[test] Add regression test for attribute eq with no range index (issue #3964)

extensions/indexes/range/src/test/java/org/exist/xquery/modules/range/AttributeEqIndexConsistencyTest.java

@@ -0,0 +1,204 @@
+/*
+ * eXist-db Open Source Native XML Database
+ * Copyright (C) 2001 The eXist-db Authors
+ *
+ * info@exist-db.org
+ * http://www.exist-db.org
+ *
+ * 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; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * 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.modules.range;
+
+import org.exist.EXistException;
+import org.exist.collections.Collection;
+import org.exist.collections.CollectionConfigurationException;
+import org.exist.collections.CollectionConfigurationManager;
+import org.exist.collections.triggers.TriggerException;
+import org.exist.security.PermissionDeniedException;
+import org.exist.storage.BrokerPool;
+import org.exist.storage.DBBroker;
+import org.exist.storage.lock.Lock;
+import org.exist.storage.txn.TransactionManager;
+import org.exist.storage.txn.Txn;
+import org.exist.test.ExistEmbeddedServer;
+import org.exist.util.LockException;
+import org.exist.util.MimeType;
+import org.exist.util.StringInputSource;
+import org.exist.xmldb.XmldbURI;
+import org.exist.xquery.XPathException;
+import org.exist.xquery.XQuery;
+import org.exist.xquery.XQueryContext;
+import org.exist.xquery.value.Sequence;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.xml.sax.SAXException;
+
+import java.io.IOException;
+import java.util.Optional;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Regression test for <a href="https://github.com/eXist-db/exist/issues/3964">#3964</a>:
+ * an attribute predicate {@code [@x eq 'val']} on a {@code collection(...)} step must return
+ * the same count as the explicit-string variant {@code [@x/string() eq 'val']}, regardless
+ * of whether a range index is defined on the attribute.
+ *
+ * <p>The issue reported that {@code @contrib-id-type eq 'jb-contributor-id'} returned 0
+ * results because the optimizer rewrote it to {@code range:eq(@contrib-id-type, ...)} when
+ * the range module was active, but no index was configured on the attribute itself. These
+ * tests exercise the rewrite path (the rewrite still happens — confirmed by AST inspection)
+ * and ensure the runtime fallback to the original {@code GeneralComparison} produces correct
+ * results.
+ */
+public class AttributeEqIndexConsistencyTest {
+
+    private static final String COLLECTION_NAME = "i3964-attr-eq-test";
+
+    /**
+     * Collection.xconf that defines a range index on an UNRELATED element ({@code <article-title>}),
+     * so the range index module is active for this collection but {@code @contrib-id-type} has no
+     * index. This mirrors the configuration in #3964 where the optimizer rewrote {@code @x eq 'val'}
+     * to {@code range:eq(@x, ...)} despite no matching index.
+     */
+    private static final String COLLECTION_CONFIG = """
+            <collection xmlns="http://exist-db.org/collection-config/1.0">
+                <index>
+                    <range>
+                        <create qname="article-title" type="xs:string"/>
+                    </range>
+                </index>
+            </collection>""";
+
+    private static final String SAMPLE_DOC = """
+            <article>
+                <front>
+                    <article-meta>
+                        <contrib-group>
+                            <contrib>
+                                <contrib-id contrib-id-type="jb-contributor-id">42</contrib-id>
+                            </contrib>
+                        </contrib-group>
+                    </article-meta>
+                </front>
+            </article>""";
+
+    private static final int DOC_COUNT = 5;
+
+    @ClassRule
+    public static final ExistEmbeddedServer existEmbeddedServer = new ExistEmbeddedServer(true, true);
+
+    private static XmldbURI collectionUri;
+
+    @BeforeClass
+    public static void setUp() throws EXistException, PermissionDeniedException, LockException,
+            TriggerException, SAXException, CollectionConfigurationException, IOException {
+        final BrokerPool pool = existEmbeddedServer.getBrokerPool();
+        collectionUri = XmldbURI.ROOT_COLLECTION_URI.append(COLLECTION_NAME);
+        try (final DBBroker broker = pool.get(Optional.of(pool.getSecurityManager().getSystemSubject()));
+             final Txn txn = pool.getTransactionManager().beginTransaction()) {
+            final Collection col = broker.getOrCreateCollection(txn, collectionUri);
+            broker.saveCollection(txn, col);
+
+            final CollectionConfigurationManager mgr = pool.getConfigurationManager();
+            mgr.addConfiguration(txn, broker, col, COLLECTION_CONFIG);
+
+            for (int i = 1; i <= DOC_COUNT; i++) {
+                broker.storeDocument(txn, XmldbURI.create("article-" + i + ".xml"),
+                        new StringInputSource(SAMPLE_DOC), MimeType.XML_TYPE, col);
+            }
+            broker.reindexCollection(txn, col.getURI());
+            pool.getTransactionManager().commit(txn);
+        }
+    }
+
+    @AfterClass
+    public static void tearDown() throws EXistException, PermissionDeniedException, LockException,
+            TriggerException, IOException {
+        if (collectionUri == null) {
+            return;
+        }
+        final BrokerPool pool = existEmbeddedServer.getBrokerPool();
+        final TransactionManager transact = pool.getTransactionManager();
+        try (final DBBroker broker = pool.get(Optional.of(pool.getSecurityManager().getSystemSubject()));
+             final Txn txn = transact.beginTransaction();
+             final Collection collection = broker.openCollection(collectionUri, Lock.LockMode.WRITE_LOCK)) {
+            if (collection != null) {
+                broker.removeCollection(txn, collection);
+            }
+            transact.commit(txn);
+        }
+    }
+
+    /**
+     * Reduced reproducer from issue #3964: both shapes must agree.
