Dump/Load regexp with escaped slash

[ayanko]

Problem

$ irb -r psych

irb(main):001:0> Psych.load(Psych.dump(/\d/)) == /\d/
=> true

irb(main):002:0> Psych.load(Psych.dump(/\//)) == /\//
=> false

STR

$ cat  psych_regexp.rb

# frozen_string_literal: true

require 'psych'
require 'test/unit'

class TestPyschRegexpDumpLoad < Test::Unit::TestCase
   def test_psych_version
     assert '3.1.0', Psych::VERSION
   end

   def test_dump_load_regexp_no_escape
     assert_equal "--- !ruby/regexp /^[0-9]+/\n", Psych.dump(/^[0-9]+/)
     assert_equal /^[0-9]+/, Psych.load(Psych.dump(/^[0-9]+/))
   end

   def test_dump_load_regexp_with_slash
     assert_equal "--- !ruby/regexp /^\\//\n", Psych.dump(/^\//)
     assert_equal /^\//, Psych.load(Psych.dump(/^\//))
   end
end

Run

$ ruby psych_regexp.rb

Actual Result

Loaded suite psych_regexp
Started
.F
=====================================================================================================================================================================================
     15:
     16:    def test_dump_load_regexp_with_slash
     17:      assert_equal "--- !ruby/regexp /^\\//\n", Psych.dump(/^\//)
  => 18:      assert_equal /^\//, Psych.load(Psych.dump(/^\//))
     19:    end
     20: end
psych_regexp.rb:18:in `test_dump_load_regexp_with_slash'
</^\//> expected but was
</^\//>

diff:
  /^\//
Failure: test_dump_load_regexp_with_slash(TestPyschRegexpDumpLoad)
=====================================================================================================================================================================================
.
Finished in 0.006877 seconds.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
3 tests, 5 assertions, 1 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
66.6667% passed
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
436.24 tests/s, 727.06 assertions/s

Expected Result

Test passed

[ayanko]

They have different source ...

irb(main):020:0> /\//.source
=> "/"
irb(main):021:0> Psych.load(Psych.dump(/\//)).source
=> "\\/"