++) {
        relay_chn_run_forward(i); // relay_chn_run_forward returns void
        // Short delay for state to update
        vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(i));
    }
}

// TEST_CASE 3: Test that relays run in the reverse direction and update their state
TEST_CASE("Relay channels run reverse and update state", "[relay_chn]") {
    ESP_LOGI("TEST", "Running test: Relay channels run reverse and update state");
    for (uint8_t i = 0; i < relay_chn_count; i++) {
        relay_chn_run_reverse(i); // relay_chn_run_reverse returns void
        vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(i));
    }
}

// TEST_CASE 4: Test that relays stop and transition to RELAY_CHN_STATE_FREE
// This test also verifies the transition to FREE state after a STOP command.
TEST_CASE("Relay channels stop and update to FREE state", "[relay_chn]") {
    ESP_LOGI("TEST", "Running test: Relay channels stop and update to FREE state");
    for (uint8_t i = 0; i < relay_chn_count; i++) {
        // First, run forward to test stopping and transitioning to FREE state
        relay_chn_run_forward(i); // relay_chn_run_forward returns void
        vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(i));

        // Now, issue the stop command
        relay_chn_stop(i); // relay_chn_stop returns void
        // Immediately after stop, state should be STOPPED
        vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_STOPPED, relay_chn_get_state(i));

        // Then, wait for the inertia period for it to transition to RELAY_CHN_STATE_FREE
        vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(i));
    }
}

// TEST_CASE 5: Test function calls with invalid channel IDs
// TEST_CASE("Invalid channel ID handling", "[relay_chn]") {
//     ESP_LOGI("TEST", "Running test: Invalid channel ID handling");
//     uint8_t invalid_channel_id = relay_chn_count + 1; // An ID that is out of bounds

//     // These calls are expected to return ESP_ERR_INVALID_ARG, so TEST_ASSERT_EQUAL is appropriate.
//     TEST_ASSERT_EQUAL(ESP_ERR_INVALID_ARG, relay_chn_run_forward(invalid_channel_id));
//     TEST_ASSERT_EQUAL(ESP_ERR_INVALID_ARG, relay_chn_run_reverse(invalid_channel_id));
//     TEST_ASSERT_EQUAL(ESP_ERR_INVALID_ARG, relay_chn_stop(invalid_channel_id));
    
//     // Test tilt commands only if tilt functionality is enabled
// #if CONFIG_RELAY_CHN_ENABLE_TILTING == 1
//     TEST_ASSERT_EQUAL(ESP_ERR_INVALID_ARG, relay_chn_tilt_forward(invalid_channel_id));
//     TEST_ASSERT_EQUAL(ESP_ERR_INVALID_ARG, relay_chn_tilt_reverse(invalid_channel_id));
// #endif
    
//     TEST_ASSERT_EQUAL(ESP_ERR_INVALID_ARG, relay_chn_get_state(invalid_channel_id));
// }

// TEST_CASE 6: Test independent operation of multiple relay channels
TEST_CASE("Multiple channels can operate independently", "[relay_chn]") {
    ESP_LOGI("TEST", "Running test: Multiple channels can operate independently");
    if (relay_chn_count >= 2) {
        // Start Channel 0 in forward direction
        relay_chn_run_forward(0); // relay_chn_run_forward returns void
        vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(0));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(1)); // Other channel should not be affected

        // Start Channel 1 in reverse direction
        relay_chn_run_reverse(1); // relay_chn_run_reverse returns void
        vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(0));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(1));

        // Stop Channel 0 and wait for it to become FREE
        relay_chn_stop(0); // relay_chn_stop returns void
        vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(0));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(1)); // Other channel should continue running

        // Stop Channel 1 and wait for it to become FREE
        relay_chn_stop(1); // relay_chn_stop returns void
        vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(0));
        TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(1));
    } else {
        ESP_LOGW("TEST", "Skipping 'Multiple channels can operate independently' test: Not enough channels available.");
    }
}


// ### Inertia and State Transition Tests

// This section specifically targets the inertia periods and complex state transitions as per the component's logic.

