t/: port helper/test-strcmp-offset.c to unit-tests/t-strcmp-offset.c

In the recent codebase update (8bf6fbd (Merge branch
'js/doc-unit-tests', 2023-12-09)), a new unit testing framework was
merged, providing a standardized approach for testing C code. Prior to
this update, some unit tests relied on the test helper mechanism,
lacking a dedicated unit testing framework. It's more natural to perform
these unit tests using the new unit test framework.

Let's migrate the unit tests for strcmp-offset functionality from the
legacy approach using the test-tool command `test-tool strcmp-offset` in
helper/test-strcmp-offset.c to the new unit testing framework
(t/unit-tests/test-lib.h).

The migration involves refactoring the tests to utilize the testing
macros provided by the framework (TEST() and check_*()).

Helped-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Co-authored-by: Achu Luma <ach.lumap@gmail.com>
Signed-off-by: Achu Luma <ach.lumap@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/t/unit-tests/t-strcmp-offset.c b/t/unit-tests/t-strcmp-offset.c
new file mode 100644
index 0000000000..fe4c2706b1
--- /dev/null
+++ b/t/unit-tests/t-strcmp-offset.c
@@ -0,0 +1,35 @@
+#include "test-lib.h"
+#include "read-cache-ll.h"
+
+static void check_strcmp_offset(const char *string1, const char *string2,
+				int expect_result, uintmax_t expect_offset)
+{
+	size_t offset;
+	int result = strcmp_offset(string1, string2, &offset);
+
+	/*
+	 * Because different CRTs behave differently, only rely on signs of the
+	 * result values.
+	 */
+	result = (result < 0 ? -1 :
+			result > 0 ? 1 :
+			0);
+
+	check_int(result, ==, expect_result);
+	check_uint((uintmax_t)offset, ==, expect_offset);
+}
+
+#define TEST_STRCMP_OFFSET(string1, string2, expect_result, expect_offset) \
+	TEST(check_strcmp_offset(string1, string2, expect_result,          \
+				 expect_offset),                           \
+	     "strcmp_offset(%s, %s) works", #string1, #string2)
+
+int cmd_main(int argc, const char **argv)
+{
+	TEST_STRCMP_OFFSET("abc", "abc", 0, 3);
+	TEST_STRCMP_OFFSET("abc", "def", -1, 0);
+	TEST_STRCMP_OFFSET("abc", "abz", -1, 2);
+	TEST_STRCMP_OFFSET("abc", "abcdef", -1, 3);
+
+	return test_done();
+}