* ext/json/*, test/json/*: Update json-2.0.1.

  Changes of 2.0.0: https://github.com/flori/json/blob/f679ebd0c69a94e3e70a897ac9a229f5779c2ee1/CHANGES.md#2015-09-11-200
  Changes of 2.0.1: https://github.com/flori/json/blob/f679ebd0c69a94e3e70a897ac9a229f5779c2ee1/CHANGES.md#2016-07-01-201
  [Feature #12542][ruby-dev:49706][fix GH-1395]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55576 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

27 files changed, 1158 insertions, 1497 deletions

diff --git a/ChangeLog b/ChangeLog
index 28598a9567..0edc49ad31 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Jul  5 20:49:30 2016  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
+
+	* ext/json/*, test/json/*: Update json-2.0.1.
+	  Changes of 2.0.0: https://github.com/flori/json/blob/f679ebd0c69a94e3e70a897ac9a229f5779c2ee1/CHANGES.md#2015-09-11-200
+	  Changes of 2.0.1: https://github.com/flori/json/blob/f679ebd0c69a94e3e70a897ac9a229f5779c2ee1/CHANGES.md#2016-07-01-201
+	  [Feature #12542][ruby-dev:49706][fix GH-1395]
+
 Tue Jul  5 19:39:49 2016  Naohisa Goto  <ngotogenome@gmail.com>
 
 	* string.c (rb_str_change_terminator_length): New function to change
diff --git a/ext/json/generator/generator.c b/ext/json/generator/generator.c
index faa4fdf011..2b56721b2d 100644
--- a/ext/json/generator/generator.c
+++ b/ext/json/generator/generator.c
@@ -20,7 +20,7 @@ static VALUE mJSON, mExt, mGenerator, cState, mGeneratorMethods, mObject,
 
 static ID i_to_s, i_to_json, i_new, i_indent, i_space, i_space_before,
           i_object_nl, i_array_nl, i_max_nesting, i_allow_nan, i_ascii_only,
-          i_quirks_mode, i_pack, i_unpack, i_create_id, i_extend, i_key_p,
+          i_pack, i_unpack, i_create_id, i_extend, i_key_p,
           i_aref, i_send, i_respond_to_p, i_match, i_keys, i_depth,
           i_buffer_initial_length, i_dup;
 
@@ -222,6 +222,7 @@ static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string)
             unicode_escape_to_buffer(buffer, buf, (UTF16)((ch & halfMask) + UNI_SUR_LOW_START));
         }
     }
+    RB_GC_GUARD(string);
 }
 
 /* Converts string to a JSON string in FBuffer buffer, where only the
@@ -641,8 +642,6 @@ static VALUE cState_configure(VALUE self, VALUE opts)
     state->allow_nan = RTEST(tmp);
     tmp = rb_hash_aref(opts, ID2SYM(i_ascii_only));
     state->ascii_only = RTEST(tmp);
-    tmp = rb_hash_aref(opts, ID2SYM(i_quirks_mode));
-    state->quirks_mode = RTEST(tmp);
     return self;
 }
 
@@ -676,7 +675,6 @@ static VALUE cState_to_h(VALUE self)
     rb_hash_aset(result, ID2SYM(i_array_nl), rb_str_new(state->array_nl, state->array_nl_len));
     rb_hash_aset(result, ID2SYM(i_allow_nan), state->allow_nan ? Qtrue : Qfalse);
     rb_hash_aset(result, ID2SYM(i_ascii_only), state->ascii_only ? Qtrue : Qfalse);
-    rb_hash_aset(result, ID2SYM(i_quirks_mode), state->quirks_mode ? Qtrue : Qfalse);
     rb_hash_aset(result, ID2SYM(i_max_nesting), LONG2FIX(state->max_nesting));
     rb_hash_aset(result, ID2SYM(i_depth), LONG2FIX(state->depth));
     rb_hash_aset(result, ID2SYM(i_buffer_initial_length), LONG2FIX(state->buffer_initial_length));
@@ -853,7 +851,6 @@ static void generate_json_integer(FBuffer *buffer, VALUE Vstate, JSON_Generator_
         generate_json_bignum(buffer, Vstate, state, obj);
 }
 #endif
-
 static void generate_json_float(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj)
 {
     double value = RFLOAT_VALUE(obj);
@@ -944,21 +941,6 @@ static VALUE cState_partial_generate(VALUE self, VALUE obj)
 }
 
 /*
- * This function returns true if string is either a JSON array or JSON object.
- * It might suffer from false positives, e. g. syntactically incorrect JSON in
- * the string or certain UTF-8 characters on the right hand side.
- */
-static int isArrayOrObject(VALUE string)
-{
-    long string_len = RSTRING_LEN(string);
-    char *p = RSTRING_PTR(string), *q = p + string_len - 1;
-    if (string_len < 2) return 0;
-    for (; p < q && isspace((unsigned char)*p); p++);
-    for (; q > p && isspace((unsigned char)*q); q--);
-    return (*p == '[' && *q == ']') || (*p == '{' && *q == '}');
-}
-
-/*
  * call-seq: generate(obj)
  *
  * Generates a valid JSON document from object +obj+ and returns the
@@ -969,9 +951,6 @@ static VALUE cState_generate(VALUE self, VALUE obj)
 {
     VALUE result = cState_partial_generate(self, obj);
     GET_STATE(self);
-    if (!state->quirks_mode && !isArrayOrObject(result)) {
-        rb_raise(eGeneratorError, "only generation of JSON objects or arrays allowed");
-    }
     return result;
 }
 
@@ -990,8 +969,6 @@ static VALUE cState_generate(VALUE self, VALUE obj)
  * * *allow_nan*: true if NaN, Infinity, and -Infinity should be
  *   generated, otherwise an exception is thrown, if these values are
  *   encountered. This options defaults to false.
- * * *quirks_mode*: Enables quirks_mode for parser, that is for example
- *   generating single JSON values instead of documents is possible.
  * * *buffer_initial_length*: sets the initial length of the generator's
  *   internal buffer.
  */
@@ -1299,29 +1276,6 @@ static VALUE cState_ascii_only_p(VALUE self)
 }
 
 /*
- * call-seq: quirks_mode?
- *
- * Returns true, if quirks mode is enabled. Otherwise returns false.
- */
-static VALUE cState_quirks_mode_p(VALUE self)
-{
-    GET_STATE(self);
-    return state->quirks_mode ? Qtrue : Qfalse;
-}
-
-/*
- * call-seq: quirks_mode=(enable)
- *
- * If set to true, enables the quirks_mode mode.
- */
-static VALUE cState_quirks_mode_set(VALUE self, VALUE enable)
-{
-    GET_STATE(self);
-    state->quirks_mode = RTEST(enable);
-    return Qnil;
-}
-
-/*
  * call-seq: depth
  *
  * This integer returns the current depth of data structure nesting.
@@ -1409,9 +1363,6 @@ void Init_generator(void)
     rb_define_method(cState, "check_circular?", cState_check_circular_p, 0);
     rb_define_method(cState, "allow_nan?", cState_allow_nan_p, 0);
     rb_define_method(cState, "ascii_only?", cState_ascii_only_p, 0);
-    rb_define_method(cState, "quirks_mode?", cState_quirks_mode_p, 0);
-    rb_define_method(cState, "quirks_mode", cState_quirks_mode_p, 0);
-    rb_define_method(cState, "quirks_mode=", cState_quirks_mode_set, 1);
     rb_define_method(cState, "depth", cState_depth, 0);
     rb_define_method(cState, "depth=", cState_depth_set, 1);
     rb_define_method(cState, "buffer_initial_length", cState_buffer_initial_length, 0);
@@ -1468,7 +1419,6 @@ void Init_generator(void)
     i_max_nesting = rb_intern("max_nesting");
     i_allow_nan = rb_intern("allow_nan");
     i_ascii_only = rb_intern("ascii_only");
-    i_quirks_mode = rb_intern("quirks_mode");
     i_depth = rb_intern("depth");
     i_buffer_initial_length = rb_intern("buffer_initial_length");
     i_pack = rb_intern("pack");
diff --git a/ext/json/generator/generator.h b/ext/json/generator/generator.h
index eb4557ff55..900b4d58f3 100644
--- a/ext/json/generator/generator.h
+++ b/ext/json/generator/generator.h
@@ -73,7 +73,6 @@ typedef struct JSON_Generator_StateStruct {
     long max_nesting;
     char allow_nan;
     char ascii_only;
-    char quirks_mode;
     long depth;
     long buffer_initial_length;
 } JSON_Generator_State;
diff --git a/ext/json/json.gemspec b/ext/json/json.gemspec
index 9fb6fa155a..c5a3c1003d 100644
--- a/ext/json/json.gemspec
+++ b/ext/json/json.gemspec
diff --git a/ext/json/lib/json/common.rb b/ext/json/lib/json/common.rb
index 020615fc1d..a0221fe94b 100644
--- a/ext/json/lib/json/common.rb
+++ b/ext/json/lib/json/common.rb
@@ -4,12 +4,12 @@ require 'json/generic_object'
 
 module JSON
   class << self
-    # If _object_ is string-like, parse the string and return the parsed result
-    # as a Ruby data structure. Otherwise generate a JSON text from the Ruby
-    # data structure object and return it.
+    # If _object_ is string-like, parse the string and return the parsed
+    # result as a Ruby data structure. Otherwise generate a JSON text from the
+    # Ruby data structure object and return it.
     #
-    # The _opts_ argument is passed through to generate/parse respectively. See
-    # generate and parse for their documentation.
+    # The _opts_ argument is passed through to generate/parse respectively.
+    # See generate and parse for their documentation.
     def [](object, opts = {})
       if object.respond_to? :to_str
         JSON.parse(object.to_str, opts)
@@ -25,7 +25,7 @@ module JSON
     # Set the JSON parser class _parser_ to be used by JSON.
     def parser=(parser) # :nodoc:
       @parser = parser
-      remove_const :Parser if JSON.const_defined_in?(self, :Parser)
+      remove_const :Parser if const_defined?(:Parser, false)
       const_set :Parser, parser
     end
 
@@ -36,8 +36,8 @@ module JSON
     def deep_const_get(path) # :nodoc:
       path.to_s.split(/::/).inject(Object) do |p, c|
         case
-        when c.empty?                     then p
-        when JSON.const_defined_in?(p, c) then p.const_get(c)
+        when c.empty?                  then p
+        when p.const_defined?(c, true) then p.const_get(c)
         else
           begin
             p.const_missing(c)
@@ -139,10 +139,10 @@ module JSON
   # _opts_ can have the following
   # keys:
   # * *max_nesting*: The maximum depth of nesting allowed in the parsed data
-  #   structures. Disable depth checking with :max_nesting => false. It defaults
-  #   to 100.
+  #   structures. Disable depth checking with :max_nesting => false. It
+  #   defaults to 100.
   # * *allow_nan*: If set to true, allow NaN, Infinity and -Infinity in
-  #   defiance of RFC 4627 to be parsed by the Parser. This option defaults
+  #   defiance of RFC 7159 to be parsed by the Parser. This option defaults
   #   to false.
   # * *symbolize_names*: If set to true, returns symbols for the names
   #   (keys) in a JSON object. Otherwise strings are returned. Strings are
@@ -162,11 +162,11 @@ module JSON
   #
   # _opts_ can have the following keys:
   # * *max_nesting*: The maximum depth of nesting allowed in the parsed data
-  #   structures. Enable depth checking with :max_nesting => anInteger. The parse!
-  #   methods defaults to not doing max depth checking: This can be dangerous
-  #   if someone wants to fill up your stack.
+  #   structures. Enable depth checking with :max_nesting => anInteger. The
+  #   parse! methods defaults to not doing max depth checking: This can be
+  #   dangerous if someone wants to fill up your stack.
   # * *allow_nan*: If set to true, allow NaN, Infinity, and -Infinity in
-  #   defiance of RFC 4627 to be parsed by the Parser. This option defaults
+  #   defiance of RFC 7159 to be parsed by the Parser. This option defaults
   #   to true.
   # * *create_additions*: If set to false, the Parser doesn't create
   #   additions even if a matching class and create_id was found. This option
@@ -175,7 +175,7 @@ module JSON
     opts = {
       :max_nesting  => false,
       :allow_nan    => true
-    }.update(opts)
+    }.merge(opts)
     Parser.new(source, opts).parse
   end
 
@@ -296,13 +296,13 @@ module JSON
     # The global default options for the JSON.load method:
     #  :max_nesting: false
     #  :allow_nan:   true
-    #  :quirks_mode: true
+    #  :allow_blank:  true
     attr_accessor :load_default_options
   end
   self.load_default_options = {
     :max_nesting      => false,
     :allow_nan        => true,
-    :quirks_mode      => true,
+    :allow_blank       => true,
     :create_additions => true,
   }
 
@@ -329,7 +329,7 @@ module JSON
     elsif source.respond_to?(:read)
       source = source.read
     end
-    if opts[:quirks_mode] && (source.nil? || source.empty?)
+    if opts[:allow_blank] && (source.nil? || source.empty?)
       source = 'null'
     end
     result = parse(source, opts)
@@ -358,13 +358,12 @@ module JSON
     # The global default options for the JSON.dump method:
     #  :max_nesting: false
     #  :allow_nan:   true
-    #  :quirks_mode: true
+    #  :allow_blank: true
     attr_accessor :dump_default_options
   end
   self.dump_default_options = {
     :max_nesting => false,
     :allow_nan   => true,
-    :quirks_mode => true,
   }
 
   # Dumps _obj_ as a JSON string, i.e. calls generate on the object and returns
@@ -403,37 +402,9 @@ module JSON
     raise ArgumentError, "exceed depth limit"
   end
 
-  # Swap consecutive bytes of _string_ in place.
-  def self.swap!(string) # :nodoc:
-    0.upto(string.size / 2) do |i|
-      break unless string[2 * i + 1]
-      string[2 * i], string[2 * i + 1] = string[2 * i + 1], string[2 * i]
-    end
-    string
-  end
-
-  # Shortcut for iconv.
-  if ::String.method_defined?(:encode)
-    # Encodes string using Ruby's _String.encode_
-    def self.iconv(to, from, string)
-      string.encode(to, from)
-    end
-  else
-    require 'iconv'
-    # Encodes string using _iconv_ library
-    def self.iconv(to, from, string)
-      Iconv.conv(to, from, string)
-    end
-  end
-
-  if ::Object.method(:const_defined?).arity == 1
-    def self.const_defined_in?(modul, constant)
-      modul.const_defined?(constant)
-    end
-  else
-    def self.const_defined_in?(modul, constant)
-      modul.const_defined?(constant, false)
-    end
+  # Encodes string using Ruby's _String.encode_
+  def self.iconv(to, from, string)
+    string.encode(to, from)
   end
 end
 
diff --git a/ext/json/lib/json/ext.rb b/ext/json/lib/json/ext.rb
index 2486f084cd..43b8519b34 100644
--- a/ext/json/lib/json/ext.rb
+++ b/ext/json/lib/json/ext.rb
@@ -1,10 +1,4 @@
 # frozen_string_literal: false
-if ENV['SIMPLECOV_COVERAGE'].to_i == 1
-  require 'simplecov'
-  SimpleCov.start do
-    add_filter "/tests/"
-  end
-end
 require 'json/common'
 
 module JSON
diff --git a/ext/json/lib/json/ext/.keep b/ext/json/lib/json/ext/.keep
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/ext/json/lib/json/ext/.keep
diff --git a/ext/json/lib/json/generic_object.rb b/ext/json/lib/json/generic_object.rb
index 2241f6c7ce..8d72d90092 100644
--- a/ext/json/lib/json/generic_object.rb
+++ b/ext/json/lib/json/generic_object.rb
@@ -48,6 +48,14 @@ module JSON
       table
     end
 
+    def [](name)
+      __send__(name)
+    end unless method_defined?(:[])
+
+    def []=(name, value)
+      __send__("#{name}=", value)
+    end unless method_defined?(:[]=)
+
     def |(other)
       self.class[other.to_hash.merge(to_hash)]
     end
diff --git a/ext/json/lib/json/version.rb b/ext/json/lib/json/version.rb
index b5748334b9..5184ad3c19 100644
--- a/ext/json/lib/json/version.rb
+++ b/ext/json/lib/json/version.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 module JSON
   # JSON version
-  VERSION         = '1.8.3'
+  VERSION         = '2.0.1'
   VERSION_ARRAY   = VERSION.split(/\./).map { |x| x.to_i } # :nodoc:
   VERSION_MAJOR   = VERSION_ARRAY[0] # :nodoc:
   VERSION_MINOR   = VERSION_ARRAY[1] # :nodoc:
diff --git a/ext/json/parser/parser.c b/ext/json/parser/parser.c
index 773605cf7c..975a267695 100644
--- a/ext/json/parser/parser.c
+++ b/ext/json/parser/parser.c
@@ -4,7 +4,7 @@
 #include "parser.h"
 
 #if defined HAVE_RUBY_ENCODING_H
-# define EXC_ENCODING UTF_8,
+# define EXC_ENCODING rb_utf8_encoding(),
 # ifndef HAVE_RB_ENC_RAISE
 static void
 enc_raise(rb_encoding *enc, VALUE exc, const char *fmt, ...)
@@ -89,26 +89,20 @@ static int convert_UTF32_to_UTF8(char *buf, UTF32 ch)
     return len;
 }
 
-#ifdef HAVE_RUBY_ENCODING_H
-static rb_encoding *UTF_8, *UTF_16BE, *UTF_16LE, *UTF_32BE, *UTF_32LE;
-#else
-static ID i_iconv;
-#endif
-
 static VALUE mJSON, mExt, cParser, eParserError, eNestingError;
 static VALUE CNaN, CInfinity, CMinusInfinity;
 
 static ID i_json_creatable_p, i_json_create, i_create_id, i_create_additions,
-          i_chr, i_max_nesting, i_allow_nan, i_symbolize_names, i_quirks_mode,
+          i_chr, i_max_nesting, i_allow_nan, i_symbolize_names,
           i_object_class, i_array_class, i_key_p, i_deep_const_get, i_match,
           i_match_string, i_aset, i_aref, i_leftshift;
 
 
-#line 130 "parser.rl"
+#line 124 "parser.rl"
 
 
 
-#line 112 "parser.c"
+#line 106 "parser.c"
 enum {JSON_object_start = 1};
 enum {JSON_object_first_final = 27};
 enum {JSON_object_error = 0};
@@ -116,30 +110,30 @@ enum {JSON_object_error = 0};
 enum {JSON_object_en_main = 1};
 
 
-#line 171 "parser.rl"
+#line 165 "parser.rl"
 
 
-static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *result)
+static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting)
 {
     int cs = EVIL;
     VALUE last_name = Qnil;
     VALUE object_class = json->object_class;
 
