From 57bf603b7332db86c39680d16b78f94a904daf46 Mon Sep 17 00:00:00 2001
From: Bill Huang <bill.w.huang@oracle.com>
Date: Mon, 1 Aug 2022 16:37:22 +0000
Subject: [PATCH] 8289948: Improve test coverage for XPath functions: Node Set
 Functions

Reviewed-by: joehw
---
 .../jaxp/unittest/xpath/XPathAnyTypeTest.java |  20 +-
 .../unittest/xpath/XPathExpAnyTypeTest.java   |  14 +-
 .../unittest/xpath/XPathNodeSetFnTest.java    | 222 ++++++++++++++++++
 .../jaxp/unittest/xpath/XPathTestBase.java    | 133 ++++++++---
 4 files changed, 344 insertions(+), 45 deletions(-)
 create mode 100644 test/jaxp/javax/xml/jaxp/unittest/xpath/XPathNodeSetFnTest.java

diff --git a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathAnyTypeTest.java b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathAnyTypeTest.java
index 47b350f3532..27badf40864 100644
--- a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathAnyTypeTest.java
+++ b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathAnyTypeTest.java
@@ -90,7 +90,8 @@ public class XPathAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test04(XPath xpath, Document doc) throws XPathExpressionException {
-        boolean result1 = xpath.evaluateExpression("boolean(/Customers/Customer[@id=3])", doc, Boolean.class);
+        boolean result1 = xpath.evaluateExpression("boolean" +
+                "(/Customers/Customer[@id=\"x3\"])", doc, Boolean.class);
         assertTrue(result1);
     }
 
@@ -121,7 +122,8 @@ public class XPathAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test07(XPath xpath, Document doc) throws XPathExpressionException {
-        String result1 = xpath.evaluateExpression("string(/Customers/Customer[@id=3]/Phone/text())", doc, String.class);
+        String result1 = xpath.evaluateExpression("string(/Customers/Customer" +
+                "[@id=\"x3\"]/Phone/text())", doc, String.class);
         assertTrue(result1.equals("3333333333"));
     }
 
@@ -142,7 +144,8 @@ public class XPathAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test09(XPath xpath, Document doc) throws XPathExpressionException {
-        Node n = xpath.evaluateExpression("/Customers/Customer[@id=3]", doc, Node.class);
+        Node n = xpath.evaluateExpression("/Customers/Customer[@id=\"x3\"]",
+                doc, Node.class);
         assertEquals(n.getLocalName(), "Customer");
     }
 
@@ -151,7 +154,8 @@ public class XPathAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document", expectedExceptions = IllegalArgumentException.class)
     public void test10(XPath xpath, Document doc) throws XPathExpressionException {
-        File n = xpath.evaluateExpression("/Customers/Customer[@id=3]", doc, File.class);
+        File n = xpath.evaluateExpression("/Customers/Customer[@id=\"x3\"]",
+                doc, File.class);
     }
 
     /*
@@ -159,7 +163,8 @@ public class XPathAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test11(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathEvaluationResult<?> result = xpath.evaluateExpression("boolean(/Customers/Customer[@id=3])", doc);
+        XPathEvaluationResult<?> result = xpath.evaluateExpression(
+                "boolean(/Customers/Customer[@id=\"x3\"])", doc);
         verifyResult(result, true);
     }
 
@@ -178,7 +183,7 @@ public class XPathAnyTypeTest extends XPathTestBase {
     @Test(dataProvider = "document")
     public void test13(XPath xpath, Document doc) throws XPathExpressionException {
         XPathEvaluationResult<?> result = xpath.evaluateExpression(
-                "string(/Customers/Customer[@id=3]/Phone/text())", doc, XPathEvaluationResult.class);
+                "string(/Customers/Customer[@id=\"x3\"]/Phone/text())", doc, XPathEvaluationResult.class);
         verifyResult(result, "3333333333");
     }
 
