Add test driver for JSONTestSuite

Makefile.am

@@ -33,7 +33,7 @@ gen: lib/univalue_escapes.h $(GENBIN)
 	@echo Updating $<
 	$(AM_V_at)$(GENBIN) > lib/univalue_escapes.h
 
-noinst_PROGRAMS = $(TESTS)
+noinst_PROGRAMS = $(TESTS) test/test_json
 
 TEST_DATA_DIR=test
 
@@ -42,6 +42,11 @@ test_unitester_LDADD = libunivalue.la
 test_unitester_CXXFLAGS = -I$(top_srcdir)/include -DJSON_TEST_SRC=\"$(srcdir)/$(TEST_DATA_DIR)\"
 test_unitester_LDFLAGS = -static $(LIBTOOL_APP_LDFLAGS)
 
+test_test_json_SOURCES = test/test_json.cpp
+test_test_json_LDADD = libunivalue.la
+test_test_json_CXXFLAGS = -I$(top_srcdir)/include
+test_test_json_LDFLAGS = -static $(LIBTOOL_APP_LDFLAGS)
+
 TEST_FILES = \
 	$(TEST_DATA_DIR)/fail10.json \
 	$(TEST_DATA_DIR)/fail11.json \

test/.gitignore

@@ -1,4 +1,5 @@
 unitester
+test_json
 
 *.trs
 *.log

test/test_json.cpp

@@ -0,0 +1,24 @@
+// Test program that can be called by the JSON test suite at
+// https://github.com/nst/JSONTestSuite.
+//
+// It reads JSON input from stdin and exits with code 0 if it can be parsed
+// successfully. It also pretty prints the parsed JSON value to stdout.
+
+#include <iostream>
+#include <string>
+#include "univalue.h"
+
+using namespace std;
+
+int main (int argc, char *argv[])
+{
+    UniValue val;
+    if (val.read(string(istreambuf_iterator<char>(cin),
+                        istreambuf_iterator<char>()))) {
+        cout << val.write(1 /* prettyIndent */, 4 /* indentLevel */) << endl;
+        return 0;
+    } else {
+        cerr << "JSON Parse Error." << endl;
+        return 1;
+    }
+}