[PATCH v3 3/4] mergesort: cover empty and small lists
- From
- Muhammed Dilshad A <dilsheddilu123@gmail.com>
- Date
- Oct 9, 2026, 15:08 UTC
- Message-ID
- <da42c96904489fcd37506916d5aac5be197df382.1791556668.git.dilsheddilu123@gmail.com>
- In-Reply-To
- <cover.1791556668.git.dilsheddilu123@gmail.com>
The existing tests use at least 100 items. Add empty and single-item lists, reversed and equal pairs, and a small list with duplicate values and integer limits. Add two sorted runs whose values need to interleave during the merge.
Also check that the debug version sorts a two-item list and calls both the get-next and set-next hooks.
Signed-off-by: Muhammed Dilshad A <dilsheddilu123@gmail.com> --- t/unit-tests/u-mergesort.c | 63 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+)
diff --git a/t/unit-tests/u-mergesort.c b/t/unit-tests/u-mergesort.c index 50bca1db46..1a5c0a60a8 100644 --- a/t/unit-tests/u-mergesort.c +++ b/t/unit-tests/u-mergesort.c @@ -9,6 +9,11 @@ struct number { DEFINE_LIST_SORT(static, sort_numbers, struct number, next); +static int get_next_count, set_next_count; + +DEFINE_LIST_SORT_DEBUG(static, sort_numbers_debug, struct number, next, + get_next_count++, set_next_count++); + static int compare_numbers(const struct number *a, const struct number *b) { return (a->value > b->value) - (a->value < b->value); @@ -103,3 +108,61 @@ void test_mergesort__random(void) for (size_t i = 0; i < ARRAY_SIZE(sizes); i++) check_sort(input, sizes[i]); } + +void test_mergesort__empty(void) +{ + check_sort(NULL, 0); +} + +void test_mergesort__singleton(void) +{ + const int input[] = { 42 }; + + check_sort(input, ARRAY_SIZE(input)); +} + +void test_mergesort__reversed_pair(void) +{ + const int input[] = { 2, 1 }; + + check_sort(input, ARRAY_SIZE(input)); +} + +void test_mergesort__equal_pair(void) +{ + const int input[] = { 1, 1 }; + + check_sort(input, ARRAY_SIZE(input)); +} + +void test_mergesort__interleaved_runs(void) +{ + const int input[] = { 0, 2, 4, 6, 1, 3, 5, 7 }; + + check_sort(input, ARRAY_SIZE(input)); +} + +void test_mergesort__mixed_values(void) +{ + const int input[] = { INT_MAX, -1, 0, INT_MIN, -1, INT_MAX, 0 }; + + check_sort(input, ARRAY_SIZE(input)); +} + +void test_mergesort__debug_hooks(void) +{ + struct number nodes[] = { + { .value = 2 }, + { .value = 1 }, + }; + struct number *list = &nodes[0]; + + nodes[0].next = &nodes[1]; + get_next_count = set_next_count = 0; + sort_numbers_debug(&list, compare_numbers); + cl_assert_equal_p(list, &nodes[1]); + cl_assert_equal_p(list->next, &nodes[0]); + cl_assert_equal_p(list->next->next, NULL); + cl_assert_gt_i(get_next_count, 0); + cl_assert_gt_i(set_next_count, 0); +}
-- 2.55.0