testing: refactoring; fixes file_download

test/test_utils/test_utils.h

@@ -0,0 +1,21 @@
+#ifndef TEST_UTILS_H
+#define TEST_UTILS_H
+
+#include <main.h>
+#include <stdio.h>
+#include <utils.h>
+
+typedef struct {
+  char *ptr;
+  size_t len;
+  size_t capacity;
+} dbuf_t;
+
+void fill_list_with_samples(fl_t *fl_samples, fl_t **fl_st, fl_t **fl_cur,
+                            int amount);
+dbuf_t *dbuf_init(size_t init_sz);
+int32_t dbuf_write(const char *text, size_t len, dbuf_t **dbuf);
+int32_t dbuf_destroy(dbuf_t **dbuf);
+int __wrap_print_log(FILE *output, enum pl_type type, const char *fmt, ...);
+
+#endif