// TEST_CASE 7: Test transition from forward to reverse with inertia and state checks
// Scenario: RELAY_CHN_STATE_FORWARD -> (relay_chn_run_reverse) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_REVERSE
TEST_CASE("Forward to Reverse transition with opposite inertia", "[relay_chn][inertia]") {
    ESP_LOGI("TEST", "Running test: Forward to Reverse transition with opposite inertia");
    uint8_t ch = 0; // Channel to test

    // 1. Start in forward direction
    relay_chn_run_forward(ch); // relay_chn_run_forward returns void
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms)); // Short delay for state stabilization
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));

    // 2. Issue reverse command
    relay_chn_run_reverse(ch); // relay_chn_run_reverse returns void
    // Immediately after the command, the motor should be stopped
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms)); 
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE_PENDING, relay_chn_get_state(ch)); 

    // Wait for the inertia period (after which the reverse command will be dispatched)
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms)); 
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(ch)); // Should now be in reverse state
}

// TEST_CASE 8: Test transition from reverse to forward with inertia and state checks
// Scenario: RELAY_CHN_STATE_REVERSE -> (relay_chn_run_forward) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_FORWARD
TEST_CASE("Reverse to Forward transition with opposite inertia", "[relay_chn][inertia]") {
    ESP_LOGI("TEST", "Running test: Reverse to Forward transition with opposite inertia");
    uint8_t ch = 0;

    // 1. Start in reverse direction
    relay_chn_run_reverse(ch); // relay_chn_run_reverse returns void
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(ch));

    // 2. Issue forward command
    relay_chn_run_forward(ch); // relay_chn_run_forward returns void
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD_PENDING, relay_chn_get_state(ch));

    // Wait for inertia
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));
}

// TEST_CASE 9: Test issuing the same run command while already running (no inertia expected)
// Scenario: RELAY_CHN_STATE_FORWARD -> (relay_chn_run_forward) -> RELAY_CHN_STATE_FORWARD
TEST_CASE("Running in same direction does not incur inertia", "[relay_chn][inertia]") {
    ESP_LOGI("TEST", "Running test: Running in same direction does not incur inertia");
    uint8_t ch = 0;

    // 1. Start in forward direction
    relay_chn_run_forward(ch); // relay_chn_run_forward returns void
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));

    // 2. Issue the same forward command again
    relay_chn_run_forward(ch); // relay_chn_run_forward returns void
    // As per the code, is_direction_opposite_to_current_motion should return false, so no inertia.
    // Just a short delay to check state remains the same.
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms)); 
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));
}

// TEST_CASE 10: Test transition from FREE state to running (no inertia expected)
// Scenario: RELAY_CHN_STATE_FREE -> (relay_chn_run_forward) -> RELAY_CHN_STATE_FORWARD
TEST_CASE("FREE to Running transition without inertia", "[relay_chn][inertia]") {
    ESP_LOGI("TEST", "Running test: FREE to Running transition without inertia");
    uint8_t ch = 0;

    // setUp() should have already brought the channel to FREE state
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(ch));

    // Start in forward direction
    relay_chn_run_forward(ch); // relay_chn_run_forward returns void
    // No inertia is expected when starting from FREE state.
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));
}


// ### Tilt Functionality Tests (Conditional)

// This section will only be compiled if **`CONFIG_RELAY_CHN_ENABLE_TILTING`** is defined as **`1`** in `sdkconfig`.

#if CONFIG_RELAY_CHN_ENABLE_TILTING == 1

#define RELAY_CHN_CMD_FORWARD 1
#define RELAY_CHN_CMD_REVERSE 2

// Helper function to prepare channel for tilt tests
void prepare_channel_for_tilt(uint8_t chn_id, int initial_cmd) {
    // Ensure the channel has had a 'last_run_cmd'
    if (initial_cmd == RELAY_CHN_CMD_FORWARD) {
        relay_chn_run_forward(chn_id);
    } else { // Assuming initial_cmd is RELAY_CHN_CMD_REVERSE
        relay_chn_run_reverse(chn_id);
    }
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms)); // Allow command to process
    relay_chn_stop(chn_id); // Stop it to set last_run_cmd but return to FREE for next test
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(chn_id));
}

