groovy methods for XPath assertions

gistfile1.groovy

    static final Map<String, String> NAMESPACES = [
            env: 'http://schemas.xmlsoap.org/soap/envelope/',
            xsd: 'http://www.w3.org/2001/XMLSchema',
            xsi: 'http://www.w3.org/2001/XMLSchema-instance'
    ]
    
    @Before
    void initXml() {
        evaluator = XPathFactory.newInstance().newXPath()
        evaluator.setNamespaceContext([
                getNamespaceURI: { prefix ->
                    NAMESPACES[prefix]
                }
        ] as NamespaceContext)

        def factory = DocumentBuilderFactory.newInstance()
        factory.namespaceAware = true
        builder = factory.newDocumentBuilder()
        assert builder.namespaceAware
    }
    
    def evalXpath(String xpath, String xml) {
        evalXpath(xpath, xml, XPathConstants.STRING)
    }

    def evalXpath(String xpath, String xml, QName resultType) {
        def rootElement = builder.parse(new ByteArrayInputStream(xml.bytes)).documentElement
        evaluator.evaluate(xpath, rootElement, resultType)
    }