Throw proper exception to invalid k-NN query

Signed-off-by: Junqiu Lei <[email protected]>

CHANGELOG.md

@@ -24,6 +24,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 * Allow nested knn field mapping when train model [#1318](https://github.com/opensearch-project/k-NN/pull/1318)
 * Properly designate model state for actively training models when nodes crash or leave cluster [#1317](https://github.com/opensearch-project/k-NN/pull/1317)
 * Fix script score queries not getting cached [#1367](https://github.com/opensearch-project/k-NN/pull/1367)
+* Throw proper exception to invalid k-NN query [#1380](https://github.com/opensearch-project/k-NN/pull/1380)
 ### Infrastructure
 * Upgrade gradle to 8.4 [1289](https://github.com/opensearch-project/k-NN/pull/1289)
 * Refactor security testing to install from individual components [#1307](https://github.com/opensearch-project/k-NN/pull/1307)

src/main/java/org/opensearch/knn/index/query/KNNQueryBuilder.java

@@ -100,8 +100,14 @@ public static void initialize(ModelDao modelDao) {
     }
 
     private static float[] ObjectsToFloats(List<Object> objs) {
+        if (Objects.isNull(objs)) {
+            throw new IllegalArgumentException("[" + NAME + "] requires 'vector' to be non-null");
+        }
         float[] vec = new float[objs.size()];
         for (int i = 0; i < objs.size(); i++) {
+            if (!(objs.get(i) instanceof Number)) {
+                throw new IllegalArgumentException("[" + NAME + "] requires 'vector' to be an array of numbers");
+            }
             vec[i] = ((Number) objs.get(i)).floatValue();
         }
         return vec;

src/test/java/org/opensearch/knn/index/VectorDataTypeIT.java

@@ -425,6 +425,51 @@ public void testKNNScriptScoreWithInvalidByteQueryVector() throws Exception {
         );
     }
 
+    @SneakyThrows
+    public void testSearchWithInvalidSearchVectorType() {
+        createKnnIndexMappingWithLuceneEngine(2, SpaceType.L2, VectorDataType.FLOAT.getValue());
+        ingestL2FloatTestData();
+        Request request = new Request("POST", String.format("/%s/_search", INDEX_NAME));
+        request.setJsonEntity(
+            "{\n"
+                + "  \"query\": {\n"
+                + "    \"knn\": {\n"
+                + "      \"test-field-vec-dt\": {\n"
+                + "        \"vector\": [\"a\", \"b\", \"c\", \"d\"],\n"
+                + "        \"k\": 4\n"
+                + "      }\n"
+                + "    }\n"
+                + "  }\n"
+                + "}"
+        );
+
+        ResponseException ex = expectThrows(ResponseException.class, () -> client().performRequest(request));
+        assertTrue(ex.getResponse().getStatusLine().getReasonPhrase().contains("Bad Request"));
+        assertTrue(ex.getMessage().contains(String.format(Locale.ROOT, "[knn] requires 'vector' to be an array of numbers")));
+    }
+
+    @SneakyThrows
+    public void testSearchWithMissingQueryVector() {
+        createKnnIndexMappingWithLuceneEngine(2, SpaceType.L2, VectorDataType.FLOAT.getValue());
+        ingestL2FloatTestData();
+        Request request = new Request("POST", String.format("/%s/_search", INDEX_NAME));
+        request.setJsonEntity(
+            "{\n"
+                + "  \"query\": {\n"
+                + "    \"knn\": {\n"
+                + "      \"test-field-vec-dt\": {\n"
+                + "        \"k\": 4\n"
+                + "      }\n"
+                + "    }\n"
+                + "  }\n"
+                + "}"
+        );
+
+        ResponseException ex = expectThrows(ResponseException.class, () -> client().performRequest(request));
+        assertTrue(ex.getResponse().getStatusLine().getReasonPhrase().contains("Bad Request"));
+        assertTrue(ex.getMessage().contains(String.format(Locale.ROOT, "[knn] requires 'vector' to be non-null")));
+    }
+
     @SneakyThrows
     private void ingestL2ByteTestData() {
         Byte[] b1 = { 6, 6 };

src/test/java/org/opensearch/knn/index/query/KNNQueryBuilderTests.java

@@ -127,6 +127,43 @@ public void testFromXcontent_WithFilter() throws Exception {
         actualBuilder.equals(knnQueryBuilder);
     }
 
+    public void testFromXContent_invalidQueryVectorType() throws Exception {
+        final ClusterService clusterService = mockClusterService(Version.CURRENT);
+
+        final KNNClusterUtil knnClusterUtil = KNNClusterUtil.instance();
+        knnClusterUtil.initialize(clusterService);
+
+        String[] invalidTypeQueryVector = { "a", "b", "c", "d" };
+
+        XContentBuilder builder = XContentFactory.jsonBuilder();
+        builder.startObject();
+        builder.startObject(FIELD_NAME);
+        builder.field(KNNQueryBuilder.VECTOR_FIELD.getPreferredName(), invalidTypeQueryVector);
+        builder.field(KNNQueryBuilder.K_FIELD.getPreferredName(), K);
+        builder.endObject();
+        builder.endObject();
+        XContentParser contentParser = createParser(builder);
+        contentParser.nextToken();
+        expectThrows(IllegalArgumentException.class, () -> KNNQueryBuilder.fromXContent(contentParser));
+    }
+
+    public void testFromXContent_missingQueryVector() throws Exception {
+        final ClusterService clusterService = mockClusterService(Version.CURRENT);
+
+        final KNNClusterUtil knnClusterUtil = KNNClusterUtil.instance();
+        knnClusterUtil.initialize(clusterService);
+
+        XContentBuilder builder = XContentFactory.jsonBuilder();
+        builder.startObject();
+        builder.startObject(FIELD_NAME);
+        builder.field(KNNQueryBuilder.K_FIELD.getPreferredName(), K);
+        builder.endObject();
+        builder.endObject();
+        XContentParser contentParser = createParser(builder);
+        contentParser.nextToken();
+        expectThrows(IllegalArgumentException.class, () -> KNNQueryBuilder.fromXContent(contentParser));
+    }
+
     @Override
     protected NamedXContentRegistry xContentRegistry() {
         List<NamedXContentRegistry.Entry> list = ClusterModule.getNamedXWriteables();