Re: [PATCH 1/5] t/unit-tests: implement oid helper functions in unit-tests.{c,h}

> `get_oid_arbitrary_hex()` and `init_hash_algo()` are both required for
> oid-related tests to run without errors. In the current implementation,
> both functions are defined and declared in the
> `t/unit-tests/lib-oid.{c,h}` which is utilized by oid-related tests in
> the homegrown unit tests structure.
> 
> Implement equivalent functions in unit-tests.{c,h}. Both these functions
> become available for oid-related test files implemented using the clar
> testing framework, which requires them. This will be used by subsequent
> commits.

> Mentored-by: Patrick Steinhardt <ps@pks.im>
> Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
> ---
>   t/unit-tests/unit-test.c | 42 ++++++++++++++++++++++++++++++++++++++++
>   t/unit-tests/unit-test.h | 19 ++++++++++++++++++
>   2 files changed, 61 insertions(+)
> 
> diff --git a/t/unit-tests/unit-test.c b/t/unit-tests/unit-test.c
> index fa8818842a..13d54f192a 100644
> --- a/t/unit-tests/unit-test.c
> +++ b/t/unit-tests/unit-test.c
> @@ -1,5 +1,7 @@
>   #include "unit-test.h"
> +#include "hex.h"
>   #include "parse-options.h"
> +#include "strbuf.h"
>   #include "string-list.h"
>   #include "strvec.h"
>   
> @@ -62,3 +64,43 @@ int cmd_main(int argc, const char **argv)
>   	strvec_clear(&args);
>   	return ret;
>   }
> +
> +int init_hash_algo(void)
> +{
> +	static int algo = -1;
> +
> +	if (algo < 0) {
> +		const char *algo_name = getenv("GIT_TEST_DEFAULT_HASH");
> +		algo = algo_name ? hash_algo_by_name(algo_name) : GIT_HASH_SHA1;
> +
> +		cl_assert(algo != GIT_HASH_UNKNOWN);
> +	}
> +	return algo;
> +}
> +
> +static void cl_parse_oid(const char *hex, struct object_id *oid,
> +				       const struct git_hash_algo *algop)
> +{
> +	int ret;
> +	size_t sz = strlen(hex);
> +	struct strbuf buf = STRBUF_INIT;
> +
> +	cl_assert(sz <= algop->hexsz);
> +
> +	strbuf_add(&buf, hex, sz);
> +	strbuf_addchars(&buf, '0', algop->hexsz - sz);
> +
> +	ret = get_oid_hex_algop(buf.buf, oid, algop);
> +	cl_assert_equal_i(ret, 0);
> +
> +	strbuf_release(&buf);
> +}
> +
> +
> +void cl_parse_any_oid(const char *hex, struct object_id *oid)
> +{
> +	int hash_algo = init_hash_algo();
> +
> +	cl_assert(hash_algo != GIT_HASH_UNKNOWN);
> +	cl_parse_oid(hex, oid, &hash_algos[hash_algo]);
> +}
> diff --git a/t/unit-tests/unit-test.h b/t/unit-tests/unit-test.h
> index 85e5d6a948..ebed51212f 100644
> --- a/t/unit-tests/unit-test.h
> +++ b/t/unit-tests/unit-test.h
> @@ -8,3 +8,22 @@
>   	snprintf(desc, sizeof(desc), fmt, __VA_ARGS__); \
>   	clar__fail(__FILE__, __func__, __LINE__, "Test failed.", desc, 1); \
>   } while (0)
> +
> +/*
> + * Convert arbitrary hex string to object_id.
> + * For example, passing "abc12" will generate
> + * "abc1200000000000000000000000000000000000" hex of length 40 for SHA-1 and
> + * create object_id with that.
> + * WARNING: passing a string of length more than the hexsz of respective hash
> + * algo is not allowed. The hash algo is decided based on GIT_TEST_DEFAULT_HASH
> + * environment variable.
> + */
> +void cl_parse_any_oid(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
> + * cl_assert(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);