@@ -196,7 +201,8 @@ public class XPathAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test15(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathEvaluationResult<?> result = xpath.evaluateExpression("/Customers/Customer[@id=3]", doc);
+        XPathEvaluationResult<?> result = xpath.evaluateExpression(
+                "/Customers/Customer[@id=\"x3\"]", doc);
         verifyResult(result, "Customer");
     }
 }
diff --git a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathExpAnyTypeTest.java b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathExpAnyTypeTest.java
index 4502083efa6..964d83d34f0 100644
--- a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathExpAnyTypeTest.java
+++ b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathExpAnyTypeTest.java
@@ -76,7 +76,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test04(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("boolean(/Customers/Customer[@id=3])");
+        XPathExpression exp = xpath.compile("boolean(/Customers/Customer[@id=\"x3\"])");
         boolean result1 = exp.evaluateExpression(doc, Boolean.class);
         assertTrue(result1);
     }
@@ -99,7 +99,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test06(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("string(/Customers/Customer[@id=3]/Phone/text())");
+        XPathExpression exp = xpath.compile("string(/Customers/Customer[@id=\"x3\"]/Phone/text())");
         String result1 = exp.evaluateExpression(doc, String.class);
         assertTrue(result1.equals("3333333333"));
     }
@@ -122,7 +122,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test08(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("/Customers/Customer[@id=3]");
+        XPathExpression exp = xpath.compile("/Customers/Customer[@id=\"x3\"]");
         Node n = exp.evaluateExpression(doc, Node.class);
         assertEquals(n.getLocalName(), "Customer");
     }
@@ -132,7 +132,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document", expectedExceptions = IllegalArgumentException.class)
     public void test09(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("/Customers/Customer[@id=3]");
+        XPathExpression exp = xpath.compile("/Customers/Customer[@id=\"x3\"]");
         File n = exp.evaluateExpression(doc, File.class);
     }
 
