From 101ac364a54b10a24e2351c2138b59a819665540 Mon Sep 17 00:00:00 2001
From: Tim Morgan <tim@timmorgan.org>
Date: Fri, 15 Sep 2023 11:26:13 -0500
Subject: [PATCH] [ruby/yarp] Return Regexp options that match MRI for e, u, s,
 and n

https://github.com/ruby/yarp/commit/17dbf4ec46
---
 lib/yarp.rb              | 22 ++++++++++++++--------
 test/yarp/regexp_test.rb | 14 ++++++++++++++
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/lib/yarp.rb b/lib/yarp.rb
index c1043c3232..a2940a2eaa 100644
--- a/lib/yarp.rb
+++ b/lib/yarp.rb
@@ -587,11 +587,14 @@ module YARP
 
   class InterpolatedRegularExpressionNode < Node
     # Returns a numeric value that represents the flags that were used to create
-    # the regular expression. This mirrors the Regexp#options method in Ruby.
-    # Note that this is effectively masking only the three common flags that are
-    # used in Ruby, and does not include the full set of flags like encoding.
+    # the regular expression.
     def options
-      flags & 0b111
+      o = flags & 0b111
+      o |= Regexp::FIXEDENCODING if flags & 8 != 0  # 'e'
+      o |= Regexp::FIXEDENCODING if flags & 32 != 0 # 's'
+      o |= Regexp::FIXEDENCODING if flags & 64 != 0 # 'u'
+      o |= Regexp::NOENCODING if flags & 16 != 0    # 'n'
+      o
     end
   end
 
@@ -604,11 +607,14 @@ module YARP
 
   class RegularExpressionNode < Node
     # Returns a numeric value that represents the flags that were used to create
-    # the regular expression. This mirrors the Regexp#options method in Ruby.
-    # Note that this is effectively masking only the three common flags that are
-    # used in Ruby, and does not include the full set of flags like encoding.
+    # the regular expression.
     def options
-      flags & 0b111
+      o = flags & 0b111
+      o |= Regexp::FIXEDENCODING if flags & 8 != 0  # 'e'
+      o |= Regexp::FIXEDENCODING if flags & 32 != 0 # 's'
+      o |= Regexp::FIXEDENCODING if flags & 64 != 0 # 'u'
+      o |= Regexp::NOENCODING if flags & 16 != 0    # 'n'
+      o
     end
   end
 end
diff --git a/test/yarp/regexp_test.rb b/test/yarp/regexp_test.rb
index c2f92e2bd1..865c70a2c8 100644
--- a/test/yarp/regexp_test.rb
+++ b/test/yarp/regexp_test.rb
@@ -208,6 +208,20 @@ module YARP
       assert_equal(Regexp::MULTILINE, options("m"))
     end
 
+    def test_flag_fixedencoding
+      assert_equal(Regexp::FIXEDENCODING, options("e"))
+      assert_equal(Regexp::FIXEDENCODING, options("u"))
+      assert_equal(Regexp::FIXEDENCODING, options("s"))
+    end
+
+    def test_flag_noencoding
+      assert_equal(Regexp::NOENCODING, options("n"))
+    end
+
+    def test_flag_once
+      assert_equal(0, options("o"))
+    end
+
     def test_flag_combined
       value = Regexp::IGNORECASE | Regexp::MULTILINE | Regexp::EXTENDED
       assert_equal(value, options("mix"))