Fix failing Coherence test

Fixes #2850

Signed-off-by: Mark Pollack <[email protected]>

Author: markpollack

vector-stores/spring-ai-coherence-store/src/main/java/org/springframework/ai/vectorstore/coherence/CoherenceVectorStore.java

@@ -209,11 +209,12 @@ public List<Document> doSimilaritySearch(SearchRequest request) {
 			if (this.distanceType != DistanceType.COSINE || (1 - r.getDistance()) >= request.getSimilarityThreshold()) {
 				DocumentChunk.Id id = r.getKey();
 				DocumentChunk chunk = r.getValue();
-				chunk.metadata().put(DocumentMetadata.DISTANCE.value(), r.getDistance());
+				Map<String, Object> mergedMetadata = new HashMap<>(chunk.metadata());
+				mergedMetadata.put(DocumentMetadata.DISTANCE.value(), r.getDistance());
 				documents.add(Document.builder()
 					.id(id.docId())
 					.text(chunk.text())
-					.metadata(chunk.metadata())
+					.metadata(mergedMetadata)
 					.score(1 - r.getDistance())
 					.build());
 			}

vector-stores/spring-ai-coherence-store/src/test/java/org/springframework/ai/vectorstore/coherence/CoherenceVectorStoreIT.java

@@ -281,10 +281,15 @@ public void searchWithThreshold() {
 				.similarityThreshold(similarityThreshold)
 				.build());
 
+			// Debug: print all returned document IDs and metadata
+			for (Document doc : results) {
+				System.out.println("Returned doc ID: " + doc.getId() + ", metadata: " + doc.getMetadata());
+			}
+
 			assertThat(results).hasSize(1);
 			Document resultDoc = results.get(0);
 			assertThat(resultDoc.getId()).isEqualTo(this.documents.get(1).getId());
-			assertThat(resultDoc.getMetadata()).containsKeys("meta1", DocumentMetadata.DISTANCE.value());
+			assertThat(resultDoc.getMetadata()).containsKey(DocumentMetadata.DISTANCE.value());
 			assertThat(resultDoc.getScore()).isGreaterThanOrEqualTo(similarityThreshold);
 
 			truncateMap(context, ((CoherenceVectorStore) vectorStore).getMapName());
@@ -300,6 +305,22 @@ void getNativeClientTest() {
 		});
 	}
 
+	@Test
+	public void similaritySearchReturnsMetadata() {
+		this.contextRunner.run(context -> {
+			VectorStore vectorStore = context.getBean(VectorStore.class);
+			vectorStore.add(this.documents);
+
+			// Query that matches the first document, which has meta1
+			List<Document> results = vectorStore
+				.similaritySearch(SearchRequest.builder().query("spring ai").topK(1).build());
+
+			assertThat(results).hasSize(1);
+			Document resultDoc = results.get(0);
+			assertThat(resultDoc.getMetadata()).containsKeys("meta1", DocumentMetadata.DISTANCE.value());
+		});
+	}
+
 	private static boolean isSortedByDistance(final List<Document> documents) {
 		final List<Double> distances = documents.stream()
 			.map(doc -> (Double) doc.getMetadata().get(DocumentMetadata.DISTANCE.value()))