// TEST_CASE 11: Test transition from running forward to tilt forward
// Scenario: RELAY_CHN_STATE_FORWARD -> (relay_chn_tilt_forward) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_TILT_FORWARD
TEST_CASE("Run Forward to Tilt Forward transition with inertia", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: Run Forward to Tilt Forward transition with inertia");
    uint8_t ch = 0;

    // Prepare channel by running forward first to set last_run_cmd
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_FORWARD);

    // 1. Start in forward direction
    relay_chn_run_forward(ch); 
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));

    // 2. Issue tilt forward command
    relay_chn_tilt_forward(ch); 
    // After tilt command, it should immediately stop and then trigger inertia.
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms)); 
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_STOPPED, relay_chn_get_state(ch)); 

    // Wait for the inertia period (after which the tilt command will be dispatched)
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_FORWARD, relay_chn_get_state(ch));
}

// TEST_CASE 12: Test transition from running reverse to tilt reverse
// Scenario: RELAY_CHN_STATE_REVERSE -> (relay_chn_tilt_reverse) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_TILT_REVERSE
TEST_CASE("Run Reverse to Tilt Reverse transition with inertia", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: Run Reverse to Tilt Reverse transition with inertia");
    uint8_t ch = 0;

    // Prepare channel by running reverse first to set last_run_cmd
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_REVERSE);

    // 1. Start in reverse direction
    relay_chn_run_reverse(ch); 
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(ch));

    // 2. Issue tilt reverse command
    relay_chn_tilt_reverse(ch); 
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_STOPPED, relay_chn_get_state(ch));

    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_REVERSE, relay_chn_get_state(ch));
}

// TEST_CASE 13: Test transition from FREE state to tilt forward (now with preparation)
// Scenario: RELAY_CHN_STATE_FREE -> (prepare) -> RELAY_CHN_STATE_FREE -> (relay_chn_tilt_forward) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_TILT_FORWARD
TEST_CASE("FREE to Tilt Forward transition with inertia (prepared)", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: FREE to Tilt Forward transition with inertia (prepared)");
    uint8_t ch = 0;

    // Prepare channel by running forward first to set last_run_cmd
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_FORWARD);
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(ch)); // Ensure we are back to FREE

    // Issue tilt forward command
    relay_chn_tilt_forward(ch); 
    // From FREE state, tilt command should still incur the inertia due to the internal timer logic
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms)); 
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_FORWARD, relay_chn_get_state(ch));
}

// TEST_CASE 14: Test transition from FREE state to tilt reverse (now with preparation)
// Scenario: RELAY_CHN_STATE_FREE -> (prepare) -> RELAY_CHN_STATE_FREE -> (relay_chn_tilt_reverse) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_TILT_REVERSE
TEST_CASE("FREE to Tilt Reverse transition with inertia (prepared)", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: FREE to Tilt Reverse transition with inertia (prepared)");
    uint8_t ch = 0;

    // Prepare channel by running reverse first to set last_run_cmd
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_REVERSE);
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(ch)); // Ensure we are back to FREE

    // Issue tilt reverse command
    relay_chn_tilt_reverse(ch); 
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_REVERSE, relay_chn_get_state(ch));
}

// TEST_CASE 15: Test transition from tilt forward to run forward (inertia expected for run)
// Scenario: RELAY_CHN_STATE_TILT_FORWARD -> (relay_chn_run_forward) -> RELAY_CHN_STATE_FORWARD
TEST_CASE("Tilt Forward to Run Forward transition with inertia", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: Tilt Forward to Run Forward transition with inertia");
    uint8_t ch = 0;

    // Prepare channel by running forward first to set last_run_cmd, then tilt
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_FORWARD);
    relay_chn_tilt_forward(ch); // Go to tilt state
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_FORWARD, relay_chn_get_state(ch));

    // 2. Issue run forward command
    relay_chn_run_forward(ch); 
    // From Tilt to Run in the same logical name but in the opposite direction, inertia is expected.
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD_PENDING, relay_chn_get_state(ch));
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FORWARD, relay_chn_get_state(ch));
}

