Workaround rubygems $LOAD_PATH bug

CHANGES.md

@@ -1,5 +1,9 @@
 # Changes
 
+* Workaround a bug in 3.4.8 and older https://github.com/rubygems/rubygems/pull/6490.
+* Workaround different versions of `json` and `json_pure` being loaded (not officially supported).
+* Make `json_pure` Ractor compatible. 
+
 ### 2024-10-24 (2.7.3)
 
 * Numerous performance optimizations in `JSON.generate` and `JSON.dump` (up to 2 times faster).

ext/json/ext/generator/generator.c

@@ -963,6 +963,12 @@ static VALUE cState_generate(VALUE self, VALUE obj)
     return result;
 }
 
+static VALUE cState_initialize(int argc, VALUE *argv, VALUE self)
+{
+    rb_warn("The json gem extension was loaded with the stdlib ruby code. You should upgrade rubygems with `gem update --system`");
+    return self;
+}
+
 /*
  * call-seq: initialize_copy(orig)
  *
@@ -1408,6 +1414,9 @@ void Init_generator(void)
     cState = rb_define_class_under(mGenerator, "State", rb_cObject);
     rb_define_alloc_func(cState, cState_s_allocate);
     rb_define_singleton_method(cState, "from_state", cState_from_state_s, 1);
+    rb_define_method(cState, "initialize", cState_initialize, -1);
+    rb_define_alias(cState, "initialize", "initialize"); // avoid method redefinition warnings
+
     rb_define_method(cState, "initialize_copy", cState_init_copy, 1);
     rb_define_method(cState, "indent", cState_indent, 0);
     rb_define_method(cState, "indent=", cState_indent_set, 1);
@@ -1498,4 +1507,6 @@ void Init_generator(void)
     usascii_encindex = rb_usascii_encindex();
     utf8_encindex = rb_utf8_encindex();
     binary_encindex = rb_ascii8bit_encindex();
+
+    rb_require("json/ext/generator/state");
 }

lib/json/ext.rb

@@ -15,9 +15,6 @@ module Ext
     else
       require 'json/ext/parser'
       require 'json/ext/generator'
-      unless RUBY_ENGINE == 'jruby'
-        require 'json/ext/generator/state'
-      end
       $DEBUG and warn "Using Ext extension for JSON."
       JSON.parser = Parser
       JSON.generator = Generator

lib/json/pure/parser.rb

@@ -148,25 +148,26 @@ def convert_encoding(source)
       end
 
       # Unescape characters in strings.
-      UNESCAPE_MAP = Hash.new { |h, k| h[k] = k.chr }
-      UNESCAPE_MAP.update({
-        ?"  => '"',
-        ?\\ => '\\',
-        ?/  => '/',
-        ?b  => "\b",
-        ?f  => "\f",
-        ?n  => "\n",
-        ?r  => "\r",
-        ?t  => "\t",
-        ?u  => nil,
-      })
+      # UNESCAPE_MAP = Hash.new { |h, k| puts; p [:k, k]; h[k] = k.chr }
+      UNESCAPE_MAP = {
+        '"'  => '"',
+        '\\' => '\\',
+        '/'  => '/',
+        'b'  => "\b",
+        'f'  => "\f",
+        'n'  => "\n",
+        'r'  => "\r",
+        't'  => "\t",
+        'u'  => nil,
+      }.freeze
 
       STR_UMINUS = ''.respond_to?(:-@)
       def parse_string
         if scan(STRING)
           return '' if self[1].empty?
-          string = self[1].gsub(%r((?:\\[\\bfnrt"/]|(?:\\u(?:[A-Fa-f\d]{4}))+|\\[\x20-\xff]))n) do |c|
-            if u = UNESCAPE_MAP[$&[1]]
+          string = self[1].gsub(%r{(?:\\[\\bfnrt"/]|(?:\\u(?:[A-Fa-f\d]{4}))+|\\[\x20-\xff])}n) do |c|
+            k = $&[1]
+            if u = UNESCAPE_MAP.fetch(k) { k.chr }
               u
             else # \uXXXX
               bytes = ''.b

test/json/json_generator_test.rb

@@ -261,19 +261,19 @@ def test_buffer_initial_length
   end
 
   def test_gc
-    if respond_to?(:assert_in_out_err) && !(RUBY_PLATFORM =~ /java/)
-      assert_in_out_err(%w[-rjson -Ilib -Iext], <<-EOS, [], [])
-        bignum_too_long_to_embed_as_string = 1234567890123456789012345
-        expect = bignum_too_long_to_embed_as_string.to_s
-        GC.stress = true
-
-        10.times do |i|
-          tmp = bignum_too_long_to_embed_as_string.to_json
-          raise "'\#{expect}' is expected, but '\#{tmp}'" unless tmp == expect
-        end
-      EOS
+    pid = fork do
+      bignum_too_long_to_embed_as_string = 1234567890123456789012345
+      expect = bignum_too_long_to_embed_as_string.to_s
+      GC.stress = true
+
+      10.times do |i|
+        tmp = bignum_too_long_to_embed_as_string.to_json
+        raise "#{expect}' is expected, but '#{tmp}'" unless tmp == expect
+      end
     end
-  end if GC.respond_to?(:stress=)
+    _, status = Process.waitpid2(pid)
+    assert_predicate status, :success?
+  end if GC.respond_to?(:stress=) && Process.respond_to?(:fork)
 
   def test_configure_using_configure_and_merge
     numbered_state = {

test/json/ractor_test.rb

@@ -9,10 +9,7 @@
 
 class JSONInRactorTest < Test::Unit::TestCase
   def test_generate
-    assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}", ignore_stderr: true)
-    begin;
-      $VERBOSE = nil
-      require "json"
+    pid = fork do
       r = Ractor.new do
         json = JSON.generate({
           'a' => 2,
@@ -26,9 +23,22 @@ def test_generate
         })
         JSON.parse(json)
       end
-      expected_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}'
-      assert_equal(JSON.parse(expected_json), r.take)
-    end;
+      expected_json = JSON.parse('{"a":2,"b":3.141,"c":"c","d":[1,"b",3.14],"e":{"foo":"bar"},' +
+                      '"g":"\\"\\u0000\\u001f","h":1000.0,"i":0.001}')
+      actual_json = r.take
+
+      if expected_json == actual_json
+        exit 0
+      else
+        puts "Expected:"
+        puts expected_json
+        puts "Acutual:"
+        puts actual_json
+        puts
+        exit 1
+      end
+    end
+    _, status = Process.waitpid2(pid)
+    assert_predicate status, :success?
   end
-end if defined?(Ractor)
+end if defined?(Ractor) && Process.respond_to?(:fork)

test/json/test_helper.rb

@@ -1,12 +1,12 @@
 case ENV['JSON']
 when 'pure'
-  $:.unshift File.join(__dir__, '../../lib')
+  $LOAD_PATH.unshift(File.expand_path('../../../lib', __FILE__))
   require 'json/pure'
 when 'ext'
-  $:.unshift File.join(__dir__, '../../ext'), File.join(__dir__, '../../lib')
+  $LOAD_PATH.unshift(File.expand_path('../../../ext', __FILE__), File.expand_path('../../../lib', __FILE__))
   require 'json/ext'
 else
-  $:.unshift File.join(__dir__, '../../ext'), File.join(__dir__, '../../lib')
+  $LOAD_PATH.unshift(File.expand_path('../../../ext', __FILE__), File.expand_path('../../../lib', __FILE__))
   require 'json'
 end