test: add null handling tests for dynamic array functions

.clang-format

@@ -6,7 +6,7 @@ UseTab: Never
 
 ColumnLimit: 100
 
-BreakBeforeBraces: Attach
+BreakBeforeBraces: Allman
 
 AllowShortIfStatementsOnASingleLine: false
 AllowShortFunctionsOnASingleLine: None
@@ -19,4 +19,4 @@ SortIncludes: true
 
 IndentCaseLabels: true
 
-AlignEscapedNewlines: Right
+AlignEscapedNewlines: Left

src/dynamic_array.h

@@ -1,12 +1,10 @@
 #ifndef DYNAMIC_ARRAY_H
 #define DYNAMIC_ARRAY_H
 
-#define DYNAMIC_ARRAY_VERSION_MAJOR 0
-#define DYNAMIC_ARRAY_VERSION_MINOR 1
-#define DYNAMIC_ARRAY_VERSION_BUILD 0
-#define DYNAMIC_ARRAY_VERSION                                                                      \
-    ((DYNAMIC_ARRAY_VERSION_MAJOR << 16) | (DYNAMIC_ARRAY_VERSION_MINOR << 8) |                    \
-     DYNAMIC_ARRAY_VERSION_BUILD)
+#define DYNAMIC_ARRAY_VERSION_MAJOR    0
+#define DYNAMIC_ARRAY_VERSION_MINOR    1
+#define DYNAMIC_ARRAY_VERSION_BUILD    0
+#define DYNAMIC_ARRAY_VERSION          ((DYNAMIC_ARRAY_VERSION_MAJOR << 16) | (DYNAMIC_ARRAY_VERSION_MINOR << 8) | DYNAMIC_ARRAY_VERSION_BUILD)
 
 #include <stddef.h>
 #include <stdlib.h>
@@ -14,6 +12,8 @@
 #define DYNAMIC_ARRAY_DEFAULT_ARRAY_SIZE 10
 #define DYNAMIC_ARRAY_CAPACITY_FACTOR 2
 
+
+
 // [ HEADER | ARRAY ELEMENTS ]
 //          ↑
 // THIS IS THE POINTER RETURNED BY ALL MACROS
@@ -22,48 +22,76 @@ typedef struct {
     size_t capacity;
 } ArrayHeader;
 
+
 #define array_create(arr)                                                                          \
     do {                                                                                           \
-        ArrayHeader* header =                                                                      \
-            malloc(sizeof(*arr) * DYNAMIC_ARRAY_DEFAULT_ARRAY_SIZE + sizeof(ArrayHeader));         \
+        ArrayHeader *header = malloc(                                                              \
+            sizeof(*(arr)) * DYNAMIC_ARRAY_DEFAULT_ARRAY_SIZE + sizeof(ArrayHeader)                \
+        );                                                                                         \
+        if (header == NULL) {                                                                      \
+            abort();                                                                               \
+        }                                                                                          \
         header->size = 0;                                                                          \
         header->capacity = DYNAMIC_ARRAY_DEFAULT_ARRAY_SIZE;                                       \
                                                                                                    \
-        arr = (void*)(header + 1);                                                                 \
-    } while (0)
+        (arr) = (void *)(header + 1);                                                              \
+    } while(0)
+
+
+#define array_get_header(arr) \
+    ((arr) ? ((ArrayHeader*)(arr) - 1) : NULL)
 
-#define array_get_header(arr) ((ArrayHeader*)(arr) - 1)
 
 #define array_destroy(arr)                                                                         \
     do {                                                                                           \
+        if ((arr) == NULL) {                                                                       \
+            break;                                                                                 \
+        }                                                                                          \
         free(array_get_header(arr));                                                               \
-        arr = NULL;                                                                                \
+        (arr) = NULL;                                                                              \
     } while (0)
 
+
 #define array_push_value(arr, value)                                                               \
     do {                                                                                           \
-        ArrayHeader* header = array_get_header(arr);                                               \
-        if (header->size + 1 > header->capacity) {                                                 \
-            size_t new_capacity = header->capacity * DYNAMIC_ARRAY_CAPACITY_FACTOR;                \
-            ArrayHeader* new_header =                                                              \
-                realloc(header, sizeof(*arr) * new_capacity + sizeof(ArrayHeader));                \
-            if (new_header != NULL) {                                                              \
-                header = new_header;                                                               \
-            }                                                                                      \
-            header->capacity = new_capacity;                                                       \
-            arr = (void*)(header + 1);                                                             \
+        if ((arr) == NULL) {                                                                       \
+            array_create(arr);                                                                     \
         }                                                                                          \
-        arr[header->size] = value;                                                                 \
+        ArrayHeader *header = array_get_header(arr);                                               \
+        if (header->size >= header->capacity) {                                                    \
+            size_t new_capacity = header->capacity * DYNAMIC_ARRAY_CAPACITY_FACTOR;                \
+            ArrayHeader *new_header = realloc(                                                     \
+                header, sizeof(*(arr)) * new_capacity + sizeof(ArrayHeader)                        \
+            );                                                                                     \
+            if (new_header == NULL) {                                                              \
+                abort();                                                                           \
+            }                                                                                      \
+            header = new_header;                                                                   \
+            header->capacity = new_capacity;                                                       \
+            (arr) = (void *)(header + 1);                                                          \
+        }                                                                                          \
+        (arr)[header->size] = (value);                                                             \
         header->size++;                                                                            \
     } while (0)
 
