Add tests to demonstrate the problem

Author: vnickolov

algo/src/test/java/org/neo4j/gds/similarity/JaccardSimilarityTest.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.gds.similarity;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class JaccardSimilarityTest {
+
+    @ParameterizedTest(name = "{2}")
+    @MethodSource("listCollectors")
+    void shouldPassAtAllCasesOfListInput(
+        Collector<Number, ?, List<Number>> firstListCollector,
+        Collector<Number, ?, List<Number>> secondListCollector,
+        String label
+    ) {
+        var arr1 = new int[]{1,2,3};
+        var arr2 = new int[]{1,2,3};
+        List<Number> l1 = Arrays.stream(arr1).boxed().collect(firstListCollector);
+        List<Number> l2 = Arrays.stream(arr2).boxed().collect(secondListCollector);
+
+        var similarities = new SimilaritiesFunc();
+        var jaccarded = similarities.jaccardSimilarity(l1, l2);
+        assertThat(jaccarded).isEqualTo(1);
+    }
+
+    private static Stream<Arguments> listCollectors() {
+        return Stream.of(
+            Arguments.of(
+                Collectors.toUnmodifiableList(), Collectors.toUnmodifiableList(), "Unmodifiable, Unmodifiable"
+            ),
+            Arguments.of(
+                Collectors.toUnmodifiableList(), Collectors.toList(), "Unmodifiable, Modifiable"
+            ),
+            Arguments.of(
+                Collectors.toList(), Collectors.toList(), "Modifiable, Modifiable"
+            ),
+            Arguments.of(
+                Collectors.toList(), Collectors.toUnmodifiableList(), "Modifiable, Unmodifiable"
+            )
+        );
+    }
+
+}

algo/src/test/java/org/neo4j/gds/similarity/JaccardWithCypherTest.java

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+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.gds.similarity;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.neo4j.gds.BaseTest;
+import org.neo4j.gds.compat.GraphDatabaseApiProxy;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatNoException;
+import static org.assertj.core.api.InstanceOfAssertFactories.DOUBLE;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class JaccardWithCypherTest extends BaseTest {
+
+    @BeforeEach
+    void setUp() throws Exception {
+        GraphDatabaseApiProxy.registerFunctions(db, SimilaritiesFunc.class);
+    }
+
+    @Test
+    void testJaccardFunctionWithInputFromDatabase() {
+        assertThatNoException().isThrownBy(
+            () -> runQueryWithResultConsumer(
+                "CREATE (t:Test {listone: [1, 5], listtwo: [5, 5]}) RETURN gds.similarity.jaccard(t.listone, t.listtwo) AS score",
+                result -> {
+                    assertThat(result.hasNext()).isTrue();
+                    var score = result.next().get("score");
+                    assertThat(score)
+                        .asInstanceOf(DOUBLE)
+                        .isEqualTo(1.0 / 3.0);
+                }
+            )
+        );
+    }
+
+    @Test
+    void testJaccardFunction() {
+        assertThatNoException().isThrownBy(
+            () ->
+                runQueryWithResultConsumer(
+                    "RETURN gds.similarity.jaccard([1, 5], [5, 5]) AS score",
+                    result -> assertEquals(1.0 / 3.0, result.next().get("score"))
+                )
+        );
+    }
+}