-    if (json->max_nesting && json->current_nesting > json->max_nesting) {
-        rb_raise(eNestingError, "nesting of %d is too deep", json->current_nesting);
+    if (json->max_nesting && current_nesting > json->max_nesting) {
+        rb_raise(eNestingError, "nesting of %d is too deep", current_nesting);
     }
 
     *result = NIL_P(object_class) ? rb_hash_new() : rb_class_new_instance(0, 0, object_class);
 
 
-#line 136 "parser.c"
+#line 130 "parser.c"
 	{
 	cs = JSON_object_start;
 	}
 
-#line 186 "parser.rl"
+#line 180 "parser.rl"
 
-#line 143 "parser.c"
+#line 137 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
@@ -167,7 +161,7 @@ case 2:
 		goto st2;
 	goto st0;
 tr2:
-#line 153 "parser.rl"
+#line 147 "parser.rl"
 	{
         char *np;
         json->parsing_name = 1;
@@ -180,7 +174,7 @@ st3:
 	if ( ++p == pe )
 		goto _test_eof3;
 case 3:
-#line 184 "parser.c"
+#line 178 "parser.c"
 	switch( (*p) ) {
 		case 13: goto st3;
 		case 32: goto st3;
@@ -247,10 +241,10 @@ case 8:
 		goto st8;
 	goto st0;
 tr11:
-#line 138 "parser.rl"
+#line 132 "parser.rl"
 	{
         VALUE v = Qnil;
-        char *np = JSON_parse_value(json, p, pe, &v);
+        char *np = JSON_parse_value(json, p, pe, &v, current_nesting);
         if (np == NULL) {
             p--; {p++; cs = 9; goto _out;}
         } else {
@@ -267,7 +261,7 @@ st9:
 	if ( ++p == pe )
 		goto _test_eof9;
 case 9:
-#line 271 "parser.c"
+#line 265 "parser.c"
 	switch( (*p) ) {
 		case 13: goto st9;
 		case 32: goto st9;
@@ -356,14 +350,14 @@ case 18:
 		goto st9;
 	goto st18;
 tr4:
-#line 161 "parser.rl"
+#line 155 "parser.rl"
 	{ p--; {p++; cs = 27; goto _out;} }
 	goto st27;
 st27:
 	if ( ++p == pe )
 		goto _test_eof27;
 case 27:
-#line 367 "parser.c"
+#line 361 "parser.c"
 	goto st0;
 st19:
 	if ( ++p == pe )
@@ -461,7 +455,7 @@ case 26:
 	_out: {}
 	}
 
-#line 187 "parser.rl"
+#line 181 "parser.rl"
 
     if (cs >= JSON_object_first_final) {
         if (json->create_additions) {
@@ -486,69 +480,78 @@ case 26:
 
 
 
-#line 490 "parser.c"
+#line 484 "parser.c"
 enum {JSON_value_start = 1};
-enum {JSON_value_first_final = 21};
+enum {JSON_value_first_final = 29};
 enum {JSON_value_error = 0};
 
 enum {JSON_value_en_main = 1};
 
 
-#line 291 "parser.rl"
+#line 281 "parser.rl"
 
 
-static char *JSON_parse_value(JSON_Parser *json, char *p, char *pe, VALUE *result)
+static char *JSON_parse_value(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting)
 {
     int cs = EVIL;
 
 
-#line 506 "parser.c"
+#line 500 "parser.c"
 	{
 	cs = JSON_value_start;
 	}
 
-#line 298 "parser.rl"
+#line 288 "parser.rl"
 
-#line 513 "parser.c"
+#line 507 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
 	switch ( cs )
 	{
+st1:
+	if ( ++p == pe )
+		goto _test_eof1;
 case 1:
 	switch( (*p) ) {
-		case 34: goto tr0;
-		case 45: goto tr2;
-		case 73: goto st2;
-		case 78: goto st9;
-		case 91: goto tr5;
-		case 102: goto st11;
-		case 110: goto st15;
-		case 116: goto st18;
-		case 123: goto tr9;
+		case 13: goto st1;
+		case 32: goto st1;
+		case 34: goto tr2;
+		case 45: goto tr3;
+		case 47: goto st6;
+		case 73: goto st10;
+		case 78: goto st17;
+		case 91: goto tr7;
+		case 102: goto st19;
+		case 110: goto st23;
+		case 116: goto st26;
+		case 123: goto tr11;
 	}
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr2;
+	if ( (*p) > 10 ) {
+		if ( 48 <= (*p) && (*p) <= 57 )
+			goto tr3;
+	} else if ( (*p) >= 9 )
+		goto st1;
 	goto st0;
 st0:
 cs = 0;
 	goto _out;
-tr0:
-#line 239 "parser.rl"
+tr2:
+#line 233 "parser.rl"
 	{
         char *np = JSON_parse_string(json, p, pe, result);
-        if (np == NULL) { p--; {p++; cs = 21; goto _out;} } else {p = (( np))-1;}
+        if (np == NULL) { p--; {p++; cs = 29; goto _out;} } else {p = (( np))-1;}
     }
-	goto st21;
-tr2:
-#line 244 "parser.rl"
+	goto st29;
+tr3:
+#line 238 "parser.rl"
 	{
         char *np;
-        if(pe > p + 9 - json->quirks_mode && !strncmp(MinusInfinity, p, 9)) {
+        if(pe > p + 8 && !strncmp(MinusInfinity, p, 9)) {
             if (json->allow_nan) {
                 *result = CMinusInfinity;
                 {p = (( p + 10))-1;}
-                p--; {p++; cs = 21; goto _out;}
+                p--; {p++; cs = 29; goto _out;}
             } else {
                 rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
             }
@@ -557,31 +560,27 @@ tr2:
         if (np != NULL) {p = (( np))-1;}
         np = JSON_parse_integer(json, p, pe, result);
         if (np != NULL) {p = (( np))-1;}
-        p--; {p++; cs = 21; goto _out;}
+        p--; {p++; cs = 29; goto _out;}
     }
-	goto st21;
-tr5:
-#line 262 "parser.rl"
+	goto st29;
+tr7:
+#line 256 "parser.rl"
 	{
         char *np;
-        json->current_nesting++;
-        np = JSON_parse_array(json, p, pe, result);
-        json->current_nesting--;
-        if (np == NULL) { p--; {p++; cs = 21; goto _out;} } else {p = (( np))-1;}
+        np = JSON_parse_array(json, p, pe, result, current_nesting + 1);
+        if (np == NULL) { p--; {p++; cs = 29; goto _out;} } else {p = (( np))-1;}
     }
-	goto st21;
-tr9:
-#line 270 "parser.rl"
+	goto st29;
+tr11:
+#line 262 "parser.rl"
 	{
         char *np;
-        json->current_nesting++;
-        np =  JSON_parse_object(json, p, pe, result);
-        json->current_nesting--;
-        if (np == NULL) { p--; {p++; cs = 21; goto _out;} } else {p = (( np))-1;}
+        np =  JSON_parse_object(json, p, pe, result, current_nesting + 1);
+        if (np == NULL) { p--; {p++; cs = 29; goto _out;} } else {p = (( np))-1;}
     }
-	goto st21;
-tr16:
-#line 232 "parser.rl"
+	goto st29;
+tr25:
+#line 226 "parser.rl"
 	{
         if (json->allow_nan) {
             *result = CInfinity;
@@ -589,9 +588,9 @@ tr16:
             rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p - 8);
         }
     }
-	goto st21;
-tr18:
-#line 225 "parser.rl"
+	goto st29;
+tr27:
+#line 219 "parser.rl"
 	{
         if (json->allow_nan) {
             *result = CNaN;
@@ -599,168 +598,240 @@ tr18:
             rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p - 2);
         }
     }
-	goto st21;
-tr22:
-#line 219 "parser.rl"
+	goto st29;
+tr31:
+#line 213 "parser.rl"
 	{
         *result = Qfalse;
     }
-	goto st21;
-tr25:
-#line 216 "parser.rl"
+	goto st29;
+tr34:
+#line 210 "parser.rl"
 	{
         *result = Qnil;
     }
-	goto st21;
-tr28:
-#line 222 "parser.rl"
+	goto st29;
+tr37:
+#line 216 "parser.rl"
 	{
         *result = Qtrue;
     }
-	goto st21;
-st21:
-	if ( ++p == pe )
-		goto _test_eof21;
-case 21:
-#line 278 "parser.rl"
-	{ p--; {p++; cs = 21; goto _out;} }
-#line 628 "parser.c"
+	goto st29;
+st29:
+	if ( ++p == pe )
+		goto _test_eof29;
+case 29:
+#line 268 "parser.rl"
+	{ p--; {p++; cs = 29; goto _out;} }
+#line 627 "parser.c"
+	switch( (*p) ) {
+		case 13: goto st29;
+		case 32: goto st29;
+		case 47: goto st2;
+	}
+	if ( 9 <= (*p) && (*p) <= 10 )
+		goto st29;
 	goto st0;
 st2:
 	if ( ++p == pe )
 		goto _test_eof2;
 case 2:
-	if ( (*p) == 110 )
-		goto st3;
+	switch( (*p) ) {
+		case 42: goto st3;
+		case 47: goto st5;
+	}
 	goto st0;
 st3:
 	if ( ++p == pe )
 		goto _test_eof3;
 case 3:
-	if ( (*p) == 102 )
+	if ( (*p) == 42 )
 		goto st4;
-	goto st0;
+	goto st3;
 st4:
 	if ( ++p == pe )
 		goto _test_eof4;
 case 4:
-	if ( (*p) == 105 )
-		goto st5;
-	goto st0;
+	switch( (*p) ) {
+		case 42: goto st4;
+		case 47: goto st29;
+	}
+	goto st3;
 st5:
 	if ( ++p == pe )
 		goto _test_eof5;
 case 5:
-	if ( (*p) == 110 )
-		goto st6;
-	goto st0;
+	if ( (*p) == 10 )
+		goto st29;
+	goto st5;
 st6:
 	if ( ++p == pe )
 		goto _test_eof6;
 case 6:
-	if ( (*p) == 105 )
-		goto st7;
+	switch( (*p) ) {
+		case 42: goto st7;
+		case 47: goto st9;
+	}
 	goto st0;
 st7:
 	if ( ++p == pe )
 		goto _test_eof7;
 case 7:
-	if ( (*p) == 116 )
+	if ( (*p) == 42 )
 		goto st8;
-	goto st0;
+	goto st7;
 st8:
 	if ( ++p == pe )
 		goto _test_eof8;
 case 8:
-	if ( (*p) == 121 )
-		goto tr16;
-	goto st0;
+	switch( (*p) ) {
+		case 42: goto st8;
+		case 47: goto st1;
+	}
+	goto st7;
 st9:
 	if ( ++p == pe )
 		goto _test_eof9;
 case 9:
-	if ( (*p) == 97 )
-		goto st10;
-	goto st0;
+	if ( (*p) == 10 )
+		goto st1;
+	goto st9;
 st10:
 	if ( ++p == pe )
 		goto _test_eof10;
 case 10:
-	if ( (*p) == 78 )
-		goto tr18;
+	if ( (*p) == 110 )
+		goto st11;
 	goto st0;
 st11:
 	if ( ++p == pe )
 		goto _test_eof11;
 case 11:
-	if ( (*p) == 97 )
+	if ( (*p) == 102 )
 		goto st12;
 	goto st0;
 st12:
 	if ( ++p == pe )
 		goto _test_eof12;
 case 12:
-	if ( (*p) == 108 )
+	if ( (*p) == 105 )
 		goto st13;
 	goto st0;
 st13:
 	if ( ++p == pe )
 		goto _test_eof13;
 case 13:
-	if ( (*p) == 115 )
+	if ( (*p) == 110 )
 		goto st14;
 	goto st0;
 st14:
 	if ( ++p == pe )
 		goto _test_eof14;
 case 14:
-	if ( (*p) == 101 )
-		goto tr22;
+	if ( (*p) == 105 )
+		goto st15;
 	goto st0;
 st15:
 	if ( ++p == pe )
 		goto _test_eof15;
 case 15:
-	if ( (*p) == 117 )
+	if ( (*p) == 116 )
 		goto st16;
 	goto st0;
 st16:
 	if ( ++p == pe )
 		goto _test_eof16;
 case 16:
-	if ( (*p) == 108 )
-		goto st17;
+	if ( (*p) == 121 )
+		goto tr25;
 	goto st0;
 st17:
 	if ( ++p == pe )
 		goto _test_eof17;
 case 17:
-	if ( (*p) == 108 )
-		goto tr25;
+	if ( (*p) == 97 )
+		goto st18;
 	goto st0;
 st18:
 	if ( ++p == pe )
 		goto _test_eof18;
 case 18:
-	if ( (*p) == 114 )
-		goto st19;
+	if ( (*p) == 78 )
+		goto tr27;
 	goto st0;
 st19:
 	if ( ++p == pe )
 		goto _test_eof19;
 case 19:
-	if ( (*p) == 117 )
+	if ( (*p) == 97 )
 		goto st20;
 	goto st0;
 st20:
 	if ( ++p == pe )
 		goto _test_eof20;
 case 20:
+	if ( (*p) == 108 )
+		goto st21;
+	goto st0;
+st21:
+	if ( ++p == pe )
+		goto _test_eof21;
+case 21:
+	if ( (*p) == 115 )
+		goto st22;
+	goto st0;
+st22:
+	if ( ++p == pe )
+		goto _test_eof22;
+case 22:
 	if ( (*p) == 101 )
-		goto tr28;
+		goto tr31;
+	goto st0;
+st23:
+	if ( ++p == pe )
+		goto _test_eof23;
+case 23:
+	if ( (*p) == 117 )
+		goto st24;
+	goto st0;
+st24:
+	if ( ++p == pe )
+		goto _test_eof24;
+case 24:
+	if ( (*p) == 108 )
+		goto st25;
+	goto st0;
+st25:
+	if ( ++p == pe )
+		goto _test_eof25;
+case 25:
+	if ( (*p) == 108 )
+		goto tr34;
+	goto st0;
+st26:
+	if ( ++p == pe )
+		goto _test_eof26;
+case 26:
+	if ( (*p) == 114 )
+		goto st27;
+	goto st0;
+st27:
+	if ( ++p == pe )
+		goto _test_eof27;
+case 27:
+	if ( (*p) == 117 )
+		goto st28;
+	goto st0;
+st28:
+	if ( ++p == pe )
+		goto _test_eof28;
+case 28:
+	if ( (*p) == 101 )
+		goto tr37;
 	goto st0;
 	}
-	_test_eof21: cs = 21; goto _test_eof;
+	_test_eof1: cs = 1; goto _test_eof;
+	_test_eof29: cs = 29; goto _test_eof;
 	_test_eof2: cs = 2; goto _test_eof;
 	_test_eof3: cs = 3; goto _test_eof;
 	_test_eof4: cs = 4; goto _test_eof;
@@ -780,12 +851,20 @@ case 20:
 	_test_eof18: cs = 18; goto _test_eof;
 	_test_eof19: cs = 19; goto _test_eof;
 	_test_eof20: cs = 20; goto _test_eof;
+	_test_eof21: cs = 21; goto _test_eof;
+	_test_eof22: cs = 22; goto _test_eof;
+	_test_eof23: cs = 23; goto _test_eof;
+	_test_eof24: cs = 24; goto _test_eof;
+	_test_eof25: cs = 25; goto _test_eof;
+	_test_eof26: cs = 26; goto _test_eof;
+	_test_eof27: cs = 27; goto _test_eof;
+	_test_eof28: cs = 28; goto _test_eof;
 
 	_test_eof: {}
 	_out: {}
 	}
 
-#line 299 "parser.rl"
+#line 289 "parser.rl"
 
     if (cs >= JSON_value_first_final) {
         return p;
@@ -795,7 +874,7 @@ case 20:
 }
 
 
-#line 799 "parser.c"
+#line 878 "parser.c"
 enum {JSON_integer_start = 1};
 enum {JSON_integer_first_final = 3};
 enum {JSON_integer_error = 0};
@@ -803,7 +882,7 @@ enum {JSON_integer_error = 0};
 enum {JSON_integer_en_main = 1};
 
 
-#line 315 "parser.rl"
+#line 305 "parser.rl"
 
 
 static char *JSON_parse_integer(JSON_Parser *json, char *p, char *pe, VALUE *result)
@@ -811,15 +890,15 @@ static char *JSON_parse_integer(JSON_Parser *json, char *p, char *pe, VALUE *res
     int cs = EVIL;
 
 
-#line 815 "parser.c"
+#line 894 "parser.c"
 	{
 	cs = JSON_integer_start;
 	}
 
-#line 322 "parser.rl"
+#line 312 "parser.rl"
     json->memo = p;
 
-#line 823 "parser.c"
+#line 902 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
@@ -853,14 +932,14 @@ case 3:
 		goto st0;
 	goto tr4;
 tr4:
-#line 312 "parser.rl"
+#line 302 "parser.rl"
 	{ p--; {p++; cs = 4; goto _out;} }
 	goto st4;
 st4:
 	if ( ++p == pe )
 		goto _test_eof4;
 case 4:
-#line 864 "parser.c"
+#line 943 "parser.c"
 	goto st0;
 st5:
 	if ( ++p == pe )
@@ -879,7 +958,7 @@ case 5:
 	_out: {}
 	}
 
-#line 324 "parser.rl"
+#line 314 "parser.rl"
 
     if (cs >= JSON_integer_first_final) {
         long len = p - json->memo;
@@ -894,7 +973,7 @@ case 5:
 }
 
 
-#line 898 "parser.c"
+#line 977 "parser.c"
 enum {JSON_float_start = 1};
 enum {JSON_float_first_final = 8};
 enum {JSON_float_error = 0};
@@ -902,7 +981,7 @@ enum {JSON_float_error = 0};
 enum {JSON_float_en_main = 1};
 
 
-#line 349 "parser.rl"
+#line 339 "parser.rl"
 
 
 static char *JSON_parse_float(JSON_Parser *json, char *p, char *pe, VALUE *result)
@@ -910,15 +989,15 @@ static char *JSON_parse_float(JSON_Parser *json, char *p, char *pe, VALUE *resul
     int cs = EVIL;
 
 
-#line 914 "parser.c"
+#line 993 "parser.c"
 	{
 	cs = JSON_float_start;
 	}
 
-#line 356 "parser.rl"
+#line 346 "parser.rl"
     json->memo = p;
 
-#line 922 "parser.c"
+#line 1001 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
@@ -976,14 +1055,14 @@ case 8:
 		goto st0;
 	goto tr9;
 tr9:
-#line 343 "parser.rl"
+#line 333 "parser.rl"
 	{ p--; {p++; cs = 9; goto _out;} }
 	goto st9;
 st9:
 	if ( ++p == pe )
 		goto _test_eof9;
 case 9:
-#line 987 "parser.c"
+#line 1066 "parser.c"
 	goto st0;
 st5:
 	if ( ++p == pe )
@@ -1044,7 +1123,7 @@ case 7:
 	_out: {}
 	}
 
