[bugfix] Fix an issue with flattening Arrays and Lists when converting from Java types to XDM types

Author: adamretter

exist-core/pom.xml

@@ -759,6 +759,7 @@
                                 <include>src/test/resources-filtered/org/exist/xquery/JavaBindingTest.conf.xml</include>
                                 <include>src/test/java/org/exist/xquery/JavaBindingTest.java</include>
                                 <include>src/test/java/org/exist/xquery/WatchdogTest.java</include>
+                                <include>src/test/java/org/exist/xquery/XPathUtilTest.java</include>
                                 <include>src/main/java/org/exist/xquery/functions/fn/FunDocAvailable.java</include>
                                 <include>src/test/java/org/exist/xquery/functions/fn/FunXmlToJsonTest.java</include>
                                 <include>src/test/java/org/exist/xquery/functions/fn/ParsingFunctionsTest.java</include>
@@ -1753,6 +1754,7 @@
                                 <exclude>src/test/java/org/exist/xquery/XPathOpOrSpecialCaseTest.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/XPathQueryTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/XPathUtil.java</exclude>
+                                <exclude>src/test/java/org/exist/xquery/XPathUtilTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/XQueryContext.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/XQueryContextAttributesTest.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/XQueryFunctionsTest.java</exclude>

exist-core/src/main/java/org/exist/xquery/Context.java

@@ -534,7 +534,8 @@ public interface Context {
      * The value argument is converted into an XPath value (@see XPathUtil#javaObjectToXPath(Object)).
      *
      * @param qname the qualified name of the new variable. Any namespaces should have been declared before.
-     * @param value a Java object, representing the fixed value of the variable.
+     * @param value a Java object, representing the fixed value of the variable. A Java Array or List will
+     *              be interpreted as an XDM Sequence.
      *
      * @return the created Variable object.
      *

exist-core/src/main/java/org/exist/xquery/XPathUtil.java

@@ -49,6 +49,7 @@
 import java.math.BigInteger;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -605,7 +606,7 @@ public static final Sequence javaObjectToXPath(final Object obj, final XQueryCon
      * directly returned, other objects are converted into the corresponding
      * internal types.
      *
-     * @param obj The java object.
+     * @param obj The java object. A Java Array or List will be interpreted as an XDM Sequence.
      * @param context XQuery context.
      * @param expression the expression from which the object derives.
      *
@@ -641,7 +642,7 @@ public static final Sequence javaObjectToXPath(final Object obj, final XQueryCon
      * directly returned, other objects are converted into the corresponding
      * internal types.
      *
-     * @param obj The java object
+     * @param obj The java object. A Java Array or List will be interpreted as an XDM Sequence.
      * @param context XQuery context
      * @param expandChars true if characters should be expanded, false otherwise.
      * @param expression the expression from which the object derives.
@@ -662,8 +663,8 @@ public static final Sequence javaObjectToXPath(final Object obj, final XQueryCon
      * @param obj The java object.
      * @param context XQuery context.
      * @param expandChars true if characters should be expanded, false otherwise.
-     * @param listToSequence true if lists should be converted to sequences, false otherwise.
-     * @param arrayToSequence true if arrays should be converted to sequences, false otherwise.
+     * @param listToSequence true if Java Lists should be converted to sequences, false otherwise.
+     * @param arrayToSequence true if Java Arrays should be converted to sequences, false otherwise.
      * @param expression the expression from which the object derives.
      *
      * @return the XDM sequence.
@@ -741,21 +742,8 @@ public static final Sequence javaObjectToXPath(final Object obj, final XQueryCon
                 SerializerPool.getInstance().returnObject(streamer);
             }
 
-        } else if (listToSequence && obj instanceof List<?>) {
-            boolean createNodeSequence = true;
-
-            final List<?> lst = (List<?>) obj;
-            for (final Object next : lst) {
-                if (!(next instanceof NodeProxy)) {
-                    createNodeSequence = false;
-                    break;
-                }
-            }
-            final Sequence seq = createNodeSequence ? new AVLTreeNodeSet() : new ValueSequence(lst.size());
-            for (final Object o : lst) {
-                seq.add((Item) javaObjectToXPath(o, context, expandChars, listToSequence, arrayToSequence, expression));
-            }
-            return seq;
+        } else if (listToSequence && obj instanceof List<?> list) {
+            return javaArrayToXPath((List<Object>) list, context, expandChars, listToSequence, arrayToSequence, expression);
 
         } else if (obj instanceof NodeList) {
             context.pushDocumentContext();
@@ -786,20 +774,7 @@ public static final Sequence javaObjectToXPath(final Object obj, final XQueryCon
             }
 
