AssertXPath.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2009 Red Hat Inc. and/or its affiliates and other contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * 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.jboss.arquillian.config.descriptor.impl;

import java.io.ByteArrayInputStream;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;
import org.junit.Assert;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Simple helper for Xpath related Assertions.
 *
 * @author <a href="mailto:aslak@redhat.com">Aslak Knutsen</a>
 * @version $Revision: $
 */
public final class AssertXPath {
    /**
     * Util class, should not be constructed.
     */
    private AssertXPath() {
    }

    /**
     * Assert that the specified XPath Expression resolves to the specified values.
     * <br/><br/>
     * Assertions:<br/>
     * "ExpectedValue count should match found Node count" <br/>
     * "XPath content should match expected value" <br/>
     *
     * @param xml
     *     The XML to assert against
     * @param expression
     *     XPath expression to extract
     * @param expectedValue
     *     The Expected values found by expression
     *
     * @throws Exception
     *     XML/XPath related parse exceptions
     */
    public static void assertXPath(String xml, String expression, Object... expectedValue)
        throws Exception {
        Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(
            new ByteArrayInputStream(xml.getBytes()));

        XPathExpression xPathExpression = XPathFactory.newInstance().newXPath().compile(expression);

        NodeList nodes = (NodeList) xPathExpression.evaluate(doc, XPathConstants.NODESET);
        Assert.assertEquals(
            "ExpectedValue count should match found Node count",
            expectedValue.length,
            nodes.getLength());

        for (int i = 0; i < nodes.getLength(); i++) {
            Node node = nodes.item(i);
            Assert.assertEquals(
                "XPath content should match expected value",
                String.valueOf(expectedValue[i]),
                node.getTextContent());
        }
    }
}