From 58b992d99eaf277da7671e53c0a7fd3a65bd9534 Mon Sep 17 00:00:00 2001
From: cschaetzlein <christian.schaetzlein@bader-jene.de>
Date: Mon, 16 Nov 2015 16:15:04 +0100
Subject: [PATCH] Allow individual attributes in an XML element to be
 documented

Documenting an XML attribute in the XML payload leads to a
NullPointerException since no parent nodes exists for an XML
attribute. Rather than always trying to remove a node from its parent,
this commit changes the logic to apply special treament to nodes that
are attributes and remove the attribute from its owning element
instead.

Closes gh-167
---
 .../restdocs/payload/XmlContentHandler.java       | 11 ++++++++++-
 .../payload/ResponseFieldsSnippetTests.java       | 15 +++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/XmlContentHandler.java b/spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/XmlContentHandler.java
index a971f049..89b0aecf 100644
--- a/spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/XmlContentHandler.java
+++ b/spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/XmlContentHandler.java
@@ -34,6 +34,7 @@ import javax.xml.xpath.XPathExpression;
 import javax.xml.xpath.XPathExpressionException;
 import javax.xml.xpath.XPathFactory;
 
+import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
@@ -115,7 +116,15 @@ class XmlContentHandler implements ContentHandler {
 			}
 			for (int i = 0; i < matchingNodes.getLength(); i++) {
 				Node node = matchingNodes.item(i);
-				node.getParentNode().removeChild(node);
+
+				if (node.getNodeType() == Node.ATTRIBUTE_NODE) {
+					Attr attr = (Attr) node;
+					attr.getOwnerElement().removeAttributeNode(attr);
+				}
+				else {
+					node.getParentNode().removeChild(node);
+				}
+
 			}
 		}
 		if (payload.getChildNodes().getLength() > 0) {
diff --git a/spring-restdocs-core/src/test/java/org/springframework/restdocs/payload/ResponseFieldsSnippetTests.java b/spring-restdocs-core/src/test/java/org/springframework/restdocs/payload/ResponseFieldsSnippetTests.java
index 337e6e8c..72048301 100644
--- a/spring-restdocs-core/src/test/java/org/springframework/restdocs/payload/ResponseFieldsSnippetTests.java
+++ b/spring-restdocs-core/src/test/java/org/springframework/restdocs/payload/ResponseFieldsSnippetTests.java
@@ -192,6 +192,21 @@ public class ResponseFieldsSnippetTests {
 						.header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_XML_VALUE)
 						.build());
 	}
+	
+	@Test
+	public void undocumentedXmlWithAttributeResponseField() throws IOException {
+		this.thrown.expect(SnippetException.class);
+		this.thrown
+				.expectMessage(equalTo("The following parts of the payload were not"
+						+ " documented:\r\n<a>\r\n    <b>5</b>\r\n</a>\r\n"));
+		new ResponseFieldsSnippet(Arrays.asList(new FieldDescriptor("/a/b/@id").type("").description("")))
+				.document(new OperationBuilder("undocumented-xml-response-field",
+						this.snippet.getOutputDirectory())
+						.response()
+						.content("<a><b id=\"1\">5</b></a>")
+						.header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_XML_VALUE)
+						.build());
+	}
 
 	@Test
 	public void xmlResponseFieldWithNoType() throws IOException {