1 files changed, 129 insertions, 0 deletions

diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/LeftJoinTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/LeftJoinTest.java
new file mode 100644
index 00000000..6633b3b1
--- /dev/null
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/LeftJoinTest.java
@@ -0,0 +1,129 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package tools.refinery.store.query.interpreter;
+
+import org.junit.jupiter.api.Test;
+import tools.refinery.store.model.ModelStore;
+import tools.refinery.store.query.ModelQueryAdapter;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.term.int_.IntTerms;
+import tools.refinery.store.query.view.AnySymbolView;
+import tools.refinery.store.query.view.FunctionView;
+import tools.refinery.store.query.view.KeyOnlyView;
+import tools.refinery.store.representation.Symbol;
+import tools.refinery.store.tuple.Tuple;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertNullableResults;
+import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertResults;
+
+class LeftJoinTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Integer> age = Symbol.of("age", 1, Integer.class);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final FunctionView<Integer> ageView = new FunctionView<>(age);
+
+        @Test
+        void unarySymbolTest() {
+                var query = Query.of("Query", Integer.class, (builder, p1, output) -> builder
+                                .clause(
+                                                personView.call(p1),
+                                                output.assign(ageView.leftJoin(18, p1))
+                                ));
+
+                var store = ModelStore.builder()
+                                .symbols(person, age)
+                                .with(QueryInterpreterAdapter.builder()
+                                                .queries(query))
+                                .build();
+
+                var model = store.createEmptyModel();
+                var personInterpretation = model.getInterpretation(person);
+                var ageInterpretation = model.getInterpretation(age);
+                var queryEngine = model.getAdapter(ModelQueryAdapter.class);
+                var queryResultSet = queryEngine.getResultSet(query);
+
+                personInterpretation.put(Tuple.of(0), true);
+                personInterpretation.put(Tuple.of(1), true);
+                personInterpretation.put(Tuple.of(2), true);
+
+                ageInterpretation.put(Tuple.of(2), 24);
+
+                queryEngine.flushChanges();
+                assertNullableResults(Map.of(
+                                Tuple.of(0), Optional.of(18),
+                                Tuple.of(1), Optional.of(18),
+                                Tuple.of(2), Optional.of(24),
+                                Tuple.of(3), Optional.empty()
+                ), queryResultSet);
+
+                personInterpretation.put(Tuple.of(0), false);
+
+                ageInterpretation.put(Tuple.of(1), 20);
+                ageInterpretation.put(Tuple.of(2), null);
+
+                queryEngine.flushChanges();
+                assertNullableResults(Map.of(
+                                Tuple.of(0), Optional.empty(),
+                                Tuple.of(1), Optional.of(20),
+                                Tuple.of(2), Optional.of(18),
+                                Tuple.of(3), Optional.empty()
+                ), queryResultSet);
+        }
+
+        @Test
+        void unarySymbolWithAssignmentTest() {
+                // Tests an edge case where the outer joined variable is already bound in the query plan.
+                var query = Query.of("Query", (builder, p1) -> builder
+                                .clause(Integer.class, v1 -> List.of(
+                                                personView.call(p1),
+                                                v1.assign(IntTerms.constant(18)),
+                                                v1.assign(ageView.leftJoin(18, p1))
+                                )));
+
+                var store = ModelStore.builder()
+                                .symbols(person, age)
+                                .with(QueryInterpreterAdapter.builder()
+                                                .queries(query))
+                                .build();
+
+                var model = store.createEmptyModel();
+                var personInterpretation = model.getInterpretation(person);
+                var ageInterpretation = model.getInterpretation(age);
+                var queryEngine = model.getAdapter(ModelQueryAdapter.class);
+                var queryResultSet = queryEngine.getResultSet(query);
+
+                personInterpretation.put(Tuple.of(0), true);
+                personInterpretation.put(Tuple.of(1), true);
+                personInterpretation.put(Tuple.of(2), true);
+
+                ageInterpretation.put(Tuple.of(2), 24);
+
+                queryEngine.flushChanges();
+                assertResults(Map.of(
+                                Tuple.of(0), true,
+                                Tuple.of(1), true,
+                                Tuple.of(2), false,
+                                Tuple.of(3), false
+                ), queryResultSet);
+
+                personInterpretation.put(Tuple.of(0), false);
+
+                ageInterpretation.put(Tuple.of(1), 20);
+                ageInterpretation.put(Tuple.of(2), null);
+
+                queryEngine.flushChanges();
+                assertResults(Map.of(
+                                Tuple.of(0), false,
+                                Tuple.of(1), false,
+                                Tuple.of(2), true,
+                                Tuple.of(3), false
+                ), queryResultSet);
+        }
+}