Implement valid_json?

Author: jhawthorn

ext/rapidjson/cext.cc

@@ -40,6 +40,20 @@ VALUE parse(VALUE _self, VALUE string) {
     return handler.GetRoot();
 }
 
+VALUE valid_json_p(VALUE _self, VALUE string) {
+    NullHandler handler;
+    Reader reader;
+    char *cstring = StringValueCStr(string); // fixme?
+    StringStream ss(cstring);
+    ParseResult ok = reader.Parse(ss, handler);
+
+    if (!ok) {
+        return Qfalse;
+    }
+
+    return Qtrue;
+}
+
 extern "C" void
 Init_rapidjson(void)
 {
@@ -50,6 +64,7 @@ Init_rapidjson(void)
 
     rb_define_module_function(rb_mRapidjson, "parse", parse, 1);
     rb_define_module_function(rb_mRapidjson, "load", parse, 1);
+    rb_define_module_function(rb_mRapidjson, "valid_json?", valid_json_p, 1);
 
     rb_eParseError = rb_define_class_under(rb_mRapidjson, "ParseError", rb_eStandardError);
     rb_eEncodeError = rb_define_class_under(rb_mRapidjson, "EncodeError", rb_eStandardError);

ext/rapidjson/parser.hh

@@ -4,6 +4,9 @@
 
 using namespace rapidjson;
 
+class NullHandler : public BaseReaderHandler<UTF8<>, NullHandler> {
+};
+
 struct RubyObjectHandler : public BaseReaderHandler<UTF8<>, RubyObjectHandler> {
     bool Null() {
         return PutValue(Qnil);

test/test_jsonchecker.rb

@@ -12,12 +12,14 @@ class TestJsonchecker < Minitest::Test
     define_method(:"test_#{name}") do
       original_json = File.read(filename)
       if name.start_with?("fail") && !exclude
+        refute RapidJSON.valid_json?(original_json)
         ex = assert_raises RapidJSON::ParseError do
           RapidJSON.parse(original_json)
         end
         re = /JSON parse error: .* \(\d+\)\z/
         assert_match re, ex.message
       else
+        assert RapidJSON.valid_json?(original_json)
         assert RapidJSON.parse(original_json)
       end
     end