Assert XML without considering order in XmlExpectationsHelper

This commit changes the `assertXmlEqual` implementation to compare
expected and actual XML documents without considering the order of XML
nodes.

Issue: SPR-15156

spring-test/src/test/java/org/springframework/test/util/XmlExpectationsHelperTests.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2002-2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.util;
+
+import org.hamcrest.Matchers;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+/**
+ * Unit tests for {@link XmlExpectationsHelper}.
+ *
+ * @author Matthew Depue
+ */
+public class XmlExpectationsHelperTests {
+
+	@Rule
+	public final ExpectedException exception = ExpectedException.none();
+
+
+	@Test
+	public void assertXmlEqualForEqual() throws Exception {
+		final String control = "<root><field1>f1</field1><field2>f2</field2></root>";
+		final String test = "<root><field1>f1</field1><field2>f2</field2></root>";
+
+		final XmlExpectationsHelper xmlHelper = new XmlExpectationsHelper();
+		xmlHelper.assertXmlEqual(control, test);
+	}
+
+	@Test
+	public void assertXmlEqualExceptionForIncorrectValue() throws Exception {
+		final String control = "<root><field1>f1</field1><field2>f2</field2></root>";
+		final String test = "<root><field1>notf1</field1><field2>f2</field2></root>";
+
+		exception.expect(AssertionError.class);
+		exception.expectMessage(Matchers.startsWith("Body content Expected child 'field1'"));
+
+		final XmlExpectationsHelper xmlHelper = new XmlExpectationsHelper();
+		xmlHelper.assertXmlEqual(control, test);
+	}
+
+	@Test
+	public void assertXmlEqualForOutOfOrder() throws Exception {
+		final String control = "<root><field1>f1</field1><field2>f2</field2></root>";
+		final String test = "<root><field2>f2</field2><field1>f1</field1></root>";
+
+		final XmlExpectationsHelper xmlHelper = new XmlExpectationsHelper();
+		xmlHelper.assertXmlEqual(control, test);
+	}
+
+	@Test
+	public void assertXmlEqualExceptionForMoreEntries() throws Exception {
+		final String control = "<root><field1>f1</field1><field2>f2</field2></root>";
+		final String test = "<root><field1>f1</field1><field2>f2</field2><field3>f3</field3></root>";
+
+		exception.expect(AssertionError.class);
+		exception.expectMessage(Matchers.containsString("Expected child nodelist length '2' but was '3'"));
+
+		final XmlExpectationsHelper xmlHelper = new XmlExpectationsHelper();
+		xmlHelper.assertXmlEqual(control, test);
+	}
+
+	@Test
+	public void assertXmlEqualExceptionForLessEntries() throws Exception {
+		final String control = "<root><field1>f1</field1><field2>f2</field2><field3>f3</field3></root>";
+		final String test = "<root><field1>f1</field1><field2>f2</field2></root>";
+
+		exception.expect(AssertionError.class);
+		exception.expectMessage(Matchers.containsString("Expected child nodelist length '3' but was '2'"));
+
+		final XmlExpectationsHelper xmlHelper = new XmlExpectationsHelper();
+		xmlHelper.assertXmlEqual(control, test);
+	}
+
+}