t: port helper/test-oid-array.c to unit-tests/t-oid-array.c

helper/test-oid-array.c along with t0064-oid-array.sh test the
oid-array.h API, which provides storage and processing
efficiency over large lists of object identifiers.

Migrate them to the unit testing framework for better runtime
performance and efficiency. As we don't initialize a repository
in these tests, the hash algo that functions like oid_array_lookup()
use is not initialized, therefore call repo_set_hash_algo() to
initialize it. And init_hash_algo():lib-oid.c can aid in this
process, so make it public.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/t/unit-tests/lib-oid.h b/t/unit-tests/lib-oid.h
index 8d2acca768..4e77c04bd2 100644
--- a/t/unit-tests/lib-oid.h
+++ b/t/unit-tests/lib-oid.h
@@ -13,5 +13,13 @@
  * environment variable.
  */
 int get_oid_arbitrary_hex(const char *s, struct object_id *oid);
+/*
+ * Returns one of GIT_HASH_{SHA1, SHA256, UNKNOWN} based on the value of
+ * GIT_TEST_DEFAULT_HASH environment variable. The fallback value in the
+ * absence of GIT_TEST_DEFAULT_HASH is GIT_HASH_SHA1. It also uses
+ * check(algo != GIT_HASH_UNKNOWN) before returning to verify if the
+ * GIT_TEST_DEFAULT_HASH's value is valid or not.
+ */
+int init_hash_algo(void);
 
 #endif /* LIB_OID_H */