Implement basic transformer tests (#689)

unittests/util/StringUtils.cpp

@@ -0,0 +1,52 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2023, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <util/StringUtils.h>
+
+#include <rpc/RPCHelpers.h>
+
+std::string
+hexStringToBinaryString(std::string const& hex)
+{
+    auto const blob = ripple::strUnHex(hex);
+    std::string strBlob;
+
+    for (auto c : *blob)
+        strBlob += c;
+
+    return strBlob;
+}
+
+ripple::uint256
+binaryStringToUint256(std::string const& bin)
+{
+    ripple::uint256 uint;
+    return uint.fromVoid((void const*)bin.data());
+}
+
+std::string
+ledgerInfoToBinaryString(ripple::LedgerInfo const& info)
+{
+    auto const blob = RPC::ledgerInfoToBlob(info, true);
+    std::string strBlob;
+    for (auto c : blob)
+        strBlob += c;
+
+    return strBlob;
+};