Fix fields wildcard support to vector tile search API (#85595) (#85615)

This commit changes the strategy on how fields are fetched by iterating over the returned map. In addition, the geo field is added the last one on the fields list so it does not get overridden.

docs/changelog/85595.yaml

@@ -0,0 +1,6 @@
+pr: 85595
+summary: Fix fields wildcard support to vector tile search API
+area: Geo
+type: bug
+issues:
+ - 85592

x-pack/plugin/vector-tile/src/javaRestTest/java/org/elasticsearch/xpack/vectortile/VectorTileRestIT.java

@@ -657,6 +657,36 @@ public void testWithFields() throws Exception {
         assertLayer(tile, META_LAYER, 4096, 1, 13);
     }
 
+    public void testWithNoExistingFields() throws Exception {
+        final Request mvtRequest = new Request(getHttpMethod(), INDEX_POLYGON + "/_mvt/location/" + z + "/" + x + "/" + y);
+        mvtRequest.setJsonEntity("{\"fields\": [\"otherField\"] }");
+        final VectorTile.Tile tile = execute(mvtRequest);
+        assertThat(tile.getLayersCount(), Matchers.equalTo(3));
+        assertLayer(tile, HITS_LAYER, 4096, 1, 2);
+        assertLayer(tile, AGGS_LAYER, 4096, 256 * 256, 2);
+        assertLayer(tile, META_LAYER, 4096, 1, 13);
+    }
+
+    public void testWithNullFields() throws Exception {
+        final Request mvtRequest = new Request(getHttpMethod(), INDEX_POLYGON + "/_mvt/location/" + z + "/" + x + "/" + y);
+        mvtRequest.setJsonEntity("{\"fields\": [\"nullField\"] }");
+        final VectorTile.Tile tile = execute(mvtRequest);
+        assertThat(tile.getLayersCount(), Matchers.equalTo(3));
+        assertLayer(tile, HITS_LAYER, 4096, 1, 2);
+        assertLayer(tile, AGGS_LAYER, 4096, 256 * 256, 2);
+        assertLayer(tile, META_LAYER, 4096, 1, 13);
+    }
+
+    public void testWithFieldsWildCard() throws Exception {
+        final Request mvtRequest = new Request(getHttpMethod(), INDEX_POLYGON + "/_mvt/location/" + z + "/" + x + "/" + y);
+        mvtRequest.setJsonEntity("{\"fields\": [\"*\"] }");
+        final VectorTile.Tile tile = execute(mvtRequest);
+        assertThat(tile.getLayersCount(), Matchers.equalTo(3));
+        assertLayer(tile, HITS_LAYER, 4096, 1, 5);
+        assertLayer(tile, AGGS_LAYER, 4096, 256 * 256, 2);
+        assertLayer(tile, META_LAYER, 4096, 1, 13);
+    }
+
     public void testSingleValueAgg() throws Exception {
         final Request mvtRequest = new Request(getHttpMethod(), INDEX_POLYGON + "/_mvt/location/" + z + "/" + x + "/" + y);
         mvtRequest.setJsonEntity(

x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/rest/RestVectorTileAction.java

@@ -51,6 +51,7 @@
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -180,15 +181,16 @@ private static SearchRequestBuilder searchRequestBuilder(RestCancellableNodeClie
         searchRequestBuilder.setSize(request.getSize());
         searchRequestBuilder.setFetchSource(false);
         searchRequestBuilder.setTrackTotalHitsUpTo(request.getTrackTotalHitsUpTo());
+        for (FieldAndFormat field : request.getFieldAndFormats()) {
+            searchRequestBuilder.addFetchField(field);
+        }
+        // added last in case there is a wildcard, the last one is picked
         searchRequestBuilder.addFetchField(
             new FieldAndFormat(
                 request.getField(),
                 "mvt(" + request.getZ() + "/" + request.getX() + "/" + request.getY() + "@" + request.getExtent() + ")"
             )
         );
-        for (FieldAndFormat field : request.getFieldAndFormats()) {
-            searchRequestBuilder.addFetchField(field);
-        }
         searchRequestBuilder.setRuntimeMappings(request.getRuntimeMappings());
         QueryBuilder qBuilder = QueryBuilders.geoShapeQuery(request.getField(), request.getBoundingBox());
         if (request.getQueryBuilder() != null) {
@@ -256,7 +258,6 @@ private static SearchRequestBuilder searchRequestBuilder(RestCancellableNodeClie
     @SuppressWarnings("unchecked")
     private static VectorTile.Tile.Layer.Builder buildHitsLayer(SearchHit[] hits, VectorTileRequest request) throws IOException {
         final VectorTile.Tile.Layer.Builder hitsