test(qdrant): add test to verify Long metadata values are stored as String

Adds a test to ensure that Long values in document metadata are
safely converted to String before being stored in Qdrant.

The test inserts a document with a Long-type "ref_id", performs
a similarity search, and verifies that:
- the result is not empty,
- the retrieved "ref_id" is a String,
- the value matches the original Long when parsed.

Also ensures cleanup by deleting the inserted document from the store.

Author: solnone

vector-stores/spring-ai-qdrant-store/src/test/java/org/springframework/ai/vectorstore/qdrant/QdrantVectorStoreIT.java

@@ -314,6 +314,27 @@ void getNativeClientTest() {
 		});
 	}
 
+	@Test
+	void shouldConvertLongToString() {
+		this.contextRunner.run(context -> {
+			QdrantVectorStore vectorStore = context.getBean(QdrantVectorStore.class);
+			var refId = System.currentTimeMillis();
+			var doc = new Document("Long type ref_id", Map.of("ref_id", refId));
+			vectorStore.add(List.of(doc));
+
+			List<Document> results = vectorStore
+				.similaritySearch(SearchRequest.builder().query("Long type ref_id").topK(1).build());
+			assertThat(results).hasSize(1);
+			Document resultDoc = results.get(0);
+			var resultRefId = resultDoc.getMetadata().get("ref_id");
+			assertThat(resultRefId).isInstanceOf(String.class);
+			assertThat(Double.valueOf((String) resultRefId)).isEqualTo(refId);
+
+			// Remove all documents from the store
+			vectorStore.delete(List.of(resultDoc.getId()));
+		});
+	}
+
 	@SpringBootConfiguration
 	public static class TestApplication {