-#line 358 "parser.rl"
+#line 348 "parser.rl"
 
     if (cs >= JSON_float_first_final) {
         long len = p - json->memo;
@@ -1060,7 +1139,7 @@ case 7:
 
 
 
-#line 1064 "parser.c"
+#line 1143 "parser.c"
 enum {JSON_array_start = 1};
 enum {JSON_array_first_final = 17};
 enum {JSON_array_error = 0};
@@ -1068,28 +1147,28 @@ enum {JSON_array_error = 0};
 enum {JSON_array_en_main = 1};
 
 
-#line 401 "parser.rl"
+#line 391 "parser.rl"
 
 
-static char *JSON_parse_array(JSON_Parser *json, char *p, char *pe, VALUE *result)
+static char *JSON_parse_array(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting)
 {
     int cs = EVIL;
     VALUE array_class = json->array_class;
 
-    if (json->max_nesting && json->current_nesting > json->max_nesting) {
-        rb_raise(eNestingError, "nesting of %d is too deep", json->current_nesting);
+    if (json->max_nesting && current_nesting > json->max_nesting) {
+        rb_raise(eNestingError, "nesting of %d is too deep", current_nesting);
     }
     *result = NIL_P(array_class) ? rb_ary_new() : rb_class_new_instance(0, 0, array_class);
 
 
-#line 1086 "parser.c"
+#line 1165 "parser.c"
 	{
 	cs = JSON_array_start;
 	}
 
-#line 414 "parser.rl"
+#line 404 "parser.rl"
 
-#line 1093 "parser.c"
+#line 1172 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
@@ -1128,10 +1207,10 @@ case 2:
 		goto st2;
 	goto st0;
 tr2:
-#line 378 "parser.rl"
+#line 368 "parser.rl"
 	{
         VALUE v = Qnil;
-        char *np = JSON_parse_value(json, p, pe, &v);
+        char *np = JSON_parse_value(json, p, pe, &v, current_nesting);
         if (np == NULL) {
             p--; {p++; cs = 3; goto _out;}
         } else {
@@ -1148,7 +1227,7 @@ st3:
 	if ( ++p == pe )
 		goto _test_eof3;
 case 3:
-#line 1152 "parser.c"
+#line 1231 "parser.c"
 	switch( (*p) ) {
 		case 13: goto st3;
 		case 32: goto st3;
@@ -1248,14 +1327,14 @@ case 12:
 		goto st3;
 	goto st12;
 tr4:
-#line 393 "parser.rl"
+#line 383 "parser.rl"
 	{ p--; {p++; cs = 17; goto _out;} }
 	goto st17;
 st17:
 	if ( ++p == pe )
 		goto _test_eof17;
 case 17:
-#line 1259 "parser.c"
+#line 1338 "parser.c"
 	goto st0;
 st13:
 	if ( ++p == pe )
@@ -1311,7 +1390,7 @@ case 16:
 	_out: {}
 	}
 
-#line 415 "parser.rl"
+#line 405 "parser.rl"
 
     if(cs >= JSON_array_first_final) {
         return p + 1;
@@ -1392,7 +1471,7 @@ static VALUE json_string_unescape(VALUE result, char *string, char *stringEnd)
 }
 
 
-#line 1396 "parser.c"
+#line 1475 "parser.c"
 enum {JSON_string_start = 1};
 enum {JSON_string_first_final = 8};
 enum {JSON_string_error = 0};
@@ -1400,7 +1479,7 @@ enum {JSON_string_error = 0};
 enum {JSON_string_en_main = 1};
 
 
-#line 514 "parser.rl"
+#line 504 "parser.rl"
 
 
 static int
@@ -1422,15 +1501,15 @@ static char *JSON_parse_string(JSON_Parser *json, char *p, char *pe, VALUE *resu
 
     *result = rb_str_buf_new(0);
 
-#line 1426 "parser.c"
+#line 1505 "parser.c"
 	{
 	cs = JSON_string_start;
 	}
 
-#line 535 "parser.rl"
+#line 525 "parser.rl"
     json->memo = p;
 
-#line 1434 "parser.c"
+#line 1513 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
@@ -1455,7 +1534,7 @@ case 2:
 		goto st0;
 	goto st2;
 tr2:
-#line 500 "parser.rl"
+#line 490 "parser.rl"
 	{
         *result = json_string_unescape(*result, json->memo + 1, p);
         if (NIL_P(*result)) {
@@ -1466,14 +1545,14 @@ tr2:
             {p = (( p + 1))-1;}
         }
     }
-#line 511 "parser.rl"
+#line 501 "parser.rl"
 	{ p--; {p++; cs = 8; goto _out;} }
 	goto st8;
 st8:
 	if ( ++p == pe )
 		goto _test_eof8;
 case 8:
-#line 1477 "parser.c"
+#line 1556 "parser.c"
 	goto st0;
 st3:
 	if ( ++p == pe )
@@ -1549,7 +1628,7 @@ case 7:
 	_out: {}
 	}
 
-#line 537 "parser.rl"
+#line 527 "parser.rl"
 
     if (json->create_additions && RTEST(match_string = json->match_string)) {
           VALUE klass;
@@ -1564,6 +1643,8 @@ case 7:
 
     if (json->symbolize_names && json->parsing_name) {
       *result = rb_str_intern(*result);
+    } else {
+      rb_str_resize(*result, RSTRING_LEN(*result));
     }
     if (cs >= JSON_string_first_final) {
         return p + 1;
@@ -1586,41 +1667,13 @@ case 7:
 
 static VALUE convert_encoding(VALUE source)
 {
-    const char *ptr = RSTRING_PTR(source);
-    long len = RSTRING_LEN(source);
-    if (len < 2) {
-        rb_raise(eParserError, "A JSON text must at least contain two octets!");
-    }
 #ifdef HAVE_RUBY_ENCODING_H
-    {
-        rb_encoding *enc = rb_enc_get(source);
-        if (enc == rb_ascii8bit_encoding()) {
-            if (len >= 4 &&  ptr[0] == 0 && ptr[1] == 0 && ptr[2] == 0) {
-                source = rb_str_conv_enc(source, UTF_32BE, rb_utf8_encoding());
-            } else if (len >= 4 && ptr[0] == 0 && ptr[2] == 0) {
-                source = rb_str_conv_enc(source, UTF_16BE, rb_utf8_encoding());
-            } else if (len >= 4 && ptr[1] == 0 && ptr[2] == 0 && ptr[3] == 0) {
-                source = rb_str_conv_enc(source, UTF_32LE, rb_utf8_encoding());
-            } else if (len >= 4 && ptr[1] == 0 && ptr[3] == 0) {
-                source = rb_str_conv_enc(source, UTF_16LE, rb_utf8_encoding());
-            } else {
-                source = rb_str_dup(source);
-                FORCE_UTF8(source);
-            }
-        } else {
-            source = rb_str_conv_enc(source, NULL, rb_utf8_encoding());
-        }
-    }
-#else
-    if (len >= 4 &&  ptr[0] == 0 && ptr[1] == 0 && ptr[2] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-32be"), source);
-    } else if (len >= 4 && ptr[0] == 0 && ptr[2] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-16be"), source);
-    } else if (len >= 4 && ptr[1] == 0 && ptr[2] == 0 && ptr[3] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-32le"), source);
-    } else if (len >= 4 && ptr[1] == 0 && ptr[3] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-16le"), source);
-    }
+  rb_encoding *enc = rb_enc_get(source);
+  if (enc == rb_ascii8bit_encoding()) {
+    FORCE_UTF8(source);
+  } else {
+    source = rb_str_conv_enc(source, NULL, rb_utf8_encoding());
+  }
 #endif
     return source;
 }
@@ -1643,8 +1696,9 @@ static VALUE convert_encoding(VALUE source)
  *   defiance of RFC 4627 to be parsed by the Parser. This option defaults to
  *   false.
  * * *symbolize_names*: If set to true, returns symbols for the names
- *   (keys) in a JSON object. Otherwise strings are returned, which is also
- *   the default.
+ *   (keys) in a JSON object. Otherwise strings are returned, which is
+ *   also the default. It's not possible to use this option in
+ *   conjunction with the *create_additions* option.
  * * *create_additions*: If set to false, the Parser doesn't create
  *   additions even if a matching class and create_id was found. This option
  *   defaults to false.
@@ -1695,19 +1749,17 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
             } else {
                 json->symbolize_names = 0;
             }
-            tmp = ID2SYM(i_quirks_mode);
-            if (option_given_p(opts, tmp)) {
-                VALUE quirks_mode = rb_hash_aref(opts, tmp);
-                json->quirks_mode = RTEST(quirks_mode) ? 1 : 0;
-            } else {
-                json->quirks_mode = 0;
-            }
             tmp = ID2SYM(i_create_additions);
             if (option_given_p(opts, tmp)) {
                 json->create_additions = RTEST(rb_hash_aref(opts, tmp));
             } else {
                 json->create_additions = 0;
             }
+            if (json->symbolize_names && json->create_additions) {
+              rb_raise(rb_eArgError,
+                "options :symbolize_names and :create_additions cannot be "
+                " used in conjunction");
+            }
             tmp = ID2SYM(i_create_id);
             if (option_given_p(opts, tmp)) {
                 json->create_id = rb_hash_aref(opts, tmp);
@@ -1744,11 +1796,8 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
         json->object_class = Qnil;
         json->array_class = Qnil;
     }
+    source = convert_encoding(StringValue(source));
     StringValue(source);
-    if (!json->quirks_mode) {
-	source = convert_encoding(source);
-    }
-    json->current_nesting = 0;
     json->len = RSTRING_LEN(source);
     json->source = RSTRING_PTR(source);;
     json->Vsource = source;
@@ -1756,7 +1805,7 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
 }
 
 
-#line 1760 "parser.c"
+#line 1809 "parser.c"
 enum {JSON_start = 1};
 enum {JSON_first_final = 10};
 enum {JSON_error = 0};
@@ -1764,201 +1813,33 @@ enum {JSON_error = 0};
 enum {JSON_en_main = 1};
 
 
-#line 767 "parser.rl"
+#line 717 "parser.rl"
 
 
-static VALUE cParser_parse_strict(VALUE self)
+/*
+ * call-seq: parse()
+ *
+ *  Parses the current JSON text _source_ and returns the complete data
+ *  structure as a result.
+ */
+static VALUE cParser_parse(VALUE self)
 {
-    char *p, *pe;
-    int cs = EVIL;
-    VALUE result = Qnil;
-    GET_PARSER;
+  char *p, *pe;
+  int cs = EVIL;
+  VALUE result = Qnil;
+  GET_PARSER;
 
 
-#line 1779 "parser.c"
+#line 1834 "parser.c"
 	{
 	cs = JSON_start;
 	}
 
-#line 777 "parser.rl"
-    p = json->source;
-    pe = p + json->len;
+#line 733 "parser.rl"
+  p = json->source;
+  pe = p + json->len;
 
-#line 1788 "parser.c"
-	{
-	if ( p == pe )
-		goto _test_eof;
-	switch ( cs )
-	{
-st1:
-	if ( ++p == pe )
-		goto _test_eof1;
-case 1:
-	switch( (*p) ) {
-		case 13: goto st1;
-		case 32: goto st1;
-		case 47: goto st2;
-		case 91: goto tr3;
-		case 123: goto tr4;
-	}
-	if ( 9 <= (*p) && (*p) <= 10 )
-		goto st1;
-	goto st0;
-st0:
-cs = 0;
-	goto _out;
-st2:
-	if ( ++p == pe )
-		goto _test_eof2;
-case 2:
-	switch( (*p) ) {
-		case 42: goto st3;
-		case 47: goto st5;
-	}
-	goto st0;
-st3:
-	if ( ++p == pe )
-		goto _test_eof3;
-case 3:
-	if ( (*p) == 42 )
-		goto st4;
-	goto st3;
-st4:
-	if ( ++p == pe )
-		goto _test_eof4;
-case 4:
-	switch( (*p) ) {
-		case 42: goto st4;
-		case 47: goto st1;
-	}
-	goto st3;
-st5:
-	if ( ++p == pe )
-		goto _test_eof5;
-case 5:
-	if ( (*p) == 10 )
-		goto st1;
-	goto st5;
-tr3:
-#line 756 "parser.rl"
-	{
-        char *np;
-        json->current_nesting = 1;
-        np = JSON_parse_array(json, p, pe, &result);
-        if (np == NULL) { p--; {p++; cs = 10; goto _out;} } else {p = (( np))-1;}
-    }
-	goto st10;
-tr4:
-#line 749 "parser.rl"
-	{
-        char *np;
-        json->current_nesting = 1;
-        np = JSON_parse_object(json, p, pe, &result);
-        if (np == NULL) { p--; {p++; cs = 10; goto _out;} } else {p = (( np))-1;}
-    }
-	goto st10;
-st10:
-	if ( ++p == pe )
-		goto _test_eof10;
-case 10:
-#line 1865 "parser.c"
-	switch( (*p) ) {
-		case 13: goto st10;
-		case 32: goto st10;
-		case 47: goto st6;
-	}
-	if ( 9 <= (*p) && (*p) <= 10 )
-		goto st10;
-	goto st0;
-st6:
-	if ( ++p == pe )
-		goto _test_eof6;
-case 6:
-	switch( (*p) ) {
-		case 42: goto st7;
-		case 47: goto st9;
-	}
-	goto st0;
-st7:
-	if ( ++p == pe )
-		goto _test_eof7;
-case 7:
-	if ( (*p) == 42 )
-		goto st8;
-	goto st7;
-st8:
-	if ( ++p == pe )
-		goto _test_eof8;
-case 8:
-	switch( (*p) ) {
-		case 42: goto st8;
-		case 47: goto st10;
-	}
-	goto st7;
-st9:
-	if ( ++p == pe )
-		goto _test_eof9;
-case 9:
-	if ( (*p) == 10 )
-		goto st10;
-	goto st9;
-	}
-	_test_eof1: cs = 1; goto _test_eof;
-	_test_eof2: cs = 2; goto _test_eof;
-	_test_eof3: cs = 3; goto _test_eof;
-	_test_eof4: cs = 4; goto _test_eof;
-	_test_eof5: cs = 5; goto _test_eof;
-	_test_eof10: cs = 10; goto _test_eof;
-	_test_eof6: cs = 6; goto _test_eof;
-	_test_eof7: cs = 7; goto _test_eof;
-	_test_eof8: cs = 8; goto _test_eof;
-	_test_eof9: cs = 9; goto _test_eof;
-
-	_test_eof: {}
-	_out: {}
-	}
-
-#line 780 "parser.rl"
-
-    if (cs >= JSON_first_final && p == pe) {
-        return result;
-    } else {
-        rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
-        return Qnil;
-    }
-}
-
-
-
-#line 1934 "parser.c"
-enum {JSON_quirks_mode_start = 1};
-enum {JSON_quirks_mode_first_final = 10};
-enum {JSON_quirks_mode_error = 0};
-
-enum {JSON_quirks_mode_en_main = 1};
-
-
-#line 805 "parser.rl"
-
-
-static VALUE cParser_parse_quirks_mode(VALUE self)
-{
-    char *p, *pe;
-    int cs = EVIL;
-    VALUE result = Qnil;
-    GET_PARSER;
-
-
-#line 1953 "parser.c"
-	{
-	cs = JSON_quirks_mode_start;
-	}
-
-#line 815 "parser.rl"
-    p = json->source;
-    pe = p + json->len;
-
-#line 1962 "parser.c"
+#line 1843 "parser.c"
 	{
 	if ( p == pe )
 		goto _test_eof;
@@ -1992,9 +1873,9 @@ st0:
 cs = 0;
 	goto _out;
 tr2:
-#line 797 "parser.rl"
+#line 709 "parser.rl"
 	{
-        char *np = JSON_parse_value(json, p, pe, &result);
+        char *np = JSON_parse_value(json, p, pe, &result, 0);
         if (np == NULL) { p--; {p++; cs = 10; goto _out;} } else {p = (( np))-1;}
     }
 	goto st10;
@@ -2002,7 +1883,7 @@ st10:
 	if ( ++p == pe )
 		goto _test_eof10;
 case 10:
-#line 2006 "parser.c"
+#line 1887 "parser.c"
 	switch( (*p) ) {
 		case 13: goto st10;
 		case 32: goto st10;
@@ -2091,30 +1972,13 @@ case 9:
 	_out: {}
 	}
 
-#line 818 "parser.rl"
-
-    if (cs >= JSON_quirks_mode_first_final && p == pe) {
-        return result;
-    } else {
-        rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
-        return Qnil;
-    }
-}
+#line 736 "parser.rl"
 
-/*
- * call-seq: parse()
- *
- *  Parses the current JSON text _source_ and returns the complete data
- *  structure as a result.
- */
-static VALUE cParser_parse(VALUE self)
-{
-  GET_PARSER;
-
-  if (json->quirks_mode) {
-    return cParser_parse_quirks_mode(self);
+  if (cs >= JSON_first_final && p == pe) {
+    return result;
   } else {
-    return cParser_parse_strict(self);
+    rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
+    return Qnil;
   }
 }
 
@@ -2172,18 +2036,6 @@ static VALUE cParser_source(VALUE self)
     return rb_str_dup(json->Vsource);
 }
 
-/*
- * call-seq: quirks_mode?()
- *
- * Returns a true, if this parser is in quirks_mode, false otherwise.
- */
-static VALUE cParser_quirks_mode_p(VALUE self)
-{
-    GET_PARSER;
-    return json->quirks_mode ? Qtrue : Qfalse;
-}
-
-
 void Init_parser(void)
 {
     rb_require("json/common");
@@ -2196,7 +2048,6 @@ void Init_parser(void)
     rb_define_method(cParser, "initialize", cParser_initialize, -1);
     rb_define_method(cParser, "parse", cParser_parse, 0);
     rb_define_method(cParser, "source", cParser_source, 0);
-    rb_define_method(cParser, "quirks_mode?", cParser_quirks_mode_p, 0);
 
