1 files changed, 24 insertions, 0 deletions
diff --git a/test/ripper/test_lexer.rb b/test/ripper/test_lexer.rb
new file mode 100644
index 0000000000..2ec66cd592
--- /dev/null
+++ b/test/ripper/test_lexer.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+begin
+  require_relative 'dummyparser'
+  require 'test/unit'
+  ripper_test = true
+  module TestRipper; end
+rescue LoadError
+end
+
+class TestRipper::Lexer < Test::Unit::TestCase
+  def test_nested_dedent_heredoc
+    bug = '[ruby-core:80977] [Bug #13536]'
+    str = <<~'E'
+    <<~"D"
+    #{
+    <<~"B"
+    this must be a valid ruby
+    B
+    }
+    D
+    E
+    assert_equal(str, Ripper.tokenize(str).join(""), bug)
+  end
+end