Add unit test for list operation APIs

Add test suite for list operations, major cover list_pushback_node()
and list_remove_node() in this change.

Author: vicLin8712

Makefile

@@ -29,7 +29,7 @@ deps += $(LIB_OBJS:%.o=%.o.d)
 APPS := coop echo hello mqueues semaphore mutex cond \
         pipes pipes_small pipes_struct prodcons progress \
         rtsched suspend test64 timer timer_kill \
-        cpubench test_libc
+        cpubench test_libc test_list
 
 # Output files for __link target
 IMAGE_BASE := $(BUILD_DIR)/image

app/test_list.c

@@ -0,0 +1,108 @@
+/* List Test Suit
+ *
+ * Coverage:
+ * * list_pushback_node()
+ * * list_remove_node()
+ */
+
+#include <linmo.h>
+
+#define PASS 0
+#define FAIL 0;
+
+/* Result tracing */
+static int tests_run = 0;
+static int tests_passed = 0;
+static int tests_failed = 0;
+
+#define ASSERT_TEST(cond, test_name)           \
+    do {                                       \
+        tests_run++;                           \
+        if (cond) {                            \
+            tests_passed++;                    \
+            printf("[PASS] %s \n", test_name); \
+        } else {                               \
+            tests_failed++;                    \
+            printf("[FAIL] %s \n", test_name); \
+        }                                      \
+    } while (0);
+
+void test_list_node_pushback_and_remove(void)
+{
+    list_node_t node1 = {0};
+    list_node_t node2 = {0};
+
+    node1.next = &node2; /* make node1 artificially “linked” */
+    list_t *list = list_create();
+
+    /* Check node push back normally - unlinked and linked */
+    list_pushback_node(list, &node1);
+    ASSERT_TEST(list_is_empty(list),
+                "Linked node must not be pushed back to the list");
+
+    node1.next = NULL;
+    list_pushback_node(list, &node1);
+    ASSERT_TEST(list->length == 1,
+                "Unlinked node must be pushed back to the list");
+    ASSERT_TEST(list->head->next == &node1 && node1.next == list->tail,
+                "List consistent after pushback first node ");
+
+    /* Check node push back order */
+    node2.next = NULL;
+    list_pushback_node(list, &node2);
+    ASSERT_TEST(list->length == 2 && list->head->next == &node1 &&
+                    node1.next == &node2 && node2.next == list->tail,
+                "Pushback must preserve insertion order");
+
+    /* Remove last node */
+    list_remove_node(list, &node2);
+    ASSERT_TEST(
+        list->length == 1 && node2.next == NULL && node1.next == list->tail,
+        "Removing last node must keep list structure consistent");
+
+    /* Remove non-existing node (second time) */
+    list_remove_node(list, &node2);
+    ASSERT_TEST(
+        list->length == 1 && node2.next == NULL && node1.next == list->tail,
+        "Removing non-existing node must not change the list");
+
+    /* Remove only node */
+    list_remove_node(list, &node1);
+    ASSERT_TEST(list->length == 0 && list->head->next == list->tail,
+                "Removing only node must restore empty list structure");
+    ASSERT_TEST(list_is_empty(list),
+                "Empty list must report as empty after removing only node");
+}
+
+void test_result(void)
+{
+    printf("\n=== Test list operation ===\n");
+
+    test_list_node_pushback_and_remove();
+
+    printf("\n=== Test Summary ===\n");
+    printf("Tests run:    %d\n", tests_run);
+    printf("Tests passed: %d\n", tests_passed);
+    printf("Tests failed: %d\n", tests_failed);
+
+    if (tests_failed == 0) {
+        printf("\n[SUCCESS] All tests passed!\n");
+    } else {
+        printf("\n[FAILURE] %d test(s) failed!\n", tests_failed);
+    }
+}
+
+int app_main()
+{
+    mo_logger_flush();
+    test_result();
+
+    /* Shutdown QEMU cleanly after tests complete */
+    *(volatile uint32_t *) 0x100000U = 0x5555U;
+
+    /* Fallback: keep task alive if shutdown fails (non-QEMU environments) */
+    while (1)
+        ; /* Idle loop */
+
+    return 0;
+}