     CNaN = rb_const_get(mJSON, rb_intern("NaN"));
     CInfinity = rb_const_get(mJSON, rb_intern("Infinity"));
@@ -2210,7 +2061,6 @@ void Init_parser(void)
     i_max_nesting = rb_intern("max_nesting");
     i_allow_nan = rb_intern("allow_nan");
     i_symbolize_names = rb_intern("symbolize_names");
-    i_quirks_mode = rb_intern("quirks_mode");
     i_object_class = rb_intern("object_class");
     i_array_class = rb_intern("array_class");
     i_match = rb_intern("match");
@@ -2220,15 +2070,6 @@ void Init_parser(void)
     i_aset = rb_intern("[]=");
     i_aref = rb_intern("[]");
     i_leftshift = rb_intern("<<");
-#ifdef HAVE_RUBY_ENCODING_H
-    UTF_8 = rb_utf8_encoding();
-    UTF_16BE = rb_enc_find("utf-16be");
-    UTF_16LE = rb_enc_find("utf-16le");
-    UTF_32BE = rb_enc_find("utf-32be");
-    UTF_32LE = rb_enc_find("utf-32le");
-#else
-    i_iconv = rb_intern("iconv");
-#endif
 }
 
 /*
diff --git a/ext/json/parser/parser.h b/ext/json/parser/parser.h
index abcc2571f1..1d46831965 100644
--- a/ext/json/parser/parser.h
+++ b/ext/json/parser/parser.h
@@ -34,11 +34,9 @@ typedef struct JSON_ParserStruct {
     char *memo;
     VALUE create_id;
     int max_nesting;
-    int current_nesting;
     int allow_nan;
     int parsing_name;
     int symbolize_names;
-    int quirks_mode;
     VALUE object_class;
     VALUE array_class;
     int create_additions;
@@ -58,11 +56,11 @@ typedef struct JSON_ParserStruct {
 
 static UTF32 unescape_unicode(const unsigned char *p);
 static int convert_UTF32_to_UTF8(char *buf, UTF32 ch);
-static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *result);
-static char *JSON_parse_value(JSON_Parser *json, char *p, char *pe, VALUE *result);
+static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting);
+static char *JSON_parse_value(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting);
 static char *JSON_parse_integer(JSON_Parser *json, char *p, char *pe, VALUE *result);
 static char *JSON_parse_float(JSON_Parser *json, char *p, char *pe, VALUE *result);
-static char *JSON_parse_array(JSON_Parser *json, char *p, char *pe, VALUE *result);
+static char *JSON_parse_array(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting);
 static VALUE json_string_unescape(VALUE result, char *string, char *stringEnd);
 static char *JSON_parse_string(JSON_Parser *json, char *p, char *pe, VALUE *result);
 static VALUE convert_encoding(VALUE source);
diff --git a/ext/json/parser/parser.rl b/ext/json/parser/parser.rl
index 2fa0caee7a..c67634b8ba 100644
--- a/ext/json/parser/parser.rl
+++ b/ext/json/parser/parser.rl
@@ -2,7 +2,7 @@
 #include "parser.h"
 
 #if defined HAVE_RUBY_ENCODING_H
-# define EXC_ENCODING UTF_8,
+# define EXC_ENCODING rb_utf8_encoding(),
 # ifndef HAVE_RB_ENC_RAISE
 static void
 enc_raise(rb_encoding *enc, VALUE exc, const char *fmt, ...)
@@ -87,17 +87,11 @@ static int convert_UTF32_to_UTF8(char *buf, UTF32 ch)
     return len;
 }
 
-#ifdef HAVE_RUBY_ENCODING_H
-static rb_encoding *UTF_8, *UTF_16BE, *UTF_16LE, *UTF_32BE, *UTF_32LE;
-#else
-static ID i_iconv;
-#endif
-
 static VALUE mJSON, mExt, cParser, eParserError, eNestingError;
 static VALUE CNaN, CInfinity, CMinusInfinity;
 
 static ID i_json_creatable_p, i_json_create, i_create_id, i_create_additions,
-          i_chr, i_max_nesting, i_allow_nan, i_symbolize_names, i_quirks_mode,
+          i_chr, i_max_nesting, i_allow_nan, i_symbolize_names,
           i_object_class, i_array_class, i_key_p, i_deep_const_get, i_match,
           i_match_string, i_aset, i_aref, i_leftshift;
 
@@ -137,7 +131,7 @@ static ID i_json_creatable_p, i_json_create, i_create_id, i_create_additions,
 
     action parse_value {
         VALUE v = Qnil;
-        char *np = JSON_parse_value(json, fpc, pe, &v);
+        char *np = JSON_parse_value(json, fpc, pe, &v, current_nesting);
         if (np == NULL) {
             fhold; fbreak;
         } else {
@@ -170,14 +164,14 @@ static ID i_json_creatable_p, i_json_create, i_create_id, i_create_additions,
     ) @exit;
 }%%
 
-static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *result)
+static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting)
 {
     int cs = EVIL;
     VALUE last_name = Qnil;
     VALUE object_class = json->object_class;
 
-    if (json->max_nesting && json->current_nesting > json->max_nesting) {
-        rb_raise(eNestingError, "nesting of %d is too deep", json->current_nesting);
+    if (json->max_nesting && current_nesting > json->max_nesting) {
+        rb_raise(eNestingError, "nesting of %d is too deep", current_nesting);
     }
 
     *result = NIL_P(object_class) ? rb_hash_new() : rb_class_new_instance(0, 0, object_class);
@@ -243,7 +237,7 @@ static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *resu
 
     action parse_number {
         char *np;
-        if(pe > fpc + 9 - json->quirks_mode && !strncmp(MinusInfinity, fpc, 9)) {
+        if(pe > fpc + 8 && !strncmp(MinusInfinity, fpc, 9)) {
             if (json->allow_nan) {
                 *result = CMinusInfinity;
                 fexec p + 10;
@@ -261,23 +255,19 @@ static char *JSON_parse_object(JSON_Parser *json, char *p, char *pe, VALUE *resu
 
     action parse_array {
         char *np;
-        json->current_nesting++;
-        np = JSON_parse_array(json, fpc, pe, result);
-        json->current_nesting--;
+        np = JSON_parse_array(json, fpc, pe, result, current_nesting + 1);
         if (np == NULL) { fhold; fbreak; } else fexec np;
     }
 
     action parse_object {
         char *np;
-        json->current_nesting++;
-        np =  JSON_parse_object(json, fpc, pe, result);
-        json->current_nesting--;
+        np =  JSON_parse_object(json, fpc, pe, result, current_nesting + 1);
         if (np == NULL) { fhold; fbreak; } else fexec np;
     }
 
     action exit { fhold; fbreak; }
 
-main := (
+main := ignore* (
               Vnull @parse_null |
               Vfalse @parse_false |
               Vtrue @parse_true |
@@ -287,10 +277,10 @@ main := (
               begin_string >parse_string |
               begin_array >parse_array |
               begin_object >parse_object
-        ) %*exit;
+        ) ignore* %*exit;
 }%%
 
-static char *JSON_parse_value(JSON_Parser *json, char *p, char *pe, VALUE *result)
+static char *JSON_parse_value(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting)
 {
     int cs = EVIL;
 
@@ -377,7 +367,7 @@ static char *JSON_parse_float(JSON_Parser *json, char *p, char *pe, VALUE *resul
 
     action parse_value {
         VALUE v = Qnil;
-        char *np = JSON_parse_value(json, fpc, pe, &v);
+        char *np = JSON_parse_value(json, fpc, pe, &v, current_nesting);
         if (np == NULL) {
             fhold; fbreak;
         } else {
@@ -400,13 +390,13 @@ static char *JSON_parse_float(JSON_Parser *json, char *p, char *pe, VALUE *resul
           end_array @exit;
 }%%
 
-static char *JSON_parse_array(JSON_Parser *json, char *p, char *pe, VALUE *result)
+static char *JSON_parse_array(JSON_Parser *json, char *p, char *pe, VALUE *result, int current_nesting)
 {
     int cs = EVIL;
     VALUE array_class = json->array_class;
 
-    if (json->max_nesting && json->current_nesting > json->max_nesting) {
-        rb_raise(eNestingError, "nesting of %d is too deep", json->current_nesting);
+    if (json->max_nesting && current_nesting > json->max_nesting) {
+        rb_raise(eNestingError, "nesting of %d is too deep", current_nesting);
     }
     *result = NIL_P(array_class) ? rb_ary_new() : rb_class_new_instance(0, 0, array_class);
 
@@ -548,6 +538,8 @@ static char *JSON_parse_string(JSON_Parser *json, char *p, char *pe, VALUE *resu
 
     if (json->symbolize_names && json->parsing_name) {
       *result = rb_str_intern(*result);
+    } else {
+      rb_str_resize(*result, RSTRING_LEN(*result));
     }
     if (cs >= JSON_string_first_final) {
         return p + 1;
@@ -570,41 +562,13 @@ static char *JSON_parse_string(JSON_Parser *json, char *p, char *pe, VALUE *resu
 
 static VALUE convert_encoding(VALUE source)
 {
-    const char *ptr = RSTRING_PTR(source);
-    long len = RSTRING_LEN(source);
-    if (len < 2) {
-        rb_raise(eParserError, "A JSON text must at least contain two octets!");
-    }
 #ifdef HAVE_RUBY_ENCODING_H
-    {
-        rb_encoding *enc = rb_enc_get(source);
-        if (enc == rb_ascii8bit_encoding()) {
-            if (len >= 4 &&  ptr[0] == 0 && ptr[1] == 0 && ptr[2] == 0) {
-                source = rb_str_conv_enc(source, UTF_32BE, rb_utf8_encoding());
-            } else if (len >= 4 && ptr[0] == 0 && ptr[2] == 0) {
-                source = rb_str_conv_enc(source, UTF_16BE, rb_utf8_encoding());
-            } else if (len >= 4 && ptr[1] == 0 && ptr[2] == 0 && ptr[3] == 0) {
-                source = rb_str_conv_enc(source, UTF_32LE, rb_utf8_encoding());
-            } else if (len >= 4 && ptr[1] == 0 && ptr[3] == 0) {
-                source = rb_str_conv_enc(source, UTF_16LE, rb_utf8_encoding());
-            } else {
-                source = rb_str_dup(source);
-                FORCE_UTF8(source);
-            }
-        } else {
-            source = rb_str_conv_enc(source, NULL, rb_utf8_encoding());
-        }
-    }
-#else
-    if (len >= 4 &&  ptr[0] == 0 && ptr[1] == 0 && ptr[2] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-32be"), source);
-    } else if (len >= 4 && ptr[0] == 0 && ptr[2] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-16be"), source);
-    } else if (len >= 4 && ptr[1] == 0 && ptr[2] == 0 && ptr[3] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-32le"), source);
-    } else if (len >= 4 && ptr[1] == 0 && ptr[3] == 0) {
-      source = rb_funcall(mJSON, i_iconv, 3, rb_str_new2("utf-8"), rb_str_new2("utf-16le"), source);
-    }
+  rb_encoding *enc = rb_enc_get(source);
+  if (enc == rb_ascii8bit_encoding()) {
+    FORCE_UTF8(source);
+  } else {
+    source = rb_str_conv_enc(source, NULL, rb_utf8_encoding());
+  }
 #endif
     return source;
 }
@@ -627,8 +591,9 @@ static VALUE convert_encoding(VALUE source)
  *   defiance of RFC 4627 to be parsed by the Parser. This option defaults to
  *   false.
  * * *symbolize_names*: If set to true, returns symbols for the names
- *   (keys) in a JSON object. Otherwise strings are returned, which is also
- *   the default.
+ *   (keys) in a JSON object. Otherwise strings are returned, which is
+ *   also the default. It's not possible to use this option in
+ *   conjunction with the *create_additions* option.
  * * *create_additions*: If set to false, the Parser doesn't create
  *   additions even if a matching class and create_id was found. This option
  *   defaults to false.
@@ -679,19 +644,17 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
             } else {
                 json->symbolize_names = 0;
             }
-            tmp = ID2SYM(i_quirks_mode);
-            if (option_given_p(opts, tmp)) {
-                VALUE quirks_mode = rb_hash_aref(opts, tmp);
-                json->quirks_mode = RTEST(quirks_mode) ? 1 : 0;
-            } else {
-                json->quirks_mode = 0;
-            }
             tmp = ID2SYM(i_create_additions);
             if (option_given_p(opts, tmp)) {
                 json->create_additions = RTEST(rb_hash_aref(opts, tmp));
             } else {
                 json->create_additions = 0;
             }
+            if (json->symbolize_names && json->create_additions) {
+              rb_raise(rb_eArgError,
+                "options :symbolize_names and :create_additions cannot be "
+                " used in conjunction");
+            }
             tmp = ID2SYM(i_create_id);
             if (option_given_p(opts, tmp)) {
                 json->create_id = rb_hash_aref(opts, tmp);
@@ -728,11 +691,8 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
         json->object_class = Qnil;
         json->array_class = Qnil;
     }
+    source = convert_encoding(StringValue(source));
     StringValue(source);
-    if (!json->quirks_mode) {
-	source = convert_encoding(source);
-    }
-    json->current_nesting = 0;
     json->len = RSTRING_LEN(source);
     json->source = RSTRING_PTR(source);;
     json->Vsource = source;
@@ -746,56 +706,8 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
 
     include JSON_common;
 
-    action parse_object {
-        char *np;
-        json->current_nesting = 1;
-        np = JSON_parse_object(json, fpc, pe, &result);
-        if (np == NULL) { fhold; fbreak; } else fexec np;
-    }
-
-    action parse_array {
-        char *np;
-        json->current_nesting = 1;
-        np = JSON_parse_array(json, fpc, pe, &result);
-        if (np == NULL) { fhold; fbreak; } else fexec np;
-    }
-
-    main := ignore* (
-            begin_object >parse_object |
-            begin_array >parse_array
-            ) ignore*;
-}%%
-
-static VALUE cParser_parse_strict(VALUE self)
-{
-    char *p, *pe;
-    int cs = EVIL;
-    VALUE result = Qnil;
-    GET_PARSER;
-
-    %% write init;
-    p = json->source;
-    pe = p + json->len;
-    %% write exec;
-
-    if (cs >= JSON_first_final && p == pe) {
-        return result;
-    } else {
-        rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
-        return Qnil;
-    }
-}
-
-
-%%{
-    machine JSON_quirks_mode;
-
-    write data;
-
-    include JSON_common;
-
     action parse_value {
-        char *np = JSON_parse_value(json, fpc, pe, &result);
+        char *np = JSON_parse_value(json, fpc, pe, &result, 0);
         if (np == NULL) { fhold; fbreak; } else fexec np;
     }
 
@@ -804,26 +716,6 @@ static VALUE cParser_parse_strict(VALUE self)
             ) ignore*;
 }%%
 
-static VALUE cParser_parse_quirks_mode(VALUE self)
-{
-    char *p, *pe;
-    int cs = EVIL;
-    VALUE result = Qnil;
-    GET_PARSER;
-
-    %% write init;
-    p = json->source;
-    pe = p + json->len;
-    %% write exec;
-
-    if (cs >= JSON_quirks_mode_first_final && p == pe) {
-        return result;
-    } else {
-        rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
-        return Qnil;
-    }
-}
-
 /*
  * call-seq: parse()
  *
@@ -832,12 +724,21 @@ static VALUE cParser_parse_quirks_mode(VALUE self)
  */
 static VALUE cParser_parse(VALUE self)
 {
+  char *p, *pe;
+  int cs = EVIL;
+  VALUE result = Qnil;
   GET_PARSER;
 
-  if (json->quirks_mode) {
-    return cParser_parse_quirks_mode(self);
+  %% write init;
+  p = json->source;
+  pe = p + json->len;
+  %% write exec;
+
+  if (cs >= JSON_first_final && p == pe) {
+    return result;
   } else {
-    return cParser_parse_strict(self);
+    rb_enc_raise(EXC_ENCODING eParserError, "%u: unexpected token at '%s'", __LINE__, p);
+    return Qnil;
   }
 }
 
@@ -895,18 +796,6 @@ static VALUE cParser_source(VALUE self)
     return rb_str_dup(json->Vsource);
 }
 
-/*
- * call-seq: quirks_mode?()
- *
- * Returns a true, if this parser is in quirks_mode, false otherwise.
- */
-static VALUE cParser_quirks_mode_p(VALUE self)
-{
-    GET_PARSER;
-    return json->quirks_mode ? Qtrue : Qfalse;
-}
-
-
 void Init_parser(void)
 {
     rb_require("json/common");
@@ -919,7 +808,6 @@ void Init_parser(void)
     rb_define_method(cParser, "initialize", cParser_initialize, -1);
     rb_define_method(cParser, "parse", cParser_parse, 0);
     rb_define_method(cParser, "source", cParser_source, 0);
-    rb_define_method(cParser, "quirks_mode?", cParser_quirks_mode_p, 0);
 
     CNaN = rb_const_get(mJSON, rb_intern("NaN"));
     CInfinity = rb_const_get(mJSON, rb_intern("Infinity"));
@@ -933,7 +821,6 @@ void Init_parser(void)
     i_max_nesting = rb_intern("max_nesting");
     i_allow_nan = rb_intern("allow_nan");
     i_symbolize_names = rb_intern("symbolize_names");
-    i_quirks_mode = rb_intern("quirks_mode");
     i_object_class = rb_intern("object_class");
     i_array_class = rb_intern("array_class");
     i_match = rb_intern("match");
@@ -943,15 +830,6 @@ void Init_parser(void)
     i_aset = rb_intern("[]=");
     i_aref = rb_intern("[]");
     i_leftshift = rb_intern("<<");
-#ifdef HAVE_RUBY_ENCODING_H
-    UTF_8 = rb_utf8_encoding();
-    UTF_16BE = rb_enc_find("utf-16be");
-    UTF_16LE = rb_enc_find("utf-16le");
-    UTF_32BE = rb_enc_find("utf-32be");
-    UTF_32LE = rb_enc_find("utf-32le");
-#else
-    i_iconv = rb_intern("iconv");
-#endif
 }
 
