Add support for asserting JSON

Based on the JSONassert library.

Issue: SPR-10113

build.gradle

@@ -906,6 +906,7 @@ project("spring-test") {
 		optional("org.aspectj:aspectjweaver:${aspectjVersion}")
 		optional("org.hamcrest:hamcrest-core:1.3")
 		optional("com.jayway.jsonpath:json-path:0.9.0")
+		optional("org.skyscreamer:jsonassert:1.2.3")
 		optional("xmlunit:xmlunit:1.5")
 		testCompile(project(":spring-context-support"))
 		testCompile(project(":spring-oxm"))

spring-test/src/main/java/org/springframework/test/util/JsonExpectationsHelper.java

+/*
+ * Copyright 2002-2014 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.skyscreamer.jsonassert.JSONAssert;
+
+/**
+ * A helper class for assertions on JSON content.
+ *
+ * <p>Use of this class requires the <a
+ * href="http://jsonassert.skyscreamer.org/">JSONassert<a/> library.
+ *
+ * @author Sebastien Deleuze
+ * @since 4.1
+ */
+public class JsonExpectationsHelper {
+
+	/**
+	 * Parse the expected and actual strings as JSON and assert the two
+	 * are "similar" - i.e. they contain the same attribute-value pairs
+	 * regardless of order and formatting.
+	 *
+	 * @param expected the expected JSON content
+	 * @param actual the actual JSON content
+	 * @since 4.1
+	 */
+	public void assertJsonEqual(String expected, String actual) throws Exception {
+		JSONAssert.assertEquals(expected, actual, false);
+	}
+
+	/**
+	 * Parse the expected and actual strings as JSON and assert the two
+	 * are "not similar" - i.e. they contain different attribute-value pairs
+	 * regardless of order and formatting.
+	 *
+	 * @param expected the expected JSON content
+	 * @param actual the actual JSON content
+	 * @since 4.1
+	 */
+	public void assertJsonNotEqual(String expected, String actual) throws Exception {
+		JSONAssert.assertNotEquals(expected, actual, false);
+	}
+}

spring-test/src/main/java/org/springframework/test/web/servlet/result/ContentResultMatchers.java

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -28,6 +28,7 @@ import javax.xml.transform.dom.DOMSource;
 
 import org.hamcrest.Matcher;
 import org.springframework.http.MediaType;
+import org.springframework.test.util.JsonExpectationsHelper;
 import org.springframework.test.util.XmlExpectationsHelper;
 import org.springframework.test.web.servlet.MvcResult;
 import org.springframework.test.web.servlet.ResultMatcher;
@@ -44,6 +45,8 @@ public class ContentResultMatchers {
 
 	private final XmlExpectationsHelper xmlHelper;
 
+	private final JsonExpectationsHelper jsonHelper;
+
 
 	/**
 	 * Protected constructor.
@@ -51,6 +54,7 @@ public class ContentResultMatchers {
 	 */
 	protected ContentResultMatchers() {
 		this.xmlHelper = new XmlExpectationsHelper();
+		this.jsonHelper = new JsonExpectationsHelper();
 	}
 
 	/**
@@ -210,4 +214,26 @@ public class ContentResultMatchers {
 		};
 	}
 
+	/**
+	 * Parse the response content and the given string as JSON and assert the two
+	 * are "similar" - i.e. they contain the same attribute-value pairs
+	 * regardless of order and formatting.
+	 *
+	 * <p>Use of this matcher requires the <a
+	 * href="http://jsonassert.skyscreamer.org/">JSONassert<a/> library.
+	 *
+	 * @param jsonContent the expected JSON content
+	 * @since 4.1
+	 */
+	public ResultMatcher json(final String jsonContent) {
+		return new ResultMatcher() {
+
+			@Override
+			public void match(MvcResult result) throws Exception {
+				String content = result.getResponse().getContentAsString();
+				jsonHelper.assertJsonEqual(jsonContent, content);
+			}
+		};
+	}
+
 }

spring-test/src/test/java/org/springframework/test/web/servlet/result/ContentResultMatchersTests.java

 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -20,7 +20,6 @@ import org.hamcrest.Matchers;
 import org.junit.Test;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.test.web.servlet.StubMvcResult;
-import org.springframework.test.web.servlet.result.ContentResultMatchers;
 
 /**
  * @author Rossen Stoyanchev
@@ -78,6 +77,16 @@ public class ContentResultMatchersTests {
 		new ContentResultMatchers().bytes("bogus".getBytes()).match(getStubMvcResult());
 	}
 
+	@Test
+	public void json() throws Exception {
+		new ContentResultMatchers().json("{\n \"foo\" : \"bar\"         \n}").match(getStubMvcResult());
+	}
+
+	@Test(expected=AssertionError.class)
+	public void jsonNoMatch() throws Exception {
+		new ContentResultMatchers().json("{\n\"fooo\":\"bar\"\n}").match(getStubMvcResult());
+	}
+
 
 	private static final String CONTENT = "{\"foo\":\"bar\"}";