add splitter tests

test/test_helpers.hpp

@@ -0,0 +1,22 @@
+#pragma once
+#include <cstring>
+
+#ifdef CMAKE_GITHUB_CI
+#include <doctest/doctest.h>
+#else
+#include <doctest.h>
+#endif
+
+class buffer {
+    constexpr static auto buff_size = 1024;
+    char data_[buff_size];
+
+public:
+    char* operator()(const char* data) {
+        memset(data_, '\0', buff_size);
+        strcpy(data_, data);
+        return data_;
+    }
+};
+
+[[maybe_unused]] inline buffer buff;