 /*
diff --git a/ext/json/parser/prereq.mk b/ext/json/parser/prereq.mk
deleted file mode 100644
index be7bcb4319..0000000000
--- a/ext/json/parser/prereq.mk
+++ /dev/null
@@ -1,10 +0,0 @@
-RAGEL = ragel
-
-.SUFFIXES: .rl
-
-.rl.c:
-	$(RAGEL) -G2 $<
-	$(BASERUBY) -pli -e '$$_.sub!(/[ \t]+$$/, "")' \
-	-e '$$_.sub!(/^static const int (JSON_.*=.*);$$/, "enum {\\1};")' $@
-
-parser.c:
diff --git a/test/json/fixtures/fail1.json b/test/json/fixtures/fail1.json
deleted file mode 100644
index 6216b865f1..0000000000
--- a/test/json/fixtures/fail1.json
+++ /dev/null
@@ -1 +0,0 @@
-"A JSON payload should be an object or array, not a string."
\ No newline at end of file
diff --git a/test/json/fixtures/obsolete_fail1.json b/test/json/fixtures/obsolete_fail1.json
new file mode 100644
index 0000000000..98b77de6a8
--- /dev/null
+++ b/test/json/fixtures/obsolete_fail1.json
@@ -0,0 +1 @@
+"A JSON payload should be an object or array, not a string."
diff --git a/test/json/setup_variant.rb b/test/json/test_helper.rb
index f7fb2a1d56..69edb627e8 100644
--- a/test/json/setup_variant.rb
+++ b/test/json/test_helper.rb
@@ -10,3 +10,13 @@ else
   $:.unshift 'ext', 'lib'
   require 'json'
 end
+
+require 'test/unit'
+begin
+  require 'byebug'
+rescue LoadError
+end
+if ENV['START_SIMPLECOV'].to_i == 1
+  require 'simplecov'
+  SimpleCov.start
+end
diff --git a/test/json/test_json.rb b/test/json/test_json.rb
deleted file mode 100755
index 8fe9459978..0000000000
--- a/test/json/test_json.rb
+++ /dev/null
@@ -1,577 +0,0 @@
-#!/usr/bin/env ruby
-# encoding: utf-8
-# frozen_string_literal: false
-
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
-require 'stringio'
-require 'tempfile'
-require 'ostruct'
-
-unless Array.method_defined?(:permutation)
-  begin
-    require 'enumerator'
-    require 'permutation'
-    class Array
-      def permutation
-        Permutation.for(self).to_enum.map { |x| x.project }
-      end
-    end
-  rescue LoadError
-    warn "Skipping permutation tests."
-  end
-end
-
-class TestJSON < Test::Unit::TestCase
-  include JSON
-
-  def setup
-    @ary = [1, "foo", 3.14, 4711.0, 2.718, nil, [1,-2,3], false, true].map do
-      |x| [x]
-    end
-    @ary_to_parse = ["1", '"foo"', "3.14", "4711.0", "2.718", "null",
-      "[1,-2,3]", "false", "true"].map do
-      |x| "[#{x}]"
-    end
-    @hash = {
-      'a' => 2,
-      'b' => 3.141,
-      'c' => 'c',
-      'd' => [ 1, "b", 3.14 ],
-      'e' => { 'foo' => 'bar' },
-      'g' => "\"\0\037",
-      'h' => 1000.0,
-      'i' => 0.001
-    }
-    @json = '{"a":2,"b":3.141,"c":"c","d":[1,"b",3.14],"e":{"foo":"bar"},'\
-      '"g":"\\"\\u0000\\u001f","h":1.0E3,"i":1.0E-3}'
-  end
-
-  def test_construction
-    parser = JSON::Parser.new('test')
-    assert_equal 'test', parser.source
-  end
-
-  def assert_equal_float(expected, is)
-    assert_in_delta(expected.first, is.first, 1e-2)
-  end
-
-  def test_parse_simple_arrays
-    assert_equal([], parse('[]'))
-    assert_equal([], parse('  [  ] '))
-    assert_equal([nil], parse('[null]'))
-    assert_equal([false], parse('[false]'))
-    assert_equal([true], parse('[true]'))
-    assert_equal([-23], parse('[-23]'))
-    assert_equal([23], parse('[23]'))
-    assert_equal([0.23], parse('[0.23]'))
-    assert_equal([0.0], parse('[0e0]'))
-    assert_raise(JSON::ParserError) { parse('[+23.2]') }
-    assert_raise(JSON::ParserError) { parse('[+23]') }
-    assert_raise(JSON::ParserError) { parse('[.23]') }
-    assert_raise(JSON::ParserError) { parse('[023]') }
-    assert_equal_float [3.141], parse('[3.141]')
-    assert_equal_float [-3.141], parse('[-3.141]')
-    assert_equal_float [3.141], parse('[3141e-3]')
-    assert_equal_float [3.141], parse('[3141.1e-3]')
-    assert_equal_float [3.141], parse('[3141E-3]')
-    assert_equal_float [3.141], parse('[3141.0E-3]')
-    assert_equal_float [-3.141], parse('[-3141.0e-3]')
-    assert_equal_float [-3.141], parse('[-3141e-3]')
-    assert_raise(ParserError) { parse('[NaN]') }
-    assert parse('[NaN]', :allow_nan => true).first.nan?
-    assert_raise(ParserError) { parse('[Infinity]') }
-    assert_equal [1.0/0], parse('[Infinity]', :allow_nan => true)
-    assert_raise(ParserError) { parse('[-Infinity]') }
-    assert_equal [-1.0/0], parse('[-Infinity]', :allow_nan => true)
-    assert_equal([""], parse('[""]'))
-    assert_equal(["foobar"], parse('["foobar"]'))
-    assert_equal([{}], parse('[{}]'))
-  end
-
-  def test_parse_simple_objects
-    assert_equal({}, parse('{}'))
-    assert_equal({}, parse(' {   }   '))
-    assert_equal({ "a" => nil }, parse('{   "a"   :  null}'))
-    assert_equal({ "a" => nil }, parse('{"a":null}'))
-    assert_equal({ "a" => false }, parse('{   "a"  :  false  }  '))
-    assert_equal({ "a" => false }, parse('{"a":false}'))
-    assert_raise(JSON::ParserError) { parse('{false}') }
-    assert_equal({ "a" => true }, parse('{"a":true}'))
-    assert_equal({ "a" => true }, parse('  { "a" :  true  }   '))
-    assert_equal({ "a" => -23 }, parse('  {  "a"  :  -23  }  '))
-    assert_equal({ "a" => -23 }, parse('  { "a" : -23 } '))
-    assert_equal({ "a" => 23 }, parse('{"a":23  } '))
-    assert_equal({ "a" => 23 }, parse('  { "a"  : 23  } '))
-    assert_equal({ "a" => 0.23 }, parse(' { "a"  :  0.23 }  '))
-    assert_equal({ "a" => 0.23 }, parse('  {  "a"  :  0.23  }  '))
-  end
-
-  def test_parse_json_primitive_values
-    assert_raise(JSON::ParserError) { JSON.parse('') }
-    assert_raise(JSON::ParserError) { JSON.parse('', :quirks_mode => true) }
-    assert_raise(TypeError) { JSON::Parser.new(nil).parse }
-    assert_raise(TypeError) { JSON::Parser.new(nil, :quirks_mode => true).parse }
-    assert_raise(TypeError) { JSON.parse(nil) }
-    assert_raise(TypeError) { JSON.parse(nil, :quirks_mode => true) }
-    assert_raise(JSON::ParserError) { JSON.parse('  /* foo */ ') }
-    assert_raise(JSON::ParserError) { JSON.parse('  /* foo */ ', :quirks_mode => true) }
-    parser = JSON::Parser.new('null')
-    assert_equal false, parser.quirks_mode?
-    assert_raise(JSON::ParserError) { parser.parse }
-    assert_raise(JSON::ParserError) { JSON.parse('null') }
-    assert_equal nil, JSON.parse('null', :quirks_mode => true)
-    parser = JSON::Parser.new('null', :quirks_mode => true)
-    assert_equal true, parser.quirks_mode?
-    assert_equal nil, parser.parse
-    assert_raise(JSON::ParserError) { JSON.parse('false') }
-    assert_equal false, JSON.parse('false', :quirks_mode => true)
-    assert_raise(JSON::ParserError) { JSON.parse('true') }
-    assert_equal true, JSON.parse('true', :quirks_mode => true)
-    assert_raise(JSON::ParserError) { JSON.parse('23') }
-    assert_equal 23, JSON.parse('23', :quirks_mode => true)
-    assert_raise(JSON::ParserError) { JSON.parse('1') }
-    assert_equal 1, JSON.parse('1', :quirks_mode => true)
-    assert_raise(JSON::ParserError) { JSON.parse('3.141') }
-    assert_in_delta 3.141, JSON.parse('3.141', :quirks_mode => true), 1E-3
-    assert_raise(JSON::ParserError) { JSON.parse('18446744073709551616') }
-    assert_equal 2 ** 64, JSON.parse('18446744073709551616', :quirks_mode => true)
-    assert_raise(JSON::ParserError) { JSON.parse('"foo"') }
-    assert_equal 'foo', JSON.parse('"foo"', :quirks_mode => true)
-    assert_raise(JSON::ParserError) { JSON.parse('NaN', :allow_nan => true) }
-    assert JSON.parse('NaN', :quirks_mode => true, :allow_nan => true).nan?
-    assert_raise(JSON::ParserError) { JSON.parse('Infinity', :allow_nan => true) }
-    assert JSON.parse('Infinity', :quirks_mode => true, :allow_nan => true).infinite?
-    assert_raise(JSON::ParserError) { JSON.parse('-Infinity', :allow_nan => true) }
-    assert JSON.parse('-Infinity', :quirks_mode => true, :allow_nan => true).infinite?
-    assert_raise(JSON::ParserError) { JSON.parse('[ 1, ]', :quirks_mode => true) }
-  end
-
-  if Array.method_defined?(:permutation)
-    def test_parse_more_complex_arrays
-      a = [ nil, false, true, "foßbar", [ "n€st€d", true ], { "nested" => true, "n€ßt€ð2" => {} }]
-      a.permutation.each do |perm|
-        json = pretty_generate(perm)
-        assert_equal perm, parse(json)
-      end
-    end
-
-    def test_parse_complex_objects
-      a = [ nil, false, true, "foßbar", [ "n€st€d", true ], { "nested" => true, "n€ßt€ð2" => {} }]
-      a.permutation.each do |perm|
-        s = "a"
-        orig_obj = perm.inject({}) { |h, x| h[s.dup] = x; s = s.succ; h }
-        json = pretty_generate(orig_obj)
-        assert_equal orig_obj, parse(json)
-      end
-    end
-  end
-
-  def test_parse_arrays
-    assert_equal([1,2,3], parse('[1,2,3]'))
-    assert_equal([1.2,2,3], parse('[1.2,2,3]'))
-    assert_equal([[],[[],[]]], parse('[[],[[],[]]]'))
-  end
-
-  def test_parse_values
-    assert_equal([""], parse('[""]'))
-    assert_equal(["\\"], parse('["\\\\"]'))
-    assert_equal(['"'], parse('["\""]'))
-    assert_equal(['\\"\\'], parse('["\\\\\\"\\\\"]'))
-    assert_equal(["\"\b\n\r\t\0\037"],
-      parse('["\"\b\n\r\t\u0000\u001f"]'))
-    for i in 0 ... @ary.size
-      assert_equal(@ary[i], parse(@ary_to_parse[i]))
-    end
-  end
-
-  def test_parse_array
-    assert_equal([], parse('[]'))
-    assert_equal([], parse('  [  ]  '))
-    assert_equal([1], parse('[1]'))
-    assert_equal([1], parse('  [ 1  ]  '))
-    assert_equal(@ary,
-      parse('[[1],["foo"],[3.14],[47.11e+2],[2718.0E-3],[null],[[1,-2,3]]'\
-      ',[false],[true]]'))
-    assert_equal(@ary, parse(%Q{   [   [1] , ["foo"]  ,  [3.14] \t ,  [47.11e+2]\s
-      , [2718.0E-3 ],\r[ null] , [[1, -2, 3 ]], [false ],[ true]\n ]  }))
-  end
-
-  class SubArray < Array
-    def <<(v)
-      @shifted = true
-      super
-    end
-
-    def shifted?
-      @shifted
-    end
-  end
-
-  class SubArray2 < Array
-    def to_json(*a)
-      {
-        JSON.create_id => self.class.name,
-        'ary'          => to_a,
-      }.to_json(*a)
-    end
-
-    def self.json_create(o)
-      o.delete JSON.create_id
-      o['ary']
-    end
-  end
-
-  class SubArrayWrapper
-    def initialize
-      @data = []
-    end
-
-    attr_reader :data
-
-    def [](index)
-      @data[index]
-    end
-
-    def <<(value)
-      @data << value
-      @shifted = true
-    end
-
-    def shifted?
-      @shifted
-    end
-  end
-
-  def test_parse_array_custom_array_derived_class
-    res = parse('[1,2]', :array_class => SubArray)
-    assert_equal([1,2], res)
-    assert_equal(SubArray, res.class)
-    assert res.shifted?
-  end
-
-  def test_parse_array_custom_non_array_derived_class
-    res = parse('[1,2]', :array_class => SubArrayWrapper)
-    assert_equal([1,2], res.data)
-    assert_equal(SubArrayWrapper, res.class)
-    assert res.shifted?
-  end
-
-  def test_parse_object
-    assert_equal({}, parse('{}'))
-    assert_equal({}, parse('  {  }  '))
-    assert_equal({'foo'=>'bar'}, parse('{"foo":"bar"}'))
-    assert_equal({'foo'=>'bar'}, parse('    { "foo"  :   "bar"   }   '))
-  end
-
-  class SubHash < Hash
-    def []=(k, v)
-      @item_set = true
-      super
-    end
-
-    def item_set?
-      @item_set
-    end
-  end
-
-  class SubHash2 < Hash
-    def to_json(*a)
-      {
-        JSON.create_id => self.class.name,
-      }.merge(self).to_json(*a)
-    end
-
-    def self.json_create(o)
-      o.delete JSON.create_id
-      self[o]
-    end
-  end
-
-  class SubOpenStruct < OpenStruct
-    def [](k)
-      __send__(k)
-    end
-
-    def []=(k, v)
-      @item_set = true
-      __send__("#{k}=", v)
-    end
-
-    def item_set?
-      @item_set
-    end
-  end
-
-  def test_parse_object_custom_hash_derived_class
-    res = parse('{"foo":"bar"}', :object_class => SubHash)
-    assert_equal({"foo" => "bar"}, res)
-    assert_equal(SubHash, res.class)
-    assert res.item_set?
-  end
-
-  def test_parse_object_custom_non_hash_derived_class
-    res = parse('{"foo":"bar"}', :object_class => SubOpenStruct)
-    assert_equal "bar", res.foo
-    assert_equal(SubOpenStruct, res.class)
-    assert res.item_set?
-  end
-
-  def test_parse_generic_object
-    res = parse('{"foo":"bar", "baz":{}}', :object_class => JSON::GenericObject)
-    assert_equal(JSON::GenericObject, res.class)
-    assert_equal "bar", res.foo
-    assert_equal "bar", res["foo"]
-    assert_equal "bar", res[:foo]
-    assert_equal "bar", res.to_hash[:foo]
-    assert_equal(JSON::GenericObject, res.baz.class)
-  end
-
-  def test_generate_core_subclasses_with_new_to_json
-    obj = SubHash2["foo" => SubHash2["bar" => true]]
-    obj_json = JSON(obj)
-    obj_again = JSON.parse(obj_json, :create_additions => true)
-    assert_kind_of SubHash2, obj_again
-    assert_kind_of SubHash2, obj_again['foo']
-    assert obj_again['foo']['bar']
-    assert_equal obj, obj_again
-    assert_equal ["foo"], JSON(JSON(SubArray2["foo"]), :create_additions => true)
-  end
-
-  def test_generate_core_subclasses_with_default_to_json
-    assert_equal '{"foo":"bar"}', JSON(SubHash["foo" => "bar"])
-    assert_equal '["foo"]', JSON(SubArray["foo"])
-  end
-
-  def test_generate_of_core_subclasses
-    obj = SubHash["foo" => SubHash["bar" => true]]
-    obj_json = JSON(obj)
-    obj_again = JSON(obj_json)
-    assert_kind_of Hash, obj_again
-    assert_kind_of Hash, obj_again['foo']
-    assert obj_again['foo']['bar']
-    assert_equal obj, obj_again
-  end
-
-  def test_parser_reset
-    parser = Parser.new(@json)
-    assert_equal(@hash, parser.parse)
-    assert_equal(@hash, parser.parse)
-  end
-
-  def test_comments
-    json = <<EOT
-{
-  "key1":"value1", // eol comment
-  "key2":"value2"  /* multi line
-                    *  comment */,
-  "key3":"value3"  /* multi line
-                    // nested eol comment
-                    *  comment */
-}
-EOT
-    assert_equal(
-      { "key1" => "value1", "key2" => "value2", "key3" => "value3" },
-      parse(json))
-    json = <<EOT
-{
-  "key1":"value1"  /* multi line
-                    // nested eol comment
-                    /* illegal nested multi line comment */
-                    *  comment */
-}
-EOT
-    assert_raise(ParserError) { parse(json) }
-    json = <<EOT
-{
-  "key1":"value1"  /* multi line
-                   // nested eol comment
-                   closed multi comment */
-                   and again, throw an Error */
-}
-EOT
-    assert_raise(ParserError) { parse(json) }
-    json = <<EOT
-{
-  "key1":"value1"  /*/*/
-}
-EOT
-    assert_equal({ "key1" => "value1" }, parse(json))
-  end
-
-  def test_backslash
-    data = [ '\\.(?i:gif|jpe?g|png)$' ]
-    json = '["\\\\.(?i:gif|jpe?g|png)$"]'
-    assert_equal json, JSON.generate(data)
-    assert_equal data, JSON.parse(json)
-    #
-    data = [ '\\"' ]
-    json = '["\\\\\""]'
-    assert_equal json, JSON.generate(data)
-    assert_equal data, JSON.parse(json)
-    #
-    json = '["/"]'
-    data = JSON.parse(json)
-    assert_equal ['/'], data
-    assert_equal json, JSON.generate(data)
-    #
-    json = '["\""]'
-    data = JSON.parse(json)
-    assert_equal ['"'], data
-    assert_equal json, JSON.generate(data)
-    json = '["\\\'"]'
-    data = JSON.parse(json)
-    assert_equal ["'"], data
-    assert_equal '["\'"]', JSON.generate(data)
-  end
-
-  def test_wrong_inputs
-    assert_raise(ParserError) { JSON.parse('"foo"') }
-    assert_raise(ParserError) { JSON.parse('123') }
-    assert_raise(ParserError) { JSON.parse('[] bla') }
-    assert_raise(ParserError) { JSON.parse('[] 1') }
-    assert_raise(ParserError) { JSON.parse('[] []') }
-    assert_raise(ParserError) { JSON.parse('[] {}') }
-    assert_raise(ParserError) { JSON.parse('{} []') }
-    assert_raise(ParserError) { JSON.parse('{} {}') }
-    assert_raise(ParserError) { JSON.parse('[NULL]') }
-    assert_raise(ParserError) { JSON.parse('[FALSE]') }
-    assert_raise(ParserError) { JSON.parse('[TRUE]') }
-    assert_raise(ParserError) { JSON.parse('[07]    ') }
-    assert_raise(ParserError) { JSON.parse('[0a]') }
-    assert_raise(ParserError) { JSON.parse('[1.]') }
-    assert_raise(ParserError) { JSON.parse('     ') }
-  end
-
-  def test_nesting
-    assert_raise(JSON::NestingError) { JSON.parse '[[]]', :max_nesting => 1 }
-    assert_raise(JSON::NestingError) { JSON.parser.new('[[]]', :max_nesting => 1).parse }
-    assert_equal [[]], JSON.parse('[[]]', :max_nesting => 2)
-    too_deep = '[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]'
-    too_deep_ary = eval too_deep
-    assert_raise(JSON::NestingError) { JSON.parse too_deep }
-    assert_raise(JSON::NestingError) { JSON.parser.new(too_deep).parse }
-    assert_raise(JSON::NestingError) { JSON.parse too_deep, :max_nesting => 100 }
-    ok = JSON.parse too_deep, :max_nesting => 101
-    assert_equal too_deep_ary, ok
-    ok = JSON.parse too_deep, :max_nesting => nil
-    assert_equal too_deep_ary, ok
-    ok = JSON.parse too_deep, :max_nesting => false
-    assert_equal too_deep_ary, ok
-    ok = JSON.parse too_deep, :max_nesting => 0
-    assert_equal too_deep_ary, ok
-    assert_raise(JSON::NestingError) { JSON.generate [[]], :max_nesting => 1 }
-    assert_equal '[[]]', JSON.generate([[]], :max_nesting => 2)
-    assert_raise(JSON::NestingError) { JSON.generate too_deep_ary }
-    assert_raise(JSON::NestingError) { JSON.generate too_deep_ary, :max_nesting => 100 }
-    ok = JSON.generate too_deep_ary, :max_nesting => 101
-    assert_equal too_deep, ok
-    ok = JSON.generate too_deep_ary, :max_nesting => nil
-    assert_equal too_deep, ok
-    ok = JSON.generate too_deep_ary, :max_nesting => false
-    assert_equal too_deep, ok
-    ok = JSON.generate too_deep_ary, :max_nesting => 0
-    assert_equal too_deep, ok
-  end
-
-  def test_symbolize_names
-    assert_equal({ "foo" => "bar", "baz" => "quux" },
-      JSON.parse('{"foo":"bar", "baz":"quux"}'))
-    assert_equal({ :foo => "bar", :baz => "quux" },
-      JSON.parse('{"foo":"bar", "baz":"quux"}', :symbolize_names => true))
-  end
-
-  def test_load
-    assert_equal @hash, JSON.load(@json)
-    tempfile = Tempfile.open('json')
-    tempfile.write @json
-    tempfile.rewind
-    assert_equal @hash, JSON.load(tempfile)
-    stringio = StringIO.new(@json)
-    stringio.rewind
-    assert_equal @hash, JSON.load(stringio)
-    assert_equal nil, JSON.load(nil)
-    assert_equal nil, JSON.load('')
-  ensure
-    tempfile.close!
-  end
-
-  def test_load_with_options
-    small_hash  = JSON("foo" => 'bar')
-    symbol_hash = { :foo => 'bar' }
-    assert_equal symbol_hash, JSON.load(small_hash, nil, :symbolize_names => true)
-  end
-
-  def test_dump
-    too_deep = '[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]'
-    assert_equal too_deep, JSON.dump(eval(too_deep))
-    assert_kind_of String, Marshal.dump(eval(too_deep))
-    assert_raise(ArgumentError) { JSON.dump(eval(too_deep), 100) }
-    assert_raise(ArgumentError) { Marshal.dump(eval(too_deep), 100) }
-    assert_equal too_deep, JSON.dump(eval(too_deep), 101)
-    assert_kind_of String, Marshal.dump(eval(too_deep), 101)
-    output = StringIO.new
-    JSON.dump(eval(too_deep), output)
-    assert_equal too_deep, output.string
-    output = StringIO.new
-    JSON.dump(eval(too_deep), output, 101)
-    assert_equal too_deep, output.string
-  end
-
-  def test_dump_should_modify_defaults
-    max_nesting = JSON.dump_default_options[:max_nesting]
-    JSON.dump([], StringIO.new, 10)
-    assert_equal max_nesting, JSON.dump_default_options[:max_nesting]
-  end
-
-  def test_big_integers
-    json1 = JSON([orig = (1 << 31) - 1])
-    assert_equal orig, JSON[json1][0]
-    json2 = JSON([orig = 1 << 31])
-    assert_equal orig, JSON[json2][0]
-    json3 = JSON([orig = (1 << 62) - 1])
-    assert_equal orig, JSON[json3][0]
-    json4 = JSON([orig = 1 << 62])
-    assert_equal orig, JSON[json4][0]
-    json5 = JSON([orig = 1 << 64])
-    assert_equal orig, JSON[json5][0]
-  end
-
-  if defined?(JSON::Ext::Parser)
-    def test_allocate
-      parser = JSON::Ext::Parser.new("{}")
-      assert_raise(TypeError, '[ruby-core:35079]') {parser.__send__(:initialize, "{}")}
-      parser = JSON::Ext::Parser.allocate
-      assert_raise(TypeError, '[ruby-core:35079]') {parser.source}
-    end
-  end
-
-  def test_argument_encoding
-    source = "{}".force_encoding("ascii-8bit")
-    JSON::Parser.new(source)
-    assert_equal Encoding::ASCII_8BIT, source.encoding
-  end if defined?(Encoding::ASCII_8BIT)
-
-  def test_error_message_encoding
-    bug10705 = '[ruby-core:67386] [Bug #10705]'
-    json = "\"\xE2\x88\x9A\"".force_encoding(Encoding::UTF_8)
-    e = assert_raise(JSON::ParserError) {
-      JSON.parse(json)
-    }
-    assert_equal(Encoding::UTF_8, e.message.encoding, bug10705)
-    assert_include(e.message, json, bug10705)
-  end if defined?(Encoding::UTF_8)
-
-  if EnvUtil.gc_stress_to_class?
-    def assert_no_memory_leak(code, *rest, **opt)
-      code = "8.times {20_000.times {begin #{code}; rescue NoMemoryError; end}; GC.start}"
-      super(["-rjson/ext/parser"],
-            "GC.add_stress_to_class(JSON::Ext::Parser); "\
-            "#{code}", code, *rest, rss: true, limit: 1.1, **opt)
-    end
-
-    def test_no_memory_leak_allocate
-      assert_no_memory_leak("JSON::Ext::Parser.allocate")
-    end
-  end
-end
diff --git a/test/json/test_json_addition.rb b/test/json/test_json_addition.rb
index f2059312de..7a49d62d73 100644
--- a/test/json/test_json_addition.rb
+++ b/test/json/test_json_addition.rb
@@ -1,9 +1,5 @@
-#!/usr/bin/env ruby
-# -*- coding:utf-8 -*-
 # frozen_string_literal: false
-
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
+require 'test_helper'
 require 'json/add/core'
 require 'json/add/complex'
 require 'json/add/rational'
@@ -74,7 +70,7 @@ class TestJSONAddition < Test::Unit::TestCase
     a = A.new(666)
     assert A.json_creatable?
     json = generate(a)
-    a_again = JSON.parse(json, :create_additions => true)
+    a_again = parse(json, :create_additions => true)
     assert_kind_of a.class, a_again
     assert_equal a, a_again
   end
@@ -83,7 +79,7 @@ class TestJSONAddition < Test::Unit::TestCase
     a = A.new(666)
     assert A.json_creatable?
     json = generate(a)
-    a_hash = JSON.parse(json)
+    a_hash = parse(json)
     assert_kind_of Hash, a_hash
   end
 
