add failing test

Author: hmottestad

core/sail/memory/src/test/java/org/eclipse/rdf4j/sail/memory/MemoryStoreMinusScopingDebugTest.java

@@ -0,0 +1,130 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ ******************************************************************************/
+
+package org.eclipse.rdf4j.sail.memory;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.Arrays;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.eclipse.rdf4j.model.IRI;
+import org.eclipse.rdf4j.model.Value;
+import org.eclipse.rdf4j.query.BindingSet;
+import org.eclipse.rdf4j.query.QueryResults;
+import org.eclipse.rdf4j.query.TupleQuery;
+import org.eclipse.rdf4j.query.TupleQueryResult;
+import org.eclipse.rdf4j.repository.RepositoryConnection;
+import org.eclipse.rdf4j.repository.sail.SailRepository;
+import org.eclipse.rdf4j.repository.sail.SailRepositoryConnection;
+import org.eclipse.rdf4j.rio.RDFFormat;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Local duplicates of selected {@link org.eclipse.rdf4j.testsuite.sparql.tests.SparqlMinusScopingTests} cases to ease
+ * debugging against a concrete {@link MemoryStore} repository.
+ */
+public class MemoryStoreMinusScopingDebugTest {
+
+	private static final String PREFIX = "PREFIX : <http://ex/>\n";
+	private static final String DATA_BASE_IRI = "http://ex/";
+
+	private SailRepository repository;
+
+	@BeforeEach
+	public void setUp() {
+		repository = new SailRepository(new MemoryStore());
+		repository.init();
+	}
+
+	@AfterEach
+	public void tearDown() {
+		if (repository != null) {
+			repository.shutDown();
+		}
+	}
+
+	@Test
+	public void T16_rhs_bind_of_outer_var_produces_unbound_then_overremoves_on_shared_subset() throws IOException {
+		String ttl = "@prefix : <http://ex/> .\n" +
+				":a :p 1 ; :q 1, 2 .\n" +
+				":b :p 3 ; :q 4 .\n" +
+				":c :p 7 .";
+
+		try (SailRepositoryConnection conn = repository.getConnection()) {
+			List<BindingSet> rows = selectWithData(conn, ttl, RDFFormat.TURTLE,
+					"SELECT ?x WHERE {\n" +
+							"  ?x :p ?n .\n" +
+							"  MINUS { BIND(?n AS ?k) ?x :q ?k }\n" +
+							"} ORDER BY ?x");
+
+			assertEquals(setOf("c"), names(rows, "x"),
+					"RHS BIND on unbound outer var must not correlate; shared-vars logic should remove :a,:b only.");
+		}
+	}
+
+	@Test
+	public void T21_not_exists_over_optional_is_always_false_here() throws IOException {
+		String ttl = "@prefix : <http://ex/> .\n" +
+				":e :name \"Alice\" ; :formerName \"Alice\" .\n" +
+				":f :name \"Carol\" .";
+
+		try (SailRepositoryConnection conn = repository.getConnection()) {
+			List<BindingSet> rows = selectWithData(conn, ttl, RDFFormat.TURTLE,
+					"SELECT ?x WHERE {\n" +
+							"  ?x :name ?n .\n" +
+							"  FILTER NOT EXISTS { OPTIONAL { ?x :formerName ?n } }\n" +
+							"}");
+
+			assertEquals(List.of(), rows);
+		}
+	}
+
+	private List<BindingSet> selectWithData(RepositoryConnection conn, String data, RDFFormat format, String body)
+			throws IOException {
+		String sparql = PREFIX + body;
+
+		conn.clear();
+		conn.add(new StringReader(data), DATA_BASE_IRI, format);
+
+		TupleQuery query = conn.prepareTupleQuery(sparql);
+		try (TupleQueryResult result = query.evaluate()) {
+			return QueryResults.asList(result);
+		}
+	}
+
+	private static Set<String> names(List<BindingSet> rows, String var) {
+		return rows.stream()
+				.map(bs -> bs.getValue(var))
+				.filter(Objects::nonNull)
+				.map(MemoryStoreMinusScopingDebugTest::name)
+				.collect(Collectors.toCollection(LinkedHashSet::new));
+	}
+
+	private static String name(Value value) {
+		if (value instanceof IRI) {
+			return ((IRI) value).getLocalName();
+		}
+		return value.stringValue();
+	}
+
+	private static Set<String> setOf(String... values) {
+		return new LinkedHashSet<>(Arrays.asList(values));
+	}
+}