Refactoring: move declarations to rest.h

This facilitates unit testing

src/Makefile.am

@@ -198,6 +198,7 @@ BITCOIN_CORE_H = \
   psbt.h \
   random.h \
   randomenv.h \
+  rest.h \
   reverse_iterator.h \
   rpc/blockchain.h \
   rpc/client.h \

src/rest.cpp

@@ -3,6 +3,8 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <rest.h>
+
 #include <blockfilter.h>
 #include <chain.h>
 #include <chainparams.h>
@@ -27,6 +29,7 @@
 #include <version.h>
 
 #include <any>
+#include <string>
 
 #include <boost/algorithm/string.hpp>
 
@@ -40,13 +43,6 @@ using node::ReadBlockFromDisk;
 static const size_t MAX_GETUTXOS_OUTPOINTS = 15; //allow a max of 15 outpoints to be queried at once
 static constexpr unsigned int MAX_REST_HEADERS_RESULTS = 2000;
 
-enum class RetFormat {
-    UNDEF,
-    BINARY,
-    HEX,
-    JSON,
-};
-
 static const struct {
     RetFormat rf;
     const char* name;
@@ -137,7 +133,7 @@ static ChainstateManager* GetChainman(const std::any& context, HTTPRequest* req)
     return node_context->chainman.get();
 }
 
-static RetFormat ParseDataFormat(std::string& param, const std::string& strReq)
+RetFormat ParseDataFormat(std::string& param, const std::string& strReq)
 {
     const std::string::size_type pos = strReq.rfind('.');
     if (pos == std::string::npos)

src/rest.h

@@ -0,0 +1,19 @@
+// Copyright (c) 2015-2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_REST_H
+#define BITCOIN_REST_H
+
+#include <string>
+
+enum class RetFormat {
+    UNDEF,
+    BINARY,
+    HEX,
+    JSON,
+};
+
+RetFormat ParseDataFormat(std::string& param, const std::string& strReq);
+
+#endif // BITCOIN_REST_H