@@ -91,10 +87,10 @@ class TestJSONAddition < Test::Unit::TestCase
     a = A.new(666)
     assert A.json_creatable?
     json = generate(a)
-    a_again = JSON.parse(json, :create_additions => true)
+    a_again = parse(json, :create_additions => true)
     assert_kind_of a.class, a_again
     assert_equal a, a_again
-    a_hash = JSON.parse(json, :create_additions => false)
+    a_hash = parse(json, :create_additions => false)
     assert_kind_of Hash, a_hash
     assert_equal(
       {"args"=>[666], "json_class"=>"TestJSONAddition::A"}.sort_by { |k,| k },
@@ -106,14 +102,14 @@ class TestJSONAddition < Test::Unit::TestCase
     b = B.new
     assert !B.json_creatable?
     json = generate(b)
-    assert_equal({ "json_class"=>"TestJSONAddition::B" }, JSON.parse(json))
+    assert_equal({ "json_class"=>"TestJSONAddition::B" }, parse(json))
   end
 
   def test_extended_json_fail2
     c = C.new
     assert !C.json_creatable?
     json = generate(c)
-    assert_raise(ArgumentError, NameError) { JSON.parse(json, :create_additions => true) }
+    assert_raise(ArgumentError, NameError) { parse(json, :create_additions => true) }
   end
 
   def test_raw_strings
@@ -131,7 +127,7 @@ class TestJSONAddition < Test::Unit::TestCase
     assert_match(/\A\{.*\}\z/, json)
     assert_match(/"json_class":"String"/, json)
     assert_match(/"raw":\[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255\]/, json)
-    raw_again = JSON.parse(json, :create_additions => true)
+    raw_again = parse(json, :create_additions => true)
     assert_equal raw, raw_again
   end
 
@@ -168,19 +164,19 @@ class TestJSONAddition < Test::Unit::TestCase
 
   def test_utc_datetime
     now = Time.now
-    d = DateTime.parse(now.to_s, :create_additions => true)                    # usual case
-    assert_equal d, JSON.parse(d.to_json, :create_additions => true)
-    d = DateTime.parse(now.utc.to_s)                # of = 0
-    assert_equal d, JSON.parse(d.to_json, :create_additions => true)
+    d = DateTime.parse(now.to_s, :create_additions => true) # usual case
+    assert_equal d, parse(d.to_json, :create_additions => true)
+    d = DateTime.parse(now.utc.to_s) # of = 0
+    assert_equal d, parse(d.to_json, :create_additions => true)
     d = DateTime.civil(2008, 6, 17, 11, 48, 32, Rational(1,24))
-    assert_equal d, JSON.parse(d.to_json, :create_additions => true)
+    assert_equal d, parse(d.to_json, :create_additions => true)
     d = DateTime.civil(2008, 6, 17, 11, 48, 32, Rational(12,24))
-    assert_equal d, JSON.parse(d.to_json, :create_additions => true)
+    assert_equal d, parse(d.to_json, :create_additions => true)
   end
 
   def test_rational_complex
-    assert_equal Rational(2, 9), JSON.parse(JSON(Rational(2, 9)), :create_additions => true)
-    assert_equal Complex(2, 9), JSON.parse(JSON(Complex(2, 9)), :create_additions => true)
+    assert_equal Rational(2, 9), parse(JSON(Rational(2, 9)), :create_additions => true)
+    assert_equal Complex(2, 9), parse(JSON(Complex(2, 9)), :create_additions => true)
   end
 
   def test_bigdecimal
@@ -192,6 +188,6 @@ class TestJSONAddition < Test::Unit::TestCase
     o = OpenStruct.new
     # XXX this won't work; o.foo = { :bar => true }
     o.foo = { 'bar' => true }
-    assert_equal o, JSON.parse(JSON(o), :create_additions => true)
+    assert_equal o, parse(JSON(o), :create_additions => true)
   end
 end
diff --git a/test/json/test_json_common_interface.rb b/test/json/test_json_common_interface.rb
new file mode 100644
index 0000000000..3b222b35e0
--- /dev/null
+++ b/test/json/test_json_common_interface.rb
@@ -0,0 +1,126 @@
+# frozen_string_literal: false
+require 'test_helper'
+require 'stringio'
+require 'tempfile'
+
+class TestJSONCommonInterface < Test::Unit::TestCase
+  include JSON
+
+  def setup
+    @hash = {
+      'a' => 2,
+      'b' => 3.141,
+      'c' => 'c',
+      'd' => [ 1, "b", 3.14 ],
+      'e' => { 'foo' => 'bar' },
+      'g' => "\"\0\037",
+      'h' => 1000.0,
+      'i' => 0.001
+    }
+    @json = '{"a":2,"b":3.141,"c":"c","d":[1,"b",3.14],"e":{"foo":"bar"},'\
+      '"g":"\\"\\u0000\\u001f","h":1000.0,"i":0.001}'
+  end
+
+  def test_index
+    assert_equal @json, JSON[@hash]
+    assert_equal @hash, JSON[@json]
+  end
+
+  def test_parser
+    assert_match /::Parser\z/, JSON.parser.name
+  end
+
+  def test_generator
+    assert_match /::Generator\z/, JSON.generator.name
+  end
+
+  def test_state
+    assert_match /::Generator::State\z/, JSON.state.name
+  end
+
+  def test_create_id
+    assert_equal 'json_class', JSON.create_id
+    JSON.create_id = 'foo_bar'
+    assert_equal 'foo_bar', JSON.create_id
+  ensure
+    JSON.create_id = 'json_class'
+  end
+
+  def test_deep_const_get
+    assert_raise(ArgumentError) { JSON.deep_const_get('Nix::Da') }
+    assert_equal File::SEPARATOR, JSON.deep_const_get('File::SEPARATOR')
+  end
+
+  def test_parse
+    assert_equal [ 1, 2, 3, ], JSON.parse('[ 1, 2, 3 ]')
+  end
+
+  def test_parse_bang
+    assert_equal [ 1, NaN, 3, ], JSON.parse!('[ 1, NaN, 3 ]')
+  end
+
+  def test_generate
+    assert_equal '[1,2,3]', JSON.generate([ 1, 2, 3 ])
+  end
+
+  def test_fast_generate
+    assert_equal '[1,2,3]', JSON.generate([ 1, 2, 3 ])
+  end
+
+  def test_pretty_generate
+    assert_equal "[\n  1,\n  2,\n  3\n]", JSON.pretty_generate([ 1, 2, 3 ])
+  end
+
+  def test_load
+    assert_equal @hash, JSON.load(@json)
+    tempfile = Tempfile.open('@json')
+    tempfile.write @json
+    tempfile.rewind
+    assert_equal @hash, JSON.load(tempfile)
+    stringio = StringIO.new(@json)
+    stringio.rewind
+    assert_equal @hash, JSON.load(stringio)
+    assert_equal nil, JSON.load(nil)
+    assert_equal nil, JSON.load('')
+  ensure
+    tempfile.close!
+  end
+
+  def test_load_with_options
+    json  = '{ "foo": NaN }'
+    assert JSON.load(json, nil, :allow_nan => true)['foo'].nan?
+  end
+
+  def test_load_null
+    assert_equal nil, JSON.load(nil, nil, :allow_blank => true)
+    assert_raise(TypeError) { JSON.load(nil, nil, :allow_blank => false) }
+    assert_raise(JSON::ParserError) { JSON.load('', nil, :allow_blank => false) }
+  end
+
+  def test_dump
+    too_deep = '[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]'
+    assert_equal too_deep, dump(eval(too_deep))
+    assert_kind_of String, Marshal.dump(eval(too_deep))
+    assert_raise(ArgumentError) { dump(eval(too_deep), 100) }
+    assert_raise(ArgumentError) { Marshal.dump(eval(too_deep), 100) }
+    assert_equal too_deep, dump(eval(too_deep), 101)
+    assert_kind_of String, Marshal.dump(eval(too_deep), 101)
+    output = StringIO.new
+    dump(eval(too_deep), output)
+    assert_equal too_deep, output.string
+    output = StringIO.new
+    dump(eval(too_deep), output, 101)
+    assert_equal too_deep, output.string
+  end
+
+  def test_dump_should_modify_defaults
+    max_nesting = JSON.dump_default_options[:max_nesting]
+    dump([], StringIO.new, 10)
+    assert_equal max_nesting, JSON.dump_default_options[:max_nesting]
+  end
+
+  def test_JSON
+    assert_equal @json, JSON(@hash)
+    assert_equal @hash, JSON(@json)
+  end
+end
diff --git a/test/json/test_json_encoding.rb b/test/json/test_json_encoding.rb
index 50fb4ea279..ede6402842 100644
--- a/test/json/test_json_encoding.rb
+++ b/test/json/test_json_encoding.rb
@@ -1,44 +1,33 @@
-#!/usr/bin/env ruby
 # encoding: utf-8
 # frozen_string_literal: false
-
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
+require 'test_helper'
 
 class TestJSONEncoding < Test::Unit::TestCase
   include JSON
 
   def setup
-    @utf_8 = '["© ≠ €!"]'
-    @parsed = [ "© ≠ €!" ]
-    @generated = '["\u00a9 \u2260 \u20ac!"]'
+    @utf_8      = '"© ≠ €!"'
+    @ascii_8bit = @utf_8.dup.force_encoding('ascii-8bit')
+    @parsed     = "© ≠ €!"
+    @generated  = '"\u00a9 \u2260 \u20ac!"'
     if String.method_defined?(:encode)
-      @utf_16_data = [@parsed.first.encode('utf-16be', 'utf-8')]
-      @utf_8_ascii_8bit = @utf_8.dup.force_encoding(Encoding::ASCII_8BIT)
+      @utf_16_data = @parsed.encode('utf-16be', 'utf-8')
       @utf_16be = @utf_8.encode('utf-16be', 'utf-8')
-      @utf_16be_ascii_8bit = @utf_16be.dup.force_encoding(Encoding::ASCII_8BIT)
       @utf_16le = @utf_8.encode('utf-16le', 'utf-8')
-      @utf_16le_ascii_8bit = @utf_16le.dup.force_encoding(Encoding::ASCII_8BIT)
       @utf_32be = @utf_8.encode('utf-32be', 'utf-8')
-      @utf_32be_ascii_8bit = @utf_32be.dup.force_encoding(Encoding::ASCII_8BIT)
       @utf_32le = @utf_8.encode('utf-32le', 'utf-8')
-      @utf_32le_ascii_8bit = @utf_32le.dup.force_encoding(Encoding::ASCII_8BIT)
     else
       require 'iconv'
-      @utf_16_data = Iconv.iconv('utf-16be', 'utf-8', @parsed.first)
-      @utf_8_ascii_8bit = @utf_8.dup
+      @utf_16_data, = Iconv.iconv('utf-16be', 'utf-8', @parsed)
       @utf_16be, = Iconv.iconv('utf-16be', 'utf-8', @utf_8)
-      @utf_16be_ascii_8bit = @utf_16be.dup
       @utf_16le, = Iconv.iconv('utf-16le', 'utf-8', @utf_8)
-      @utf_16le_ascii_8bit = @utf_16le.dup
       @utf_32be, = Iconv.iconv('utf-32be', 'utf-8', @utf_8)
-      @utf_32be_ascii_8bit = @utf_32be.dup
       @utf_32le, = Iconv.iconv('utf-32le', 'utf-8', @utf_8)
-      @utf_32le_ascii_8bit = @utf_32le.dup
     end
   end
 
   def test_parse
+    assert_equal @parsed, JSON.parse(@ascii_8bit)
     assert_equal @parsed, JSON.parse(@utf_8)
     assert_equal @parsed, JSON.parse(@utf_16be)
     assert_equal @parsed, JSON.parse(@utf_16le)
@@ -46,21 +35,71 @@ class TestJSONEncoding < Test::Unit::TestCase
     assert_equal @parsed, JSON.parse(@utf_32le)
   end
 
