1 files changed, 275 insertions, 0 deletions
diff --git a/test/json/json_encoding_test.rb b/test/json/json_encoding_test.rb
new file mode 100644
index 0000000000..7ac06b2a7b
--- /dev/null
+++ b/test/json/json_encoding_test.rb
@@ -0,0 +1,275 @@
+# frozen_string_literal: true
+
+require_relative 'test_helper'
+
+class JSONEncodingTest < Test::Unit::TestCase
+  include JSON
+
+  def setup
+    @utf_8      = '"© ≠ €!"'
+    @ascii_8bit = @utf_8.b
+    @parsed     = "© ≠ €!"
+    @generated  = '"\u00a9 \u2260 \u20ac!"'
+    @utf_16_data = @parsed.encode(Encoding::UTF_16BE, Encoding::UTF_8)
+    @utf_16be = @utf_8.encode(Encoding::UTF_16BE, Encoding::UTF_8)
+    @utf_16le = @utf_8.encode(Encoding::UTF_16LE, Encoding::UTF_8)
+    @utf_32be = @utf_8.encode(Encoding::UTF_32BE, Encoding::UTF_8)
+    @utf_32le = @utf_8.encode(Encoding::UTF_32LE, Encoding::UTF_8)
+  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)
+    assert_equal @parsed, JSON.parse(@utf_32be)
+    assert_equal @parsed, JSON.parse(@utf_32le)
+  end
+
+  def test_generate
+    assert_equal @generated, JSON.generate(@parsed, ascii_only: true)
+    assert_equal @generated, JSON.generate(@utf_16_data, ascii_only: true)
+  end
+
+  def test_generate_shared_string
+    # Ref: https://github.com/ruby/json/issues/859
+    s = "01234567890"
+    assert_equal '"234567890"', JSON.dump(s[2..-1])
+    s = '01234567890123456789"a"b"c"d"e"f"g"h'
+    assert_equal '"\"a\"b\"c\"d\"e\"f\"g\""', JSON.dump(s[20, 15])
+    s = "0123456789001234567890012345678900123456789001234567890"
+    assert_equal '"23456789001234567890012345678900123456789001234567890"', JSON.dump(s[2..-1])
+    s = "0123456789001234567890012345678900123456789001234567890"
+    assert_equal '"567890012345678900123456789001234567890012345678"', JSON.dump(s[5..-3])
+  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)
+    assert_raise(JSON::ParserError) { parse('"\u"') }
+    assert_raise(JSON::ParserError) { parse('"\ud800"') }
+  end
+
+  def test_chars
+    (0..0x7f).each do |i|
+      json = '"\u%04x"' % i
+      i = i.chr
+      assert_equal i, parse(json)[0]
+      if i == "\b"
+        generated = generate(i)
+        assert ['"\b"', '"\10"'].include?(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"')
+  end
+
+  def test_deeply_nested_structures
+    # Test for deeply nested arrays
+    nesting_level = 100
+    deeply_nested = []
+    current = deeply_nested
+
+    (nesting_level - 1).times do
+      current << []
+      current = current[0]
+    end
+
+    json = generate(deeply_nested)
+    assert_equal deeply_nested, parse(json)
+
+    # Test for deeply nested objects/hashes
+    deeply_nested_hash = {}
+    current_hash = deeply_nested_hash
+
+    (nesting_level - 1).times do |i|
+      current_hash["key#{i}"] = {}
+      current_hash = current_hash["key#{i}"]
+    end
+
+    json = generate(deeply_nested_hash)
+    assert_equal deeply_nested_hash, parse(json)
+  end
+
+  def test_very_large_json_strings
+    # Create a large array with repeated elements
+    large_array = Array.new(10_000) { |i| "item#{i}" }
+
+    json = generate(large_array)
+    parsed = parse(json)
+
+    assert_equal large_array.size, parsed.size
+    assert_equal large_array.first, parsed.first
+    assert_equal large_array.last, parsed.last
+
+    # Create a large hash
+    large_hash = {}
+    10_000.times { |i| large_hash["key#{i}"] = "value#{i}" }
+
+    json = generate(large_hash)
+    parsed = parse(json)
+
+    assert_equal large_hash.size, parsed.size
+    assert_equal large_hash["key0"], parsed["key0"]
+    assert_equal large_hash["key9999"], parsed["key9999"]
+  end
+
+  def test_invalid_utf8_sequences
+    invalid_utf8 = "\xFF\xFF"
+    error = assert_raise(JSON::GeneratorError) do
+      generate(invalid_utf8)
+    end
+    assert_match(%r{source sequence is illegal/malformed utf-8}, error.message)
+  end
+
+  def test_surrogate_pair_handling