+
 #define array_pop(arr)                                                                             \
     do {                                                                                           \
-        ArrayHeader* header = array_get_header(arr);                                               \
+        if ((arr) == NULL) {                                                                       \
+            break;                                                                                 \
+        }                                                                                          \
+        ArrayHeader *header = array_get_header(arr);                                               \
         if (header->size == 0) {                                                                   \
             break;                                                                                 \
         }                                                                                          \
         header->size--;                                                                            \
     } while (0)
 
+
+#define array_size(arr) \
+    ((arr) ? array_get_header(arr)->size : 0)
+
+#define array_capacity(arr) \
+    ((arr) ? array_get_header(arr)->capacity : 0)
+
 #endif

src/test_dynamic_array.c

@@ -178,6 +178,74 @@ void test_array_looping(void) {
 }
 
 
+/* --- array_get_header branch: NULL arr → returns NULL --- */
+void test_array_get_header_on_null_returns_null(void) {
+    int *arr = NULL;
+    TEST_ASSERT_NULL(array_get_header(arr));
+}
+
+
+/* --- array_destroy branch: NULL arr → no-op, does not crash --- */
+void test_array_destroy_on_null_is_noop(void) {
+    int *arr = NULL;
+    array_destroy(arr);
+    TEST_ASSERT_NULL(arr);
+}
+
+
+/* --- array_push_value branch: NULL arr → auto-creates the array --- */
+void test_array_push_value_on_null_auto_creates(void) {
+    int *arr = NULL;
+    array_push_value(arr, 7);
+    TEST_ASSERT_NOT_NULL(arr);
+    TEST_ASSERT_EQUAL(7, arr[0]);
+    TEST_ASSERT_EQUAL(1, array_get_header(arr)->size);
+    array_destroy(arr);
+}
+
+
+/* --- array_pop branch: NULL arr → no-op, does not crash --- */
+void test_array_pop_on_null_is_noop(void) {
+    int *arr = NULL;
+    array_pop(arr);
+    TEST_ASSERT_NULL(arr);
+}
+
+
+/* --- array_size branch: NULL arr → 0 --- */
+void test_array_size_on_null_returns_zero(void) {
+    int *arr = NULL;
+    TEST_ASSERT_EQUAL(0, array_size(arr));
+}
+
+
+/* --- array_size branch: non-NULL arr → current size --- */
+void test_array_size_returns_current_size(void) {
+    int *arr = NULL;
+    array_create(arr);
+    array_push_value(arr, 1);
+    array_push_value(arr, 2);
+    TEST_ASSERT_EQUAL(2, array_size(arr));
+    array_destroy(arr);
+}
+
+
+/* --- array_capacity branch: NULL arr → 0 --- */
+void test_array_capacity_on_null_returns_zero(void) {
+    int *arr = NULL;
+    TEST_ASSERT_EQUAL(0, array_capacity(arr));
+}
+
+
+/* --- array_capacity branch: non-NULL arr → current capacity --- */
+void test_array_capacity_returns_current_capacity(void) {
+    int *arr = NULL;
+    array_create(arr);
+    TEST_ASSERT_EQUAL(DYNAMIC_ARRAY_DEFAULT_ARRAY_SIZE, array_capacity(arr));
+    array_destroy(arr);
+}
+
+
 int main(void)
 {
     UNITY_BEGIN();
@@ -195,5 +263,14 @@ int main(void)
     RUN_TEST(test_array_values_correct_after_growth);
     RUN_TEST(test_array_looping);
 
+    RUN_TEST(test_array_get_header_on_null_returns_null);
+    RUN_TEST(test_array_destroy_on_null_is_noop);
+    RUN_TEST(test_array_push_value_on_null_auto_creates);
+    RUN_TEST(test_array_pop_on_null_is_noop);
+    RUN_TEST(test_array_size_on_null_returns_zero);
+    RUN_TEST(test_array_size_returns_current_size);
+    RUN_TEST(test_array_capacity_on_null_returns_zero);
+    RUN_TEST(test_array_capacity_returns_current_capacity);
+
     return UNITY_END();
 }