-  def test_parse_ascii_8bit
-    assert_equal @parsed, JSON.parse(@utf_8_ascii_8bit)
-    assert_equal @parsed, JSON.parse(@utf_16be_ascii_8bit)
-    assert_equal @parsed, JSON.parse(@utf_16le_ascii_8bit)
-    assert_equal @parsed, JSON.parse(@utf_32be_ascii_8bit)
-    assert_equal @parsed, JSON.parse(@utf_32le_ascii_8bit)
-  end
-
   def test_generate
     assert_equal @generated, JSON.generate(@parsed, :ascii_only => true)
-    if defined?(::Encoding)
-      assert_equal @generated, JSON.generate(@utf_16_data, :ascii_only => true)
-    else
-      # XXX checking of correct utf8 data is not as strict (yet?) without :ascii_only
-      assert_raise(JSON::GeneratorError) { JSON.generate(@utf_16_data, :ascii_only => true) }
+    assert_equal @generated, JSON.generate(@utf_16_data, :ascii_only => true)
+  end
+
+  def test_unicode
+    assert_equal '""', ''.to_json
+    assert_equal '"\\b"', "\b".to_json
+    assert_equal '"\u0001"', 0x1.chr.to_json
+    assert_equal '"\u001f"', 0x1f.chr.to_json
+    assert_equal '" "', ' '.to_json
+    assert_equal "\"#{0x7f.chr}\"", 0x7f.chr.to_json
+    utf8 = [ "© ≠ €! \01" ]
+    json = '["© ≠ €! \u0001"]'
+    assert_equal json, utf8.to_json(:ascii_only => false)
+    assert_equal utf8, parse(json)
+    json = '["\u00a9 \u2260 \u20ac! \u0001"]'
+    assert_equal json, utf8.to_json(:ascii_only => true)
+    assert_equal utf8, parse(json)
+    utf8 = ["\343\201\202\343\201\204\343\201\206\343\201\210\343\201\212"]
+    json = "[\"\343\201\202\343\201\204\343\201\206\343\201\210\343\201\212\"]"
+    assert_equal utf8, parse(json)
+    assert_equal json, utf8.to_json(:ascii_only => false)
+    utf8 = ["\343\201\202\343\201\204\343\201\206\343\201\210\343\201\212"]
+    assert_equal utf8, parse(json)
+    json = "[\"\\u3042\\u3044\\u3046\\u3048\\u304a\"]"
+    assert_equal json, utf8.to_json(:ascii_only => true)
+    assert_equal utf8, parse(json)
+    utf8 = ['საქართველო']
+    json = '["საქართველო"]'
+    assert_equal json, utf8.to_json(:ascii_only => false)
+    json = "[\"\\u10e1\\u10d0\\u10e5\\u10d0\\u10e0\\u10d7\\u10d5\\u10d4\\u10da\\u10dd\"]"
+    assert_equal json, utf8.to_json(:ascii_only => true)
+    assert_equal utf8, parse(json)
+    assert_equal '["Ã"]', generate(["Ã"], :ascii_only => false)
+    assert_equal '["\\u00c3"]', generate(["Ã"], :ascii_only => true)
+    assert_equal ["€"], parse('["\u20ac"]')
+    utf8 = ["\xf0\xa0\x80\x81"]
+    json = "[\"\xf0\xa0\x80\x81\"]"
+    assert_equal json, generate(utf8, :ascii_only => false)
+    assert_equal utf8, parse(json)
+    json = '["\ud840\udc01"]'
+    assert_equal json, generate(utf8, :ascii_only => true)
+    assert_equal utf8, parse(json)
+  end
+
+  def test_chars
+    (0..0x7f).each do |i|
+      json = '["\u%04x"]' % i
+      if RUBY_VERSION >= "1.9."
+        i = i.chr
+      end
+      assert_equal i, parse(json).first[0]
+      if i == ?\b
+        generated = generate(["" << i])
+        assert '["\b"]' == generated || '["\10"]' == generated
+      elsif [?\n, ?\r, ?\t, ?\f].include?(i)
+        assert_equal '[' << ('' << i).dump << ']', generate(["" << i])
+      elsif i.chr < 0x20.chr
+        assert_equal json, generate(["" << i])
+      end
+    end
+    assert_raise(JSON::GeneratorError) do
+      generate(["\x80"], :ascii_only => true)
     end
+    assert_equal "\302\200", parse('["\u0080"]').first
   end
 end
diff --git a/test/json/test_json_ext_parser.rb b/test/json/test_json_ext_parser.rb
new file mode 100644
index 0000000000..5cd12f0dcb
--- /dev/null
+++ b/test/json/test_json_ext_parser.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: false
+require 'test_helper'
+
+class TestJSONExtParser < Test::Unit::TestCase
+  if defined?(JSON::Ext::Parser)
+    def test_allocate
+      parser = JSON::Ext::Parser.new("{}")
+      assert_raise(TypeError, '[ruby-core:35079]') do
+        parser.__send__(:initialize, "{}")
+      end
+      parser = JSON::Ext::Parser.allocate
+      assert_raise(TypeError, '[ruby-core:35079]') { parser.source }
+    end
+  end
+
+  if EnvUtil.gc_stress_to_class?
+    def assert_no_memory_leak(code, *rest, **opt)
+      code = "8.times {20_000.times {begin #{code}; rescue NoMemoryError; end}; GC.start}"
+      super(["-rjson/ext/parser"],
+            "GC.add_stress_to_class(JSON::Ext::Parser); "\
+            "#{code}", code, *rest, rss: true, limit: 1.1, **opt)
+    end
+
+    def test_no_memory_leak_allocate
+      assert_no_memory_leak("JSON::Ext::Parser.allocate")
+    end
+  end
+end
diff --git a/test/json/test_json_fixtures.rb b/test/json/test_json_fixtures.rb
index e192706d6b..59bcb12637 100644
--- a/test/json/test_json_fixtures.rb
+++ b/test/json/test_json_fixtures.rb
@@ -1,13 +1,9 @@
-#!/usr/bin/env ruby
-# encoding: utf-8
 # frozen_string_literal: false
-
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
+require 'test_helper'
 
 class TestJSONFixtures < Test::Unit::TestCase
   def setup
-    fixtures = File.join(File.dirname(__FILE__), 'fixtures/*.json')
+    fixtures = File.join(File.dirname(__FILE__), 'fixtures/{fail,pass}.json')
     passed, failed = Dir[fixtures].partition { |f| f['pass'] }
     @passed = passed.inject([]) { |a, f| a << [ f, File.read(f) ] }.sort
     @failed = failed.inject([]) { |a, f| a << [ f, File.read(f) ] }.sort
diff --git a/test/json/test_json_generate.rb b/test/json/test_json_generator.rb
index e5ae3f4987..05235b39db 100644
--- a/test/json/test_json_generate.rb
+++ b/test/json/test_json_generator.rb
@@ -2,10 +2,9 @@
 # encoding: utf-8
 # frozen_string_literal: false
 
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
+require 'test_helper'
 
-class TestJSONGenerate < Test::Unit::TestCase
+class TestJSONGenerator < Test::Unit::TestCase
   include JSON
 
   def setup
@@ -43,23 +42,23 @@ EOT
 
   def test_generate
     json = generate(@hash)
-    assert_equal(JSON.parse(@json2), JSON.parse(json))
+    assert_equal(parse(@json2), parse(json))
     json = JSON[@hash]
-    assert_equal(JSON.parse(@json2), JSON.parse(json))
+    assert_equal(parse(@json2), parse(json))
     parsed_json = parse(json)
     assert_equal(@hash, parsed_json)
     json = generate({1=>2})
     assert_equal('{"1":2}', json)
     parsed_json = parse(json)
     assert_equal({"1"=>2}, parsed_json)
-    assert_raise(GeneratorError) { generate(666) }
-    assert_equal '666', generate(666, :quirks_mode => true)
+    assert_equal '666', generate(666)
   end
 
   def test_generate_pretty
     json = pretty_generate(@hash)
-    # hashes aren't (insertion) ordered on every ruby implementation assert_equal(@json3, json)
-    assert_equal(JSON.parse(@json3), JSON.parse(json))
+    # hashes aren't (insertion) ordered on every ruby implementation
+    # assert_equal(@json3, json)
+    assert_equal(parse(@json3), parse(json))
     parsed_json = parse(json)
     assert_equal(@hash, parsed_json)
     json = pretty_generate({1=>2})
@@ -70,8 +69,7 @@ EOT
 EOT
     parsed_json = parse(json)
     assert_equal({"1"=>2}, parsed_json)
-    assert_raise(GeneratorError) { pretty_generate(666) }
-    assert_equal '666', pretty_generate(666, :quirks_mode => true)
+    assert_equal '666', pretty_generate(666)
   end
 
   def test_generate_custom
@@ -89,30 +87,26 @@ EOT
 
   def test_fast_generate
     json = fast_generate(@hash)
-    assert_equal(JSON.parse(@json2), JSON.parse(json))
+    assert_equal(parse(@json2), parse(json))
     parsed_json = parse(json)
     assert_equal(@hash, parsed_json)
     json = fast_generate({1=>2})
     assert_equal('{"1":2}', json)
     parsed_json = parse(json)
     assert_equal({"1"=>2}, parsed_json)
-    assert_raise(GeneratorError) { fast_generate(666) }
-    assert_equal '666', fast_generate(666, :quirks_mode => true)
+    assert_equal '666', fast_generate(666)
   end
 
   def test_own_state
     state = State.new
     json = generate(@hash, state)
-    assert_equal(JSON.parse(@json2), JSON.parse(json))
+    assert_equal(parse(@json2), parse(json))
     parsed_json = parse(json)
     assert_equal(@hash, parsed_json)
     json = generate({1=>2}, state)
     assert_equal('{"1":2}', json)
     parsed_json = parse(json)
     assert_equal({"1"=>2}, parsed_json)
-    assert_raise(GeneratorError) { generate(666, state) }
-    state.quirks_mode = true
-    assert state.quirks_mode?
     assert_equal '666', generate(666, state)
   end
 
@@ -141,7 +135,6 @@ EOT
       :array_nl              => "\n",
       :ascii_only            => false,
       :buffer_initial_length => 1024,
-      :quirks_mode           => false,
       :depth                 => 0,
       :indent                => "  ",
       :max_nesting           => 100,
@@ -158,7 +151,6 @@ EOT
       :array_nl              => "",
       :ascii_only            => false,
       :buffer_initial_length => 1024,
-      :quirks_mode           => false,
       :depth                 => 0,
       :indent                => "",
       :max_nesting           => 100,
@@ -175,7 +167,6 @@ EOT
       :array_nl              => "",
       :ascii_only            => false,
       :buffer_initial_length => 1024,
-      :quirks_mode           => false,
       :depth                 => 0,
       :indent                => "",
       :max_nesting           => 0,
@@ -206,7 +197,7 @@ EOT
   def test_depth
     ary = []; ary << ary
     assert_equal 0, JSON::SAFE_STATE_PROTOTYPE.depth
-    assert_raise(JSON::NestingError) { JSON.generate(ary) }
+    assert_raise(JSON::NestingError) { generate(ary) }
     assert_equal 0, JSON::SAFE_STATE_PROTOTYPE.depth
     assert_equal 0, JSON::PRETTY_STATE_PROTOTYPE.depth
     assert_raise(JSON::NestingError) { JSON.pretty_generate(ary) }
@@ -286,7 +277,7 @@ EOT
   if defined?(JSON::Ext::Generator)
     def test_broken_bignum # [ruby-core:38867]
       pid = fork do
-        Integer.class_eval do
+        Bignum.class_eval do
           def to_s
           end
         end
@@ -332,17 +323,54 @@ EOT
 
   def test_json_generate
     assert_raise JSON::GeneratorError do
-      assert_equal true, JSON.generate(["\xea"])
+      assert_equal true, generate(["\xea"])
     end
   end
 
+  def test_nesting
+    too_deep = '[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]'
+    too_deep_ary = eval too_deep
+    assert_raise(JSON::NestingError) { generate too_deep_ary }
+    assert_raise(JSON::NestingError) { generate too_deep_ary, :max_nesting => 100 }
+    ok = generate too_deep_ary, :max_nesting => 101
+    assert_equal too_deep, ok
+    ok = generate too_deep_ary, :max_nesting => nil
+    assert_equal too_deep, ok
+    ok = generate too_deep_ary, :max_nesting => false
+    assert_equal too_deep, ok
+    ok = generate too_deep_ary, :max_nesting => 0
+    assert_equal too_deep, ok
+  end
+
+  def test_backslash
+    data = [ '\\.(?i:gif|jpe?g|png)$' ]
+    json = '["\\\\.(?i:gif|jpe?g|png)$"]'
+    assert_equal json, generate(data)
+    #
+    data = [ '\\"' ]
+    json = '["\\\\\""]'
+    assert_equal json, generate(data)
+    #
+    data = [ '/' ]
+    json = '["/"]'
+    assert_equal json, generate(data)
+    #
+    data = ['"']
+    json = '["\""]'
+    assert_equal json, generate(data)
+    #
+    data = ["'"]
+    json = '["\\\'"]'
+    assert_equal '["\'"]', generate(data)
+  end
+
   def test_string_subclass
     s = Class.new(String) do
       def to_s; self; end
       undef to_json
     end
     assert_nothing_raised(SystemStackError) do
-      assert_equal '[""]', JSON.generate([s.new])
+      assert_equal '["foo"]', JSON.generate([s.new('foo')])
     end
   end
 
diff --git a/test/json/test_json_generic_object.rb b/test/json/test_json_generic_object.rb
index e04e1a1cb3..a3fd6b860a 100644
--- a/test/json/test_json_generic_object.rb
+++ b/test/json/test_json_generic_object.rb
@@ -1,9 +1,6 @@
-#!/usr/bin/env ruby
-# encoding: utf-8
 # frozen_string_literal: false
+require 'test_helper'
 
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
 class TestJSONGenericObject < Test::Unit::TestCase
   include JSON
 