// TEST_CASE 16: Test transition from tilt reverse to run reverse (no inertia expected for run)
// Scenario: RELAY_CHN_STATE_TILT_REVERSE -> (relay_chn_run_reverse) -> RELAY_CHN_STATE_REVERSE
TEST_CASE("Tilt Reverse to Run Reverse transition with inertia", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: Tilt Reverse to Run Reverse transition with inertia");
    uint8_t ch = 0;

    // Prepare channel by running reverse first to set last_run_cmd, then tilt
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_REVERSE);
    relay_chn_tilt_reverse(ch); // Go to tilt state
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_REVERSE, relay_chn_get_state(ch));

    // 2. Issue run reverse command
    relay_chn_run_reverse(ch); 
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE_PENDING, relay_chn_get_state(ch));
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(ch));
}

// TEST_CASE 17: Test transition from tilt forward to run reverse (without inertia)
// Scenario: RELAY_CHN_STATE_TILT_FORWARD -> (relay_chn_run_reverse) -> RELAY_CHN_STATE_REVERSE
TEST_CASE("Tilt Forward to Run Reverse transition without inertia", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: Tilt Forward to Run Reverse transition without inertia");
    uint8_t ch = 0;

    // Prepare channel by running forward first to set last_run_cmd, then tilt
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_FORWARD);
    relay_chn_tilt_forward(ch); // Go to tilt state
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_FORWARD, relay_chn_get_state(ch));

    // 2. Issue run reverse command (opposite direction)
    relay_chn_run_reverse(ch); 
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_REVERSE, relay_chn_get_state(ch));
}

// TEST_CASE 18: Test stopping from a tilt state (no inertia for stop command itself)
// Scenario: RELAY_CHN_STATE_TILT_FORWARD -> (relay_chn_stop) -> RELAY_CHN_STATE_STOPPED -> (inertia) -> RELAY_CHN_STATE_FREE
TEST_CASE("Tilt to Stop transition without immediate inertia for stop", "[relay_chn][tilt][inertia]") {
    ESP_LOGI("TEST", "Running test: Tilt to Stop transition without immediate inertia for stop");
    uint8_t ch = 0;

    // Prepare channel by running forward first to set last_run_cmd, then tilt
    prepare_channel_for_tilt(ch, RELAY_CHN_CMD_FORWARD);
    relay_chn_tilt_forward(ch); // Go to tilt state
    vTaskDelay(pdMS_TO_TICKS(opposite_inertia_ms + test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_TILT_FORWARD, relay_chn_get_state(ch));

    // 2. Issue stop command
    relay_chn_stop(ch);
    // Stop command should apply immediately, setting state to FREE since last state was tilt.
    vTaskDelay(pdMS_TO_TICKS(test_delay_margin_ms));
    TEST_ASSERT_EQUAL(RELAY_CHN_STATE_FREE, relay_chn_get_state(ch));
}

#else // CONFIG_RELAY_CHN_ENABLE_TILTING == 0
// If tilt functionality is disabled, these tests are skipped.
// A dummy test case is added to indicate this in the test output.
TEST_CASE("Tilt functionality is disabled, skipping tilt tests", "[relay_chn][tilt_disabled]") {
    ESP_LOGI("TEST", "Tilt functionality is disabled (CONFIG_RELAY_CHN_ENABLE_TILTING is 0). Skipping tilt tests.");
    TEST_ASSERT_TRUE(true); // Just to ensure at least one test passes for visibility
}
#endif // CONFIG_RELAY_CHN_ENABLE_TILTING


// ### `app_main` Function

// --- app_main function ---
void app_main(void) {
    ESP_LOGI("APP_MAIN", "Starting relay_chn unit tests...");

    // Run the Unity test runner
    unity_run_all_tests();

    // After tests complete, instead of restarting, the device will halt.
    ESP_LOGI("APP_MAIN", "All relay_chn tests completed. Device halted.");
    while (1) {
        vTaskDelay(pdMS_TO_TICKS(1000)); // Wait with low power consumption
    }
}