[ruby/prism] Track newlines in character escape sequences

https://github.com/ruby/prism/commit/2e58c52196

1 files changed, 25 insertions, 2 deletions

diff --git a/test/prism/newline_offsets_test.rb b/test/prism/newline_offsets_test.rb
index 99b808b1df..bb06876a96 100644
--- a/test/prism/newline_offsets_test.rb
+++ b/test/prism/newline_offsets_test.rb
@@ -8,15 +8,38 @@ module Prism
       define_method(fixture.test_name) { assert_newline_offsets(fixture) }
     end
 
+    def test_escape_control_newline
+      # Newlines consumed inside escape sequences like \C-, \c, and \M-
+      # must be tracked in line offsets across all literal types.
+      %w[\\C- \\c \\M-].each do |escape|
+        assert_newline_offsets_for("\"#{escape}\n\"", "#{escape} in string")
+        assert_newline_offsets_for("`#{escape}\n`", "#{escape} in xstring")
+        assert_newline_offsets_for("/#{escape}\n/", "#{escape} in regexp")
+        assert_newline_offsets_for("%Q{#{escape}\n}", "#{escape} in %Q")
+        assert_newline_offsets_for("%W[#{escape}\n]", "#{escape} in %W")
+        assert_newline_offsets_for("<<~H\n#{escape}\n\nH\n", "#{escape} in heredoc")
+        assert_newline_offsets_for("?#{escape}\n", "#{escape} in char literal")
+      end
+
+      # Combined meta + control escapes
+      assert_newline_offsets_for("\"\\M-\\C-\n\"", "\\M-\\C- in string")
+      assert_newline_offsets_for("\"\\M-\\c\n\"", "\\M-\\c in string")
+
+      # \r\n consumed inside escape context
+      assert_newline_offsets_for("\"\\C-\r\n\"", "\\C- with \\r\\n")
+    end
+
     private
 
     def assert_newline_offsets(fixture)
-      source = fixture.read
+      assert_newline_offsets_for(fixture.read)
+    end
 
+    def assert_newline_offsets_for(source, message = nil)
       expected = [0]
       source.b.scan("\n") { expected << $~.offset(0)[0] + 1 }
 
-      assert_equal expected, Prism.parse(source).source.offsets
+      assert_equal expected, Prism.parse(source).source.offsets, message
     end
   end
 end