+    # Test valid surrogate pairs
+    assert_equal "\u{10000}", parse('"\ud800\udc00"')
+    assert_equal "\u{10FFFF}", parse('"\udbff\udfff"')
+
+    # The existing test already checks for orphaned high surrogate
+    assert_raise(JSON::ParserError) { parse('"\ud800"') }
+
+    # Test generating surrogate pairs
+    utf8_string = "\u{10437}"
+    generated = generate(utf8_string, ascii_only: true)
+    assert_match(/\\ud801\\udc37/, generated)
+  end
+
+  def test_json_escaping_edge_cases
+    # Test escaping forward slashes
+    assert_equal "/", parse('"\/"')
+
+    # Test escaping backslashes
+    assert_equal "\\", parse('"\\\\"')
+
+    # Test escaping quotes
+    assert_equal '"', parse('"\\""')
+
+    # Multiple escapes in sequence - different JSON parsers might handle escaped forward slashes differently
+    # Some parsers preserve the escaping, others don't
+    escaped_result = parse('"\\\\\\"\\/"')
+    assert_match(/\\"/, escaped_result)
+    assert_match(%r{/}, escaped_result)
+
+    # Generate string with all special characters
+    special_chars = "\b\f\n\r\t\"\\"
+    escaped_json = generate(special_chars)
+    assert_equal special_chars, parse(escaped_json)
+  end
+
+  def test_empty_objects_and_arrays
+    # Test empty objects with different encodings
+    assert_equal({}, parse('{}'))
+    assert_equal({}, parse('{}'.encode(Encoding::UTF_16BE)))
+    assert_equal({}, parse('{}'.encode(Encoding::UTF_16LE)))
+    assert_equal({}, parse('{}'.encode(Encoding::UTF_32BE)))
+    assert_equal({}, parse('{}'.encode(Encoding::UTF_32LE)))
+
+    # Test empty arrays with different encodings
+    assert_equal([], parse('[]'))
+    assert_equal([], parse('[]'.encode(Encoding::UTF_16BE)))
+    assert_equal([], parse('[]'.encode(Encoding::UTF_16LE)))
+    assert_equal([], parse('[]'.encode(Encoding::UTF_32BE)))
+    assert_equal([], parse('[]'.encode(Encoding::UTF_32LE)))
+
+    # Test generating empty objects and arrays
+    assert_equal '{}', generate({})
+    assert_equal '[]', generate([])
+  end
+
+  def test_null_character_handling
+    # Test parsing null character
+    assert_equal "\u0000", parse('"\u0000"')
+
+    # Test generating null character
+    string_with_null = "\u0000"
+    generated = generate(string_with_null)
+    assert_equal '"\u0000"', generated
+
+    # Test null characters in middle of string
+    mixed_string = "before\u0000after"
+    generated = generate(mixed_string)
+    assert_equal mixed_string, parse(generated)
+  end
+
+  def test_whitespace_handling
+    # Test parsing with various whitespace patterns
+    assert_equal({}, parse(' { } '))
+    assert_equal({}, parse("{\r\n}"))
+    assert_equal([], parse(" [ \n ] "))
+    assert_equal(["a", "b"], parse(" [ \n\"a\",\r\n  \"b\"\n ] "))
+    assert_equal({ "a" => "b" }, parse(" { \n\"a\" \r\n: \t\"b\"\n } "))
+
+    # Test with excessive whitespace
+    excessive_whitespace = " \n\r\t" * 10 + "{}" + " \n\r\t" * 10
+    assert_equal({}, parse(excessive_whitespace))
+
+    # Mixed whitespace in keys and values
+    mixed_json = '{"a \n b":"c \r\n d"}'
+    assert_equal({ "a \n b" => "c \r\n d" }, parse(mixed_json))
+  end
+
+  def test_control_character_handling
+    # Test all control characters (U+0000 to U+001F)
+    (0..0x1F).each do |i|
+      # Skip already tested ones
+      next if [0x08, 0x0A, 0x0D, 0x0C, 0x09].include?(i)
+
+      control_char = i.chr('UTF-8')
+      escaped_json = '"' + "\\u%04x" % i + '"'
+      assert_equal control_char, parse(escaped_json)
+
+      # Check that the character is properly escaped when generating
+      assert_match(/\\u00[0-1][0-9a-f]/, generate(control_char))
+    end
+
+    # Test string with multiple control characters
+    control_str = "\u0001\u0002\u0003\u0004"
+    generated = generate(control_str)
+    assert_equal control_str, parse(generated)
+    assert_match(/\\u0001\\u0002\\u0003\\u0004/, generated)
+  end
+end