test: Added further testing and fixed functions for edge cases

test/test_arena.c

@@ -7,6 +7,7 @@
 #include <setjmp.h>
 #include <cmocka.h>
 #include <string.h>
+#include <limits.h>
 
 #include "arena.h"
 
@@ -71,11 +72,49 @@ static void test_push_3_ints_2_doubles(void **state) {
     arena_destroy(&arena);
 }
 
+static void test_init_arena_0_cap(void **state) {
+    (void) state;
+
+    ArenaResult arena = arena_init(0);
+    assert_false(arena.is_valid);
+    assert_int_equal(arena.err, ARENA_INVALID_SIZE);
+}
+
+static void test_arena_alloc_size_0(void **state) {
+    (void) state;
+
+    ArenaResult value = arena_init(64);
+    assert_true(value.is_valid);
+    Arena arena = value.arena;
+
+    ArenaPointer pointer = arena_alloc(&arena, 0, alignof(int));
+    assert_false(pointer.is_valid);
+    assert_int_equal(pointer.err, ARENA_INVALID_SIZE);
+
+    arena_destroy(&arena);
+}
+
+static void test_arena_alloc_size_max(void **state) {
+    (void) state;
+
+    ArenaResult value = arena_init(64);
+    assert_true(value.is_valid);
+    Arena arena = value.arena;
+
+    ArenaPointer pointer = arena_alloc(&arena, SIZE_MAX, alignof(int));
+    assert_false(pointer.is_valid);
+    assert_int_equal(pointer.err, ARENA_OUT_OF_SPACE);
+
+    arena_destroy(&arena);
+}
 
 int main(void) {
     const struct CMUnitTest tests[] = {
         cmocka_unit_test(test_push_3_ints),
         cmocka_unit_test(test_push_3_ints_2_doubles),
+        cmocka_unit_test(test_init_arena_0_cap),
+        cmocka_unit_test(test_arena_alloc_size_0),
+        cmocka_unit_test(test_arena_alloc_size_max),
     };