Add comprehensive test coverage for Neo4jVectorFilterExpressionConverter (#3957)

Signed-off-by: Alex Klimenko <[email protected]>

Author: alxkm

vector-stores/spring-ai-neo4j-store/src/test/java/org/springframework/ai/vectorstore/neo4j/filter/Neo4jVectorFilterExpressionConverterTests.java

@@ -139,4 +139,115 @@ public void testComplexIdentifiers2() {
 			.isEqualTo("node.`metadata.author` IN [\"john\",\"jill\"] AND node.`metadata.'article_type'` = \"blog\"");
 	}
 
+	@Test
+	public void testEmptyList() {
+		// category IN []
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(IN, new Key("category"), new Value(List.of())));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.category` IN []");
+	}
+
+	@Test
+	public void testSingleItemList() {
+		// status IN ["active"]
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(IN, new Key("status"), new Value(List.of("active"))));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.status` IN [\"active\"]");
+	}
+
+	@Test
+	public void testNullValue() {
+		// description = null
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(EQ, new Key("description"), new Value(null)));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.description` = null");
+	}
+
+	@Test
+	public void testNestedJsonPath() {
+		// entity.profile.name = "EntityA"
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(EQ, new Key("entity.profile.name"), new Value("EntityA")));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.entity.profile.name` = \"EntityA\"");
+	}
+
+	@Test
+	public void testNumericStringValue() {
+		// id = "1"
+		String vectorExpr = this.converter.convertExpression(new Expression(EQ, new Key("id"), new Value("1")));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.id` = \"1\"");
+	}
+
+	@Test
+	public void testZeroValue() {
+		// count = 0
+		String vectorExpr = this.converter.convertExpression(new Expression(EQ, new Key("count"), new Value(0)));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.count` = 0");
+	}
+
+	@Test
+	public void testComplexNestedGroups() {
+		// ((fieldA >= 100 AND fieldB = "X1") OR (fieldA >= 50 AND fieldB = "Y2")) AND
+		// fieldC <> "inactive"
+		String vectorExpr = this.converter.convertExpression(new Expression(AND,
+				new Group(new Expression(OR,
+						new Group(new Expression(AND, new Expression(GTE, new Key("fieldA"), new Value(100)),
+								new Expression(EQ, new Key("fieldB"), new Value("X1")))),
+						new Group(new Expression(AND, new Expression(GTE, new Key("fieldA"), new Value(50)),
+								new Expression(EQ, new Key("fieldB"), new Value("Y2")))))),
+				new Expression(NE, new Key("fieldC"), new Value("inactive"))));
+
+		assertThat(vectorExpr).isEqualTo("((node.`metadata.fieldA` >= 100 AND node.`metadata.fieldB` = \"X1\") OR "
+				+ "(node.`metadata.fieldA` >= 50 AND node.`metadata.fieldB` = \"Y2\")) AND "
+				+ "node.`metadata.fieldC` <> \"inactive\"");
+	}
+
+	@Test
+	public void testMixedDataTypes() {
+		// active = true AND score >= 1.5 AND tags IN ["featured", "premium"] AND version
+		// = 1
+		String vectorExpr = this.converter.convertExpression(new Expression(AND,
+				new Expression(AND,
+						new Expression(AND, new Expression(EQ, new Key("active"), new Value(true)),
+								new Expression(GTE, new Key("score"), new Value(1.5))),
+						new Expression(IN, new Key("tags"), new Value(List.of("featured", "premium")))),
+				new Expression(EQ, new Key("version"), new Value(1))));
+
+		assertThat(vectorExpr).isEqualTo("node.`metadata.active` = true AND node.`metadata.score` >= 1.5 AND "
+				+ "node.`metadata.tags` IN [\"featured\",\"premium\"] AND node.`metadata.version` = 1");
+	}
+
+	@Test
+	public void testNinWithMixedTypes() {
+		// status NOT IN ["A", "B", "C"]
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(NIN, new Key("status"), new Value(List.of("A", "B", "C"))));
+		assertThat(vectorExpr).isEqualTo("NOT node.`metadata.status` IN [\"A\",\"B\",\"C\"]");
+	}
+
+	@Test
+	public void testEmptyStringValue() {
+		// description <> ""
+		String vectorExpr = this.converter.convertExpression(new Expression(NE, new Key("description"), new Value("")));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.description` <> \"\"");
+	}
+
+	@Test
+	public void testArrayIndexAccess() {
+		// tags[0] = "important"
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(EQ, new Key("tags[0]"), new Value("important")));
+		assertThat(vectorExpr).isEqualTo("node.`metadata.tags[0]` = \"important\"");
+	}
+
+	@Test
+	public void testNegativeNumbers() {
+		// valueA <= -5 AND valueB >= -10
+		String vectorExpr = this.converter
+			.convertExpression(new Expression(AND, new Expression(LTE, new Key("valueA"), new Value(-5)),
+					new Expression(GTE, new Key("valueB"), new Value(-10))));
+
+		assertThat(vectorExpr).isEqualTo("node.`metadata.valueA` <= -5 AND node.`metadata.valueB` >= -10");
+	}
+
 }