@@ -141,7 +141,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test10(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("boolean(/Customers/Customer[@id=3])");
+        XPathExpression exp = xpath.compile("boolean(/Customers/Customer[@id=\"x3\"])");
         XPathEvaluationResult<?> result = exp.evaluateExpression(doc);
         verifyResult(result, true);
     }
@@ -161,7 +161,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test12(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("string(/Customers/Customer[@id=3]/Phone/text())");
+        XPathExpression exp = xpath.compile("string(/Customers/Customer[@id=\"x3\"]/Phone/text())");
         XPathEvaluationResult<?> result = exp.evaluateExpression(doc, XPathEvaluationResult.class);
         verifyResult(result, "3333333333");
     }
@@ -181,7 +181,7 @@ public class XPathExpAnyTypeTest extends XPathTestBase {
      */
     @Test(dataProvider = "document")
     public void test14(XPath xpath, Document doc) throws XPathExpressionException {
-        XPathExpression exp = xpath.compile("/Customers/Customer[@id=3]");
+        XPathExpression exp = xpath.compile("/Customers/Customer[@id=\"x3\"]");
         XPathEvaluationResult<?> result = exp.evaluateExpression(doc);
         verifyResult(result, "Customer");
     }
diff --git a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathNodeSetFnTest.java b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathNodeSetFnTest.java
new file mode 100644
index 00000000000..b39378a90f6
--- /dev/null
+++ b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathNodeSetFnTest.java
@@ -0,0 +1,222 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package xpath;
+
+import org.testng.Assert;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+
+import javax.xml.xpath.*;
+
+/*
+ * @test
+ * @bug 8289948
+ * @library /javax/xml/jaxp/unittest
+ * @run testng xpath.XPathNodeSetFnTest
+ * @summary Tests the XPath Node Set Functions
+ */
+public class XPathNodeSetFnTest extends XPathTestBase {
+
+    private static final Document doc = getDtdDocument();
+
+    /*
+     * DataProvider for testing the id function.
+     * Data columns:
+     *  see parameters of the test "testIdFn"
+     */
+    @DataProvider(name = "idExpTestCases")
+    public Object[][] getIdExp() {
+        return new Object[][]{
+                {"id('x3')", "Customer_x3"},
+                {"id('x1 x2 x3')[3]", "Customer_x3"},
+                {"id('x1 | x2 | x3')[3]", "Customer_x3"},
+                {"id('x')", "Email_x"},
+                {"id(//Customer[3]/@id)", "Customer_x3"},
+                {"id(//*[.='123@xyz.com']/@id)", "Email_x"},
+        };
+    }
+
+    /*
+     * DataProvider for testing the count function.
+     * Data columns:
+     *  see parameters of the test "testCountFn"
+     */
+    @DataProvider(name = "countExpTestCases")
+    public Object[][] getCountExp() {
+        return new Object[][]{
+                {"count(//Customer)", CUSTOMERS},
+                {"count(//@id)", ID_ATTRIBUTES},
+                {"count(//Customer/@id)", CUSTOMERS},
+                {"count(//@*)", ID_ATTRIBUTES + FOO_ID_ATTRIBUTES},
+                {"count(//*)",
+                        ROOT + CUSTOMERS + FOO_CUSTOMERS +
+                                (CUSTOMERS + FOO_CUSTOMERS) *
+                                        CUSTOMER_ELEMENTS},
+                {"count(//*[@id])", ID_ATTRIBUTES},
+                {"count(./*)", ROOT},
+                {"count(//Customer[1]/following::*)",
+                        CUSTOMERS - 1 + FOO_CUSTOMERS +
+                                (CUSTOMERS - 1 + FOO_CUSTOMERS) *
+                                        CUSTOMER_ELEMENTS},
+                {"count(//Customer[1]/following-sibling::*)",
+                        CUSTOMERS - 1 + FOO_CUSTOMERS},
+                {"count(//Customer[3]/preceding::*)",
+                        CUSTOMERS - 1 + (CUSTOMERS - 1) * CUSTOMER_ELEMENTS},
+                {"count(//Customer[3]/preceding-sibling::*)", CUSTOMERS - 1},
+                {"count(//Customer[1]/ancestor::*)", ROOT},
+                {"count(//Customer[1]/ancestor-or-self::*)", ROOT + 1},
+                {"count(//Customer[1]/descendant::*)", CUSTOMER_ELEMENTS},
+                {"count(//Customer[1]/descendant-or-self::*)",
+                        CUSTOMER_ELEMENTS + 1},
+                {"count(//Customer/node())",
+                        ID_ATTRIBUTES + CUSTOMERS * CUSTOMER_ELEMENTS},
+        };
+    }
+
+    /*
+     * DataProvider for testing the position function.
+     * Data columns:
+     *  see parameters of the test "testPositionFn"
+     */
+    @DataProvider(name = "positionExpTestCases")
+    public Object[][] getPositionExp() {
+        return new Object[][]{
+                {"//Customer[position()=1]", "Customer_x1"},
+                {"//Customer[position()=last()]", "Customer_x3"},
+                {"//Customer[position()>1 and position()<last()]",
+                        "Customer_x2"},
+                {"//Customer[position() mod 2 =0]", "Customer_x2"},
+                {"//Customer[last()]", "Customer_x3"},
+        };
+    }
+
+    /*
+     * DataProvider for testing the name and local-name functions.
+     * Data columns:
+     *  see parameters of the test "testNameFn"
+     */
+    @DataProvider(name = "nameExpTestCases")
+    public Object[][] getNameExp() {
+        return new Object[][]{
+                {"local-name(//Customer)", "Customer"},
+                {"local-name(//foo:Customer)", "Customer"},
+                {"local-name(//Customer/@id)", "id"},
+                {"local-name(//foo:Customer/@foo:id)", "id"},
+                {"local-name(//*[local-name()='Customer'])", "Customer"},
+                {"namespace-uri(.)", ""},
+                {"namespace-uri(//Customers)", ""},
+                {"namespace-uri(//Customer)", ""},
+                {"namespace-uri(//foo:Customer)", "foo"},
+                {"namespace-uri(//@id)", ""},
+                {"namespace-uri(//@foo:id)", "foo"},
+                {"name(//*[namespace-uri()=\"foo\"])", "foo:Customer"},
+                {"name(//Customer)", "Customer"},
+                {"name(//foo:Customer)", "foo:Customer"},
+                {"name(//Customer/@id)", "id"},
+                {"name(//foo:Customer/@foo:id)", "foo:id"},
+                {"name(//*[name()='foo:Customer'])", "foo:Customer"},
+        };
+    }
+
+    /**
+     * Verifies that the result of evaluating the id function matches the
+     * expected result.
+     *
+     * @param exp      XPath expression
+     * @param expected expected result
+     * @throws Exception if test fails
+     */
+    @Test(dataProvider = "idExpTestCases")
+    void testIdFn(String exp, String expected) throws Exception {
+        XPath xPath = XPathFactory.newInstance().newXPath();
+
+        Node node = xPath.evaluateExpression(exp, doc, Node.class);
+        Node node2 = (Node) xPath.evaluate(exp, doc, XPathConstants.NODE);
+
+        Assert.assertEquals(node.getNodeName() + "_" +
+                        node.getAttributes().item(0).getNodeValue()
+                , expected);
+        Assert.assertEquals(node2, node);
+    }
+
+    /**
+     * Verifies that the result of evaluating the count function matches the
+     * expected result.
+     *
+     * @param exp      XPath expression
+     * @param expected expected result
+     * @throws Exception if test fails
+     */
+    @Test(dataProvider = "countExpTestCases")
+    void testCountFn(String exp, int expected) throws Exception {
+        XPath xPath = XPathFactory.newInstance().newXPath();
+
+        double num = xPath.evaluateExpression(exp, doc, Double.class);
+        double num2 = (double) xPath.evaluate(exp, doc, XPathConstants.NUMBER);
+
+        Assert.assertEquals(num, expected);
+        Assert.assertEquals(num2, num);
+    }
+
+    /**
+     * Verifies that the result of evaluating the position function matches the
+     * expected result.
+     *
+     * @param exp      XPath expression
+     * @param expected expected result
+     * @throws Exception if test fails
+     */
+    @Test(dataProvider = "positionExpTestCases")
+    void testPositionFn(String exp, String expected) throws Exception {
+        XPath xPath = XPathFactory.newInstance().newXPath();
+
+        Node node = xPath.evaluateExpression(exp, doc, Node.class);
+        Node node2 = (Node) xPath.evaluate(exp, doc, XPathConstants.NODE);
+
+        Assert.assertEquals(node.getNodeName() + "_" +
+                        node.getAttributes().item(0).getNodeValue()
+                , expected);
+        Assert.assertEquals(node2, node);
+    }
+
+    /**
+     * Verifies that the result of evaluating the name and local-name functions
+     * matches the expected result.
+     *
+     * @param exp      XPath expression
+     * @param expected expected result
+     * @throws Exception if test fails
+     */
+    @Test(dataProvider = "nameExpTestCases")
+    void testNameFn(String exp, String expected) throws Exception {
+        XPath xPath = XPathFactory.newInstance().newXPath();
+
+        String s = xPath.evaluateExpression(exp, doc, String.class);
+        String s2 = (String) xPath.evaluate(exp, doc, XPathConstants.STRING);
+
+        Assert.assertEquals(s, expected);
+        Assert.assertEquals(s2, s);
+    }
+}
diff --git a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathTestBase.java b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathTestBase.java
index 8ee45dec579..7481c2b6594 100644
--- a/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathTestBase.java
+++ b/test/jaxp/javax/xml/jaxp/unittest/xpath/XPathTestBase.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,11 +31,6 @@ import java.util.concurrent.atomic.AtomicLong;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathFactory;
-import static javax.xml.xpath.XPathConstants.BOOLEAN;
-import static javax.xml.xpath.XPathConstants.NUMBER;
-import static javax.xml.xpath.XPathConstants.STRING;
-import static javax.xml.xpath.XPathConstants.NODE;
-import static javax.xml.xpath.XPathConstants.NODESET;
 import javax.xml.xpath.XPathNodes;
 import javax.xml.xpath.XPathEvaluationResult;
 
