Fix failing tests

* consider nested descriptors
* old ruby compatibility

Author: valerauko

lib/onelogin/ruby-saml/idp_metadata_parser.rb

@@ -228,7 +228,8 @@ def idp_name_id_format
         # @return [String|nil] 'validUntil' attribute of metadata
         #
         def valid_until
-          @idpsso_descriptor.parent&.attributes&.[]('validUntil')
+          root = @idpsso_descriptor.root
+          root.attributes['validUntil'] if root && root.attributes
         end
 
         # @param binding_priority [Array]

test/idp_metadata_parser_test.rb

@@ -278,7 +278,7 @@ def initialize; end
       assert_equal "https://hello.example.com/access/saml/logout", parsed_metadata[:idp_slo_target_url]
       assert_equal "urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified", parsed_metadata[:name_identifier_format]
       assert_equal ["AuthToken", "SSOStartPage"], parsed_metadata[:idp_attribute_names]
-      assert_equal '2014-04-17T18:02:33.910Z', settings.valid_until
+      assert_equal '2014-04-17T18:02:33.910Z', parsed_metadata[:valid_until]
       assert_equal OpenSSL::SSL::VERIFY_PEER, @http.verify_mode
     end
 
@@ -352,10 +352,10 @@ def initialize; end
       settings = @idp_metadata_parser.parse_to_array(@idp_metadata)
       assert_equal "https://foo.example.com/access/saml/idp.xml", settings.first[:idp_entity_id]
       assert_equal "F1:3C:6B:80:90:5A:03:0E:6C:91:3E:5D:15:FA:DD:B0:16:45:48:72", settings.first[:idp_cert_fingerprint]
-      assert_equal '2014-04-17T18:02:33.910Z', settings.first.valid_until
+      assert_equal '2014-04-17T18:02:33.910Z', settings.first[:valid_until]
       assert_equal "https://bar.example.com/access/saml/idp.xml", settings.last[:idp_entity_id]
       assert_equal "08:EB:6E:60:A2:14:4E:89:EC:FA:05:74:9D:72:BF:5D:BE:54:F0:1A", settings.last[:idp_cert_fingerprint]
-      assert_equal '2014-04-17T18:02:33.910Z', settings.last.valid_until
+      assert_equal '2014-04-17T18:02:33.910Z', settings.last[:valid_until]
     end
   end