+     */
+    @Test
+    public void attributeEqMatchesStringEqOnCollectionWithoutIndex() throws EXistException, PermissionDeniedException, XPathException {
+        final long shapeA = count(
+                "collection('/db/" + COLLECTION_NAME + "')//contrib-id[@contrib-id-type eq 'jb-contributor-id']");
+        final long shapeB = count(
+                "collection('/db/" + COLLECTION_NAME + "')//contrib-id[@contrib-id-type/string() eq 'jb-contributor-id']");
+
+        assertEquals("Sanity: " + DOC_COUNT + " articles stored", DOC_COUNT, shapeB);
+        assertEquals(
+                "Shape A (@x eq 'val') must return the same count as Shape B (@x/string() eq 'val'); "
+                        + "issue #3964 — without this fix Shape A returned 0 because the optimizer rewrote "
+                        + "to range:eq even when no range index is configured.",
+                shapeB, shapeA);
+    }
+
+    /**
+     * Same check using {@code =} (general comparison).
+     */
+    @Test
+    public void attributeGeneralEqMatchesStringEqOnCollectionWithoutIndex() throws EXistException, PermissionDeniedException, XPathException {
+        final long shapeA = count(
+                "collection('/db/" + COLLECTION_NAME + "')//contrib-id[@contrib-id-type = 'jb-contributor-id']");
+        final long shapeB = count(
+                "collection('/db/" + COLLECTION_NAME + "')//contrib-id[@contrib-id-type/string() = 'jb-contributor-id']");
+
+        assertEquals("Sanity: " + DOC_COUNT + " articles stored", DOC_COUNT, shapeB);
+        assertEquals("Shape A (general '=') must agree with Shape B", shapeB, shapeA);
+    }
+
+    /**
+     * Same check via {@code fn:doc} — establishes the baseline that already worked in #3964
+     * and guards against regressing it.
+     */
+    @Test
+    public void attributeEqMatchesStringEqOnDocWithoutIndex() throws EXistException, PermissionDeniedException, XPathException {
+        final String docPath = "/db/" + COLLECTION_NAME + "/article-1.xml";
+        final long shapeA = count("doc('" + docPath + "')//contrib-id[@contrib-id-type eq 'jb-contributor-id']");
+        final long shapeB = count("doc('" + docPath + "')//contrib-id[@contrib-id-type/string() eq 'jb-contributor-id']");
+
+        assertEquals("Sanity: 1 contrib-id in one document", 1L, shapeB);
+        assertEquals("Shape A (doc) must agree with Shape B", shapeB, shapeA);
+    }
+
+    private long count(final String xpath) throws EXistException, PermissionDeniedException, XPathException {
+        final BrokerPool pool = existEmbeddedServer.getBrokerPool();
+        try (final DBBroker broker = pool.get(Optional.of(pool.getSecurityManager().getSystemSubject()))) {
+            final XQuery xquery = pool.getXQueryService();
+            final XQueryContext ctx = new XQueryContext(pool);
+            final Sequence result = xquery.execute(broker,
+                    xquery.compile(ctx, "declare option exist:optimize 'enable=yes'; count(" + xpath + ")"),
+                    null);
+            return ((org.exist.xquery.value.IntegerValue) result.itemAt(0)).getLong();
+        }
+    }
+}