@@ -51,42 +46,123 @@ import org.w3c.dom.Node;
  * Base class for XPath test
  */
 class XPathTestBase {
+    static final String DECLARATION = "<?xml version=\"1.0\" " +
+            "encoding=\"UTF-8\" standalone=\"yes\"?>";
 
-    static final String rawXML
-            = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>"
-            + "<Customers>"
-            + "    <Customer id=\"1\">"
+    static final String DTD = """
+            <!DOCTYPE Customers [
+               <!ELEMENT Customers (Customer*)>
+               <!ELEMENT Customer (Name, Phone, Email, Address)>
+               <!ELEMENT Name (#PCDATA)>
+               <!ELEMENT Phone (#PCDATA)>
+               <!ELEMENT Email (#PCDATA)>
+               <!ELEMENT Address (Street, City, State)>
+               <!ELEMENT Street (#PCDATA)>
+               <!ELEMENT City (#PCDATA)>
+               <!ELEMENT State (#PCDATA)>
+               <!ATTLIST Customer id ID #REQUIRED>
+               <!ATTLIST Email id ID #REQUIRED>
+            ]>
+
+            """;
+
+    static final String RAW_XML
+            = "<Customers xmlns:foo=\"foo\">"
+            + "    <Customer id=\"x1\">"
             + "        <Name>name1</Name>"
             + "        <Phone>1111111111</Phone>"
-            + "        <Email>123@xyz.com</Email>"
+            + "        <Email id=\"x\">123@xyz.com</Email>"
             + "        <Address>"
             + "            <Street>1111 111st ave</Street>"
             + "            <City>The City</City>"
             + "            <State>The State</State>"
             + "        </Address>"
             + "    </Customer>"
-            + "    <Customer id=\"2\">"
-            + "        <Name>name1</Name>"
+            + "    <Customer id=\"x2\">"
+            + "        <Name>name2</Name>"
             + "        <Phone>2222222222</Phone>"
-            + "        <Email>123@xyz.com</Email>"
+            + "        <Email id=\"y\">123@xyz.com</Email>"
             + "        <Address>"
             + "            <Street>2222 222nd ave</Street>"
             + "            <City>The City</City>"
             + "            <State>The State</State>"
             + "        </Address>"
             + "    </Customer>"
-            + "    <Customer id=\"3\">"
-            + "        <Name>name1</Name>"
+            + "    <Customer id=\"x3\">"
+            + "        <Name>name3</Name>"
             + "        <Phone>3333333333</Phone>"
-            + "        <Email>123@xyz.com</Email>"
+            + "        <Email id=\"z\">123@xyz.com</Email>"
             + "        <Address>"
             + "            <Street>3333 333rd ave</Street>"
             + "            <City>The City</City>"
             + "            <State>The State</State>"
             + "        </Address>"
             + "    </Customer>"
+            + "    <foo:Customer foo:id=\"x1\">"
+            + "        <foo:Name>name1</foo:Name>"
+            + "        <foo:Phone>1111111111</foo:Phone>"
+            + "        <foo:Email foo:id=\"x\">123@xyz.com</foo:Email>"
+            + "        <foo:Address>"
+            + "            <foo:Street>1111 111st ave</foo:Street>"
+            + "            <foo:City>The City</foo:City>"
+            + "            <foo:State>The State</foo:State>"
+            + "        </foo:Address>"
+            + "    </foo:Customer>"
             + "</Customers>";
 
