[ruby/prism] Ensure last encoding flag wins

You can't encoding a string with more than one encoding so ensure that
the last one wins.

https://github.com/ruby/prism/commit/4182c988c9

1 files changed, 12 insertions, 0 deletions

diff --git a/test/prism/regexp_test.rb b/test/prism/regexp_test.rb
index 67114c7bf3..0a5fc2b4fc 100644
--- a/test/prism/regexp_test.rb
+++ b/test/prism/regexp_test.rb
@@ -227,6 +227,18 @@ module Prism
       assert_equal(value, options("mix"))
     end
 
+    def test_last_encoding_option_wins
+      regex = "/foo/nu"
+      option = Prism.parse(regex).value.statements.body.first.options
+
+      assert_equal Regexp::FIXEDENCODING, option
+
+      regex = "/foo/un"
+      option = Prism.parse(regex).value.statements.body.first.options
+
+      assert_equal Regexp::NOENCODING, option
+    end
+
     private
 
     def named_captures(source)