@@ -27,11 +24,20 @@ class TestJSONGenericObject < Test::Unit::TestCase
   end
 
   def test_parse_json
-    assert_kind_of Hash, JSON('{ "json_class": "JSON::GenericObject", "a": 1, "b": 2 }', :create_additions => true)
+    assert_kind_of Hash,
+      JSON(
+        '{ "json_class": "JSON::GenericObject", "a": 1, "b": 2 }',
+        :create_additions => true
+      )
     switch_json_creatable do
-      assert_equal @go, l = JSON('{ "json_class": "JSON::GenericObject", "a": 1, "b": 2 }', :create_additions => true)
+      assert_equal @go, l =
+        JSON(
+          '{ "json_class": "JSON::GenericObject", "a": 1, "b": 2 }',
+             :create_additions => true
+        )
       assert_equal 1, l.a
-      assert_equal @go, l = JSON('{ "a": 1, "b": 2 }', :object_class => GenericObject)
+      assert_equal @go,
+        l = JSON('{ "a": 1, "b": 2 }', :object_class => GenericObject)
       assert_equal 1, l.a
       assert_equal GenericObject[:a => GenericObject[:b => 2]],
         l = JSON('{ "a": { "b": 2 } }', :object_class => GenericObject)
diff --git a/test/json/test_json_parser.rb b/test/json/test_json_parser.rb
new file mode 100644
index 0000000000..98193bfbf7
--- /dev/null
+++ b/test/json/test_json_parser.rb
@@ -0,0 +1,448 @@
+# encoding: utf-8
+# frozen_string_literal: false
+require 'test_helper'
+require 'stringio'
+require 'tempfile'
+require 'ostruct'
+
+class TestJSONParser < Test::Unit::TestCase
+  include JSON
+
+  def test_construction
+    parser = JSON::Parser.new('test')
+    assert_equal 'test', parser.source
+  end
+
+  def test_argument_encoding
+    source = "{}".encode("UTF-16")
+    JSON::Parser.new(source)
+    assert_equal Encoding::UTF_16, source.encoding
+  end if defined?(Encoding::UTF_16)
+
+  def test_error_message_encoding
+    bug10705 = '[ruby-core:67386] [Bug #10705]'
+    json = ".\"\xE2\x88\x9A\"".force_encoding(Encoding::UTF_8)
+    e = assert_raise(JSON::ParserError) {
+      JSON::Ext::Parser.new(json).parse
+    }
+    assert_equal(Encoding::UTF_8, e.message.encoding, bug10705)
+    assert_include(e.message, json, bug10705)
+  end if defined?(Encoding::UTF_8) and defined?(JSON::Ext::Parser)
+
+  def test_parsing
+    parser = JSON::Parser.new('"test"')
+    assert_equal 'test', parser.parse
+  end
+
+  def test_parser_reset
+    parser = Parser.new('{"a":"b"}')
+    assert_equal({ 'a' => 'b' }, parser.parse)
+    assert_equal({ 'a' => 'b' }, parser.parse)
+  end
+
+  def test_parse_simple_arrays
+    assert_equal([],             parse('[]'))
+    assert_equal([],             parse('  [  ] '))
+    assert_equal([ nil ],        parse('[null]'))
+    assert_equal([ false ],      parse('[false]'))
+    assert_equal([ true ],       parse('[true]'))
+    assert_equal([ -23 ],        parse('[-23]'))
+    assert_equal([ 23 ],         parse('[23]'))
+    assert_equal_float([ 0.23 ], parse('[0.23]'))
+    assert_equal_float([ 0.0 ],  parse('[0e0]'))
+    assert_equal([""],           parse('[""]'))
+    assert_equal(["foobar"],     parse('["foobar"]'))
+    assert_equal([{}],           parse('[{}]'))
+  end
+
+  def test_parse_simple_objects
+    assert_equal({}, parse('{}'))
+    assert_equal({}, parse(' {   }   '))
+    assert_equal({ "a" => nil }, parse('{   "a"   :  null}'))
+    assert_equal({ "a" => nil }, parse('{"a":null}'))
+    assert_equal({ "a" => false }, parse('{   "a"  :  false  }  '))
+    assert_equal({ "a" => false }, parse('{"a":false}'))
+    assert_raise(JSON::ParserError) { parse('{false}') }
+    assert_equal({ "a" => true }, parse('{"a":true}'))
+    assert_equal({ "a" => true }, parse('  { "a" :  true  }   '))
+    assert_equal({ "a" => -23 }, parse('  {  "a"  :  -23  }  '))
+    assert_equal({ "a" => -23 }, parse('  { "a" : -23 } '))
+    assert_equal({ "a" => 23 }, parse('{"a":23  } '))
+    assert_equal({ "a" => 23 }, parse('  { "a"  : 23  } '))
+    assert_equal({ "a" => 0.23 }, parse(' { "a"  :  0.23 }  '))
+    assert_equal({ "a" => 0.23 }, parse('  {  "a"  :  0.23  }  '))
+  end
+
+  def test_parse_numbers
+    assert_raise(JSON::ParserError) { parse('+23.2') }
+    assert_raise(JSON::ParserError) { parse('+23') }
+    assert_raise(JSON::ParserError) { parse('.23') }
+    assert_raise(JSON::ParserError) { parse('023') }
+    assert_equal 23, parse('23')
+    assert_equal -23, parse('-23')
+    assert_equal_float 3.141, parse('3.141')
+    assert_equal_float -3.141, parse('-3.141')
+    assert_equal_float 3.141, parse('3141e-3')
+    assert_equal_float 3.141, parse('3141.1e-3')
+    assert_equal_float 3.141, parse('3141E-3')
+    assert_equal_float 3.141, parse('3141.0E-3')
+    assert_equal_float -3.141, parse('-3141.0e-3')
+    assert_equal_float -3.141, parse('-3141e-3')
+    assert_raise(ParserError) { parse('NaN') }
+    assert parse('NaN', :allow_nan => true).nan?
+    assert_raise(ParserError) { parse('Infinity') }
+    assert_equal 1.0/0, parse('Infinity', :allow_nan => true)
+    assert_raise(ParserError) { parse('-Infinity') }
+    assert_equal -1.0/0, parse('-Infinity', :allow_nan => true)
+  end
+
+  if Array.method_defined?(:permutation)
+    def test_parse_more_complex_arrays
+      a = [ nil, false, true, "foßbar", [ "n€st€d", true ], { "nested" => true, "n€ßt€ð2" => {} }]
+      a.permutation.each do |perm|
+        json = pretty_generate(perm)
+        assert_equal perm, parse(json)
+      end
+    end
+
+    def test_parse_complex_objects
+      a = [ nil, false, true, "foßbar", [ "n€st€d", true ], { "nested" => true, "n€ßt€ð2" => {} }]
+      a.permutation.each do |perm|
+        s = "a"
+        orig_obj = perm.inject({}) { |h, x| h[s.dup] = x; s = s.succ; h }
+        json = pretty_generate(orig_obj)
+        assert_equal orig_obj, parse(json)
+      end
+    end
+  end
+
+  def test_parse_arrays
+    assert_equal([1,2,3], parse('[1,2,3]'))
+    assert_equal([1.2,2,3], parse('[1.2,2,3]'))
+    assert_equal([[],[[],[]]], parse('[[],[[],[]]]'))
+    assert_equal([], parse('[]'))
+    assert_equal([], parse('  [  ]  '))
+    assert_equal([1], parse('[1]'))
+    assert_equal([1], parse('  [ 1  ]  '))
+    ary = [[1], ["foo"], [3.14], [4711.0], [2.718], [nil],
+      [[1, -2, 3]], [false], [true]]
+    assert_equal(ary,
+      parse('[[1],["foo"],[3.14],[47.11e+2],[2718.0E-3],[null],[[1,-2,3]],[false],[true]]'))
+    assert_equal(ary, parse(%Q{   [   [1] , ["foo"]  ,  [3.14] \t ,  [47.11e+2]\s
+      , [2718.0E-3 ],\r[ null] , [[1, -2, 3 ]], [false ],[ true]\n ]  }))
+  end
+
+  def test_parse_json_primitive_values
+    assert_raise(JSON::ParserError) { parse('') }
+    assert_raise(TypeError) { parse(nil) }
+    assert_raise(JSON::ParserError) { parse('  /* foo */ ') }
+    assert_equal nil, parse('null')
+    assert_equal false, parse('false')
+    assert_equal true, parse('true')
+    assert_equal 23, parse('23')
+    assert_equal 1, parse('1')
+    assert_equal_float 3.141, parse('3.141'), 1E-3
+    assert_equal 2 ** 64, parse('18446744073709551616')
+    assert_equal 'foo', parse('"foo"')
+    assert parse('NaN', :allow_nan => true).nan?
+    assert parse('Infinity', :allow_nan => true).infinite?
+    assert parse('-Infinity', :allow_nan => true).infinite?
+    assert_raise(JSON::ParserError) { parse('[ 1, ]') }
+  end
+
+  def test_parse_some_strings
+    assert_equal([""], parse('[""]'))
+    assert_equal(["\\"], parse('["\\\\"]'))
+    assert_equal(['"'], parse('["\""]'))
+    assert_equal(['\\"\\'], parse('["\\\\\\"\\\\"]'))
+    assert_equal(
+      ["\"\b\n\r\t\0\037"],
+      parse('["\"\b\n\r\t\u0000\u001f"]')
+    )
+  end
+
+  def test_parse_big_integers
+    json1 = JSON(orig = (1 << 31) - 1)
+    assert_equal orig, parse(json1)
+    json2 = JSON(orig = 1 << 31)
+    assert_equal orig, parse(json2)
+    json3 = JSON(orig = (1 << 62) - 1)
+    assert_equal orig, parse(json3)
+    json4 = JSON(orig = 1 << 62)
+    assert_equal orig, parse(json4)
+    json5 = JSON(orig = 1 << 64)
+    assert_equal orig, parse(json5)
+  end
+
+  def test_some_wrong_inputs
+    assert_raise(ParserError) { parse('[] bla') }
+    assert_raise(ParserError) { parse('[] 1') }
+    assert_raise(ParserError) { parse('[] []') }
+    assert_raise(ParserError) { parse('[] {}') }
+    assert_raise(ParserError) { parse('{} []') }
+    assert_raise(ParserError) { parse('{} {}') }
+    assert_raise(ParserError) { parse('[NULL]') }
+    assert_raise(ParserError) { parse('[FALSE]') }
+    assert_raise(ParserError) { parse('[TRUE]') }
+    assert_raise(ParserError) { parse('[07]    ') }
+    assert_raise(ParserError) { parse('[0a]') }
+    assert_raise(ParserError) { parse('[1.]') }
+    assert_raise(ParserError) { parse('     ') }
+  end
+
+  def test_symbolize_names
+    assert_equal({ "foo" => "bar", "baz" => "quux" },
+      parse('{"foo":"bar", "baz":"quux"}'))
+    assert_equal({ :foo => "bar", :baz => "quux" },
+      parse('{"foo":"bar", "baz":"quux"}', :symbolize_names => true))
+    assert_raise(ArgumentError) do
+      parse('{}', :symbolize_names => true, :create_additions => true)
+    end
+  end
+
+  def test_parse_comments
+    json = <<EOT
+{
+  "key1":"value1", // eol comment
+  "key2":"value2"  /* multi line
+                    *  comment */,
+  "key3":"value3"  /* multi line
+                    // nested eol comment
+                    *  comment */
+}
+EOT
+    assert_equal(
+      { "key1" => "value1", "key2" => "value2", "key3" => "value3" },
+      parse(json))
+    json = <<EOT
+{
+  "key1":"value1"  /* multi line
+                    // nested eol comment
+                    /* illegal nested multi line comment */
+                    *  comment */
+}
+EOT
+    assert_raise(ParserError) { parse(json) }
+    json = <<EOT
+{
+  "key1":"value1"  /* multi line
+                   // nested eol comment
+                   closed multi comment */
+                   and again, throw an Error */
+}
+EOT
+    assert_raise(ParserError) { parse(json) }
+    json = <<EOT
+{
+  "key1":"value1"  /*/*/
+}
+EOT
+    assert_equal({ "key1" => "value1" }, parse(json))
+  end
+
+  def test_nesting
+    too_deep = '[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]'
+    too_deep_ary = eval too_deep
+    assert_raise(JSON::NestingError) { parse too_deep }
+    assert_raise(JSON::NestingError) { parse too_deep, :max_nesting => 100 }
+    ok = parse too_deep, :max_nesting => 101
+    assert_equal too_deep_ary, ok
+    ok = parse too_deep, :max_nesting => nil
+    assert_equal too_deep_ary, ok
+    ok = parse too_deep, :max_nesting => false
+    assert_equal too_deep_ary, ok
+    ok = parse too_deep, :max_nesting => 0
+    assert_equal too_deep_ary, ok
+  end
+
+  def test_backslash
+    data = [ '\\.(?i:gif|jpe?g|png)$' ]
+    json = '["\\\\.(?i:gif|jpe?g|png)$"]'
+    assert_equal data, parse(json)
+    #
+    data = [ '\\"' ]
+    json = '["\\\\\""]'
+    assert_equal data, parse(json)
+    #
+    json = '["/"]'
+    data = [ '/' ]
+    assert_equal data, parse(json)
+    #
+    json = '["\""]'
+    data = ['"']
+    assert_equal data, parse(json)
+    #
+    json = '["\\\'"]'
+    data = ["'"]
+    assert_equal data, parse(json)
+  end
+
+
+  class SubArray < Array
+    def <<(v)
+      @shifted = true
+      super
+    end
+
+    def shifted?
+      @shifted
+    end
+  end
+
+  class SubArray2 < Array
+    def to_json(*a)
+      {
+        JSON.create_id => self.class.name,
+        'ary'          => to_a,
+      }.to_json(*a)
+    end
+
+    def self.json_create(o)
+      o.delete JSON.create_id
+      o['ary']
+    end
+  end
+
+  class SubArrayWrapper
+    def initialize
+      @data = []
+    end
+
+    attr_reader :data
+
+    def [](index)
+      @data[index]
+    end
+
+    def <<(value)
+      @data << value
+      @shifted = true
+    end
+
+    def shifted?
+      @shifted
+    end
+  end
+
+  def test_parse_array_custom_array_derived_class
+    res = parse('[1,2]', :array_class => SubArray)
+    assert_equal([1,2], res)
+    assert_equal(SubArray, res.class)
+    assert res.shifted?
+  end
+
+  def test_parse_array_custom_non_array_derived_class
+    res = parse('[1,2]', :array_class => SubArrayWrapper)
+    assert_equal([1,2], res.data)
+    assert_equal(SubArrayWrapper, res.class)
+    assert res.shifted?
+  end
+
+  def test_parse_object
+    assert_equal({}, parse('{}'))
+    assert_equal({}, parse('  {  }  '))
+    assert_equal({'foo'=>'bar'}, parse('{"foo":"bar"}'))
+    assert_equal({'foo'=>'bar'}, parse('    { "foo"  :   "bar"   }   '))
+  end
+
+  class SubHash < Hash
+    def []=(k, v)
+      @item_set = true
+      super
+    end
+
+    def item_set?
+      @item_set
+    end
+  end
+
+  class SubHash2 < Hash
+    def to_json(*a)
+      {
+        JSON.create_id => self.class.name,
+      }.merge(self).to_json(*a)
+    end
+
+    def self.json_create(o)
+      o.delete JSON.create_id
+      self[o]
+    end
+  end
+
+  class SubOpenStruct < OpenStruct
+    def [](k)
+      __send__(k)
+    end
+
+    def []=(k, v)
+      @item_set = true
+      __send__("#{k}=", v)
+    end
+
+    def item_set?
+      @item_set
+    end
+  end
+
+  def test_parse_object_custom_hash_derived_class
+    res = parse('{"foo":"bar"}', :object_class => SubHash)
+    assert_equal({"foo" => "bar"}, res)
+    assert_equal(SubHash, res.class)
+    assert res.item_set?
+  end
+
+  def test_parse_object_custom_non_hash_derived_class
+    res = parse('{"foo":"bar"}', :object_class => SubOpenStruct)
+    assert_equal "bar", res.foo
+    assert_equal(SubOpenStruct, res.class)
+    assert res.item_set?
+  end
+
+  def test_parse_generic_object
+    res = parse(
+      '{"foo":"bar", "baz":{}}',
+      :object_class => JSON::GenericObject
+    )
+    assert_equal(JSON::GenericObject, res.class)
+    assert_equal "bar", res.foo
+    assert_equal "bar", res["foo"]
+    assert_equal "bar", res[:foo]
+    assert_equal "bar", res.to_hash[:foo]
+    assert_equal(JSON::GenericObject, res.baz.class)
+  end
+
+  def test_generate_core_subclasses_with_new_to_json
+    obj = SubHash2["foo" => SubHash2["bar" => true]]
+    obj_json = JSON(obj)
+    obj_again = parse(obj_json, :create_additions => true)
+    assert_kind_of SubHash2, obj_again
+    assert_kind_of SubHash2, obj_again['foo']
+    assert obj_again['foo']['bar']
+    assert_equal obj, obj_again
+    assert_equal ["foo"],
+      JSON(JSON(SubArray2["foo"]), :create_additions => true)
+  end
+
+  def test_generate_core_subclasses_with_default_to_json
+    assert_equal '{"foo":"bar"}', JSON(SubHash["foo" => "bar"])
+    assert_equal '["foo"]', JSON(SubArray["foo"])
+  end
+
+  def test_generate_of_core_subclasses
+    obj = SubHash["foo" => SubHash["bar" => true]]
+    obj_json = JSON(obj)
+    obj_again = JSON(obj_json)
+    assert_kind_of Hash, obj_again
+    assert_kind_of Hash, obj_again['foo']
+    assert obj_again['foo']['bar']
+    assert_equal obj, obj_again
+  end
+
+  private
+
+  def assert_equal_float(expected, actual, delta = 1e-2)
+    Array === expected and expected = expected.first
+    Array === actual and actual = actual.first
+    assert_in_delta(expected, actual, delta)
+  end
+end
diff --git a/test/json/test_json_string_matching.rb b/test/json/test_json_string_matching.rb
index 6158231103..530e3644fa 100644
--- a/test/json/test_json_string_matching.rb
+++ b/test/json/test_json_string_matching.rb
@@ -1,10 +1,5 @@
-#!/usr/bin/env ruby
-# encoding: utf-8
 # frozen_string_literal: false
-
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
-require 'stringio'
+require 'test_helper'
 require 'time'
 
 class TestJSONStringMatching < Test::Unit::TestCase
@@ -27,14 +22,17 @@ class TestJSONStringMatching < Test::Unit::TestCase
   def test_match_date
     t = TestTime.new
     t_json = [ t ].to_json
+    time_regexp = /\A\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[+-]\d{4}\z/
     assert_equal [ t ],
-      JSON.parse(t_json, :create_additions => true,
-        :match_string => { /\A\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[+-]\d{4}\z/ => TestTime })
-    assert_equal [ t.strftime('%FT%T%z') ],
-      JSON.parse(t_json, :create_additions => true,
-        :match_string => { /\A\d{3}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[+-]\d{4}\z/ => TestTime })
+      parse(
+        t_json,
+        :create_additions => true,
+        :match_string => { time_regexp => TestTime }
+      )
     assert_equal [ t.strftime('%FT%T%z') ],
-      JSON.parse(t_json,
-        :match_string => { /\A\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[+-]\d{4}\z/ => TestTime })
+      parse(
+        t_json,
+        :match_string => { time_regexp => TestTime }
+      )
   end
 end
diff --git a/test/json/test_json_unicode.rb b/test/json/test_json_unicode.rb
deleted file mode 100644
index 16234f0491..0000000000
--- a/test/json/test_json_unicode.rb
+++ /dev/null
@@ -1,73 +0,0 @@
-#!/usr/bin/env ruby
-# encoding: utf-8
-# frozen_string_literal: false
-
-require 'test/unit'
-require File.join(File.dirname(__FILE__), 'setup_variant')
-
-class TestJSONUnicode < Test::Unit::TestCase
-  include JSON
-
-  def test_unicode
-    assert_equal '""', ''.to_json
-    assert_equal '"\\b"', "\b".to_json
-    assert_equal '"\u0001"', 0x1.chr.to_json
-    assert_equal '"\u001f"', 0x1f.chr.to_json
-    assert_equal '" "', ' '.to_json
-    assert_equal "\"#{0x7f.chr}\"", 0x7f.chr.to_json
-    utf8 = [ "© ≠ €! \01" ]
-    json = '["© ≠ €! \u0001"]'
-    assert_equal json, utf8.to_json(:ascii_only => false)
-    assert_equal utf8, parse(json)
-    json = '["\u00a9 \u2260 \u20ac! \u0001"]'
-    assert_equal json, utf8.to_json(:ascii_only => true)
-    assert_equal utf8, parse(json)
-    utf8 = ["\343\201\202\343\201\204\343\201\206\343\201\210\343\201\212"]
-    json = "[\"\343\201\202\343\201\204\343\201\206\343\201\210\343\201\212\"]"
-    assert_equal utf8, parse(json)
-    assert_equal json, utf8.to_json(:ascii_only => false)
-    utf8 = ["\343\201\202\343\201\204\343\201\206\343\201\210\343\201\212"]
-    assert_equal utf8, parse(json)
-    json = "[\"\\u3042\\u3044\\u3046\\u3048\\u304a\"]"
-    assert_equal json, utf8.to_json(:ascii_only => true)
-    assert_equal utf8, parse(json)
-    utf8 = ['საქართველო']
-    json = '["საქართველო"]'
-    assert_equal json, utf8.to_json(:ascii_only => false)
-    json = "[\"\\u10e1\\u10d0\\u10e5\\u10d0\\u10e0\\u10d7\\u10d5\\u10d4\\u10da\\u10dd\"]"
-    assert_equal json, utf8.to_json(:ascii_only => true)
-    assert_equal utf8, parse(json)
-    assert_equal '["Ã"]', JSON.generate(["Ã"], :ascii_only => false)
-    assert_equal '["\\u00c3"]', JSON.generate(["Ã"], :ascii_only => true)
-    assert_equal ["€"], JSON.parse('["\u20ac"]')
-    utf8 = ["\xf0\xa0\x80\x81"]
-    json = "[\"\xf0\xa0\x80\x81\"]"
-    assert_equal json, JSON.generate(utf8, :ascii_only => false)
-    assert_equal utf8, JSON.parse(json)
-    json = '["\ud840\udc01"]'
-    assert_equal json, JSON.generate(utf8, :ascii_only => true)
-    assert_equal utf8, JSON.parse(json)
-  end
-
-  def test_chars
-    (0..0x7f).each do |i|
-      json = '["\u%04x"]' % i
-      if RUBY_VERSION >= "1.9."
-        i = i.chr
-      end
-      assert_equal i, JSON.parse(json).first[0]
-      if i == ?\b
-        generated = JSON.generate(["" << i])
-        assert '["\b"]' == generated || '["\10"]' == generated
-      elsif [?\n, ?\r, ?\t, ?\f].include?(i)
-        assert_equal '[' << ('' << i).dump << ']', JSON.generate(["" << i])
-      elsif i.chr < 0x20.chr
-        assert_equal json, JSON.generate(["" << i])
-      end
-    end
-    assert_raise(JSON::GeneratorError) do
-      JSON.generate(["\x80"], :ascii_only => true)
-    end
-    assert_equal "\302\200", JSON.parse('["\u0080"]').first
-  end
-end