         } else if (arrayToSequence && obj instanceof Object[] array) {
-            boolean createNodeSequence = true;
-            for (Object arrayItem : array) {
-                if (!(arrayItem instanceof NodeProxy)) {
-                    createNodeSequence = false;
-                    break;
-                }
-            }
-
-            final Sequence seq = createNodeSequence ? new AVLTreeNodeSet() : new ValueSequence();
-            for (final Object arrayItem : array) {
-                seq.add((Item) javaObjectToXPath(arrayItem, context, expandChars, listToSequence, arrayToSequence, expression));
-            }
-            return seq;
-
+            return javaArrayToXPath(Arrays.asList(array), context, expandChars, listToSequence, arrayToSequence, expression);
         }
 
         final int xdmType = javaClassToXdmType(obj.getClass());
@@ -906,6 +881,23 @@ public static final Sequence javaObjectToXPath(final Object obj, final XQueryCon
         }
     }
 
+    private static Sequence javaArrayToXPath(final Iterable<Object> objects, final XQueryContext context, final boolean expandChars, final boolean listToSequence, final boolean arrayToSequence, final Expression expression) throws XPathException {
+        boolean createNodeSequence = true;
+        for (final Object object : objects) {
+            if (!(object instanceof NodeProxy)) {
+                createNodeSequence = false;
+                break;
+            }
+        }
+
+        final Sequence result = createNodeSequence ? new AVLTreeNodeSet() : new ValueSequence();
+        for (final Object object : objects) {
+            final Sequence seq = javaObjectToXPath(object, context, expandChars, listToSequence, arrayToSequence, expression);
+            result.addAll(seq);
+        }
+        return result;
+    }
+
     /**
      * Converts an XMLResource into a NodeProxy.
      *

exist-core/src/test/java/org/exist/xquery/XPathUtilTest.java

@@ -0,0 +1,111 @@
+/*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+package org.exist.xquery;
+
+import org.exist.xquery.value.Sequence;
+import org.exist.xquery.value.Type;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.easymock.EasyMock.mock;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class XPathUtilTest {
+
+    @Test
+    public void listStringsToSequenceStrings() throws XPathException {
+        final XQueryContext mockContext = mock(XQueryContext.class);
+
+        final List<String> strings = Arrays.asList("hello", "goodbye");
+
+        replay(mockContext);
+        final Sequence result = XPathUtil.javaObjectToXPath(strings, mockContext);
+        assertEquals(strings.size(), result.getItemCount());
+        for (int i = 0; i < strings.size(); i++) {
+            assertEquals(Type.STRING, result.itemAt(i).getType());
+            assertEquals(strings.get(i), result.itemAt(i).getStringValue());
+        }
+        verify(mockContext);
+    }
+
+    @Test
+    public void arrayStringsToSequenceStrings() throws XPathException {
+        final XQueryContext mockContext = mock(XQueryContext.class);
+
+        final String[] strings = { "hello", "goodbye" };
+
+        replay(mockContext);
+        final Sequence result = XPathUtil.javaObjectToXPath(strings, mockContext);
+        assertEquals(strings.length, result.getItemCount());
+        for (int i = 0; i < strings.length; i++) {
+            assertEquals(Type.STRING, result.itemAt(i).getType());
+            assertEquals(strings[i], result.itemAt(i).getStringValue());
+        }
+        verify(mockContext);
+    }
+
+    @Test
+    public void listListStringsToSequenceStrings() throws XPathException {
+        final XQueryContext mockContext = mock(XQueryContext.class);
+
+        final List<List<String>> list = Arrays.asList(
+            List.of("hello"),
+            List.of("goodbye", "see you again soon")
+        );
+
+        replay(mockContext);
+        final Sequence result = XPathUtil.javaObjectToXPath(list, mockContext);
+        assertEquals(3, result.getItemCount());
+        for (int i = 0; i < list.size(); i++) {
+            final List<String> subList = list.get(i);
+            for (int j = 0; j < subList.size(); j++) {
+                assertEquals(Type.STRING, result.itemAt(i + j).getType());
+                assertEquals(subList.get(j), result.itemAt(i + j).getStringValue());
+            }
+        }
+        verify(mockContext);
+    }
+
+    @Test
+    public void arrayArrayStringsToSequenceStrings() throws XPathException {
+        final XQueryContext mockContext = mock(XQueryContext.class);
+
+        final Object[] array = new Object[2];
+        array[0] = new String[]{ "hello" };
+        array[1] = new String[]{ "goodbye", "see you again soon" };
+
+        replay(mockContext);
+        final Sequence result = XPathUtil.javaObjectToXPath(array, mockContext);
+        assertEquals(3, result.getItemCount());
+        for (int i = 0; i < array.length; i++) {
+            final String[] subArray = (String[]) array[i];
+            for (int j = 0; j < subArray.length; j++) {
+                assertEquals(Type.STRING, result.itemAt(i + j).getType());
+                assertEquals(subArray[j], result.itemAt(i + j).getStringValue());
+            }
+        }
+        verify(mockContext);
+    }
+}