xpath: add a test for XPathParser#abbreviate

Author: kou

test/parser/test_xpath.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: false
+
+require "test/unit"
+require "rexml/parsers/xpathparser"
+
+module REXMLTests
+  class TestXPathParser < Test::Unit::TestCase
+    sub_test_case("#abbreviate") do
+      def abbreviate(xpath)
+        parser = REXML::Parsers::XPathParser.new
+        parser.abbreviate(xpath)
+      end
+
+      def test_document
+        assert_equal("/",
+                     abbreviate("/"))
+      end
+    end
+  end
+end