Hi, Sergey!
Thanks for the patch!
Please consider a few comments below.
> 
>>This header contains generic init and close for tests and helpers for
>>loading auxiliary Lua script with functions to run inside a C test.
>>
>>It will be properly used in the next commit.
>>
>>Part of tarantool/tarantool#7900
>>---
>> test/tarantool-c-tests/utils.h | 63 ++++++++++++++++++++++++++++++++++
>> 1 file changed, 63 insertions(+)
>> create mode 100644 test/tarantool-c-tests/utils.h
>>
>>diff --git a/test/tarantool-c-tests/utils.h b/test/tarantool-c-tests/utils.h
>>new file mode 100644
>>index 00000000..cf668006
>>--- /dev/null
>>+++ b/test/tarantool-c-tests/utils.h
>>@@ -0,0 +1,63 @@
>>+#include <limits.h>
>>+#include <string.h>
>>+
>>+#include "lauxlib.h"
>>+#include "lua.h"
>>+#include "luajit.h"
>>+#include "lualib.h"
>>+
>>+#include "test.h"
>>+
>>+/* Generic init for our tests. */
>>+static lua_State *utils_lua_init(void)
>>+{
>>+ lua_State *L = luaL_newstate();
>>+ if (!L)
>>+ bail_out("Can't init Lua state");
>>+ /* Stop collector during library initialization. */
>>+ lua_gc(L, LUA_GCSTOP, 0);
>>+ luaL_openlibs(L);
>>+ lua_gc(L, LUA_GCRESTART, -1);
>>+ return L;
>>+}
>>+
>>+/* Generic close for our tests. */
>>+static void utils_lua_close(lua_State *L)
>>+{
>>+ lua_close(L);
>>+}
>Do we __really__ need this function?)
>>+
>>+/*
>>+ * Load the pair to the test file <filename-script.lua>.
>>+ * Each file should return the table with functions (named the
>>+ * same as the corresponding unit tests) to call in unit tests.
>>+ * Push the table with those functions on the Lua stack.
>>+ */
>>+#define utils_load_aux_script(L) do { \
>>+ /* \
>>+ * Format script name. \
>>+ * `__ABS_FILENAME__` is set via CMake. \
>>+ */ \
>>+ char script[PATH_MAX] = __ABS_FILENAME__; \
>>+ char *file_suffix = strstr(script, ".test.c"); \
>The `strstr` function is not safe, use `strnstr` instead.
>Also, maybe it is better to use the `strrstr` variation,
>because it searches from the end. It eleminates issues
>in case of a file with .test.c somewhere else in the name.
>>+ strcpy(file_suffix, "-script.lua"); \
>Same applies here.
>>+ \
>>+ if (luaL_dofile((L), script) != LUA_OK) { \
>>+ test_comment("Can't load %s: '%s'", script, \
>>+ lua_tostring((L), -1)); \
>>+ bail_out("Can't load auxiliary script"); \
>>+ } \
>>+ \
>>+ if (!lua_istable((L), -1)) \
>>+ bail_out("Returned value from script is not a table"); \
>>+} while (0)
>>+
>>+/*
>>+ * Accept a table on top of the Lua stack which containing the
>>+ * function named as the unit test we currently executing.
>>+ */
>>+#define utils_get_aux_lfunc(L) do { \
>>+ lua_getfield((L), -1, __func__); \
>>+ if (!lua_isfunction((L), -1)) \
>>+ bail_out("Can't get auxiliary test function"); \
>>+} while (0)
>>--
>>2.34.1
> 
>--
>Best regards,
>Maxim Kokryashkin
>