+    // Number of root element.
+    final int ROOT = 1;
+    // Number of Customer elements.
+    final int CUSTOMERS = 3;
+    // Number of id attributes.
+    final int ID_ATTRIBUTES = 6;
+    // Number of child elements of Customer.
+    final int CUSTOMER_ELEMENTS = 7;
+    // Number of Customer in the foo namespace.
+    final int FOO_CUSTOMERS = 1;
+    // Number of id attributes in the foo namespace.
+    final int FOO_ID_ATTRIBUTES = 2;
+
+    /**
+     * Returns a {@link org.w3c.dom.Document} for XML with DTD.
+     * @return a DOM Document
+     * @throws RuntimeException if any error occurred during document
+     *  initialization.
+     */
+    public static Document getDtdDocument() throws RuntimeException {
+        return documentOf(DECLARATION + DTD + RAW_XML);
+    }
+
+    /**
+     * Returns a {@link org.w3c.dom.Document} for raw XML.
+     * @return a DOM Document
+     * @throws RuntimeException if any error occurred during document
+     *  initialization.
+     */
+    public static Document getDocument() throws RuntimeException {
+        return documentOf(DECLARATION + RAW_XML);
+    }
+
+    /**
+     * Returns a {@link org.w3c.dom.Document} for input XML string.
+     * @param xml the input xml string.
+     * @return a DOM Document.
+     * @throws RuntimeException if any error occurred during document
+     *  initialization.
+     */
+    public static Document documentOf(String xml) throws RuntimeException {
+        try {
+            var dBF = DocumentBuilderFactory.newInstance();
+            dBF.setValidating(false);
+            dBF.setNamespaceAware(true);
+            return dBF.newDocumentBuilder().parse(
+                    new ByteArrayInputStream(xml.getBytes("UTF-8")));
+        } catch (Exception e) {
+            System.out.println("Exception while initializing XML document");
+            throw new RuntimeException(e.getMessage());
+        }
+    }
+
     void verifyResult(XPathEvaluationResult<?> result, Object expected) {
         switch (result.type()) {
             case BOOLEAN:
@@ -126,13 +202,13 @@ class XPathTestBase {
     public Object[][] getInvalidNumericTypes() {
         XPath xpath = XPathFactory.newInstance().newXPath();
         return new Object[][]{{xpath, AtomicInteger.class},
-            {xpath, AtomicInteger.class},
-            {xpath, AtomicLong.class},
-            {xpath, BigDecimal.class},
-            {xpath, BigInteger.class},
-            {xpath, Byte.class},
-            {xpath, Float.class},
-            {xpath, Short.class}
+                {xpath, AtomicInteger.class},
+                {xpath, AtomicLong.class},
+                {xpath, BigDecimal.class},
+                {xpath, BigInteger.class},
+                {xpath, Byte.class},
+                {xpath, Float.class},
+                {xpath, Short.class}
         };
     }
 
@@ -140,13 +216,8 @@ class XPathTestBase {
      * DataProvider: XPath and Document objects
      */
     @DataProvider(name = "document")
-    public Object[][] getDocument() throws Exception {
-        DocumentBuilderFactory dBF = DocumentBuilderFactory.newInstance();
-        dBF.setValidating(false);
-        dBF.setNamespaceAware(true);
-        Document doc = dBF.newDocumentBuilder().parse(
-                new ByteArrayInputStream(rawXML.getBytes("UTF-8")));
-
+    public Object[][] getDocuments() throws RuntimeException {
+        Document doc = getDocument();
         return new Object[][]{{XPathFactory.newInstance().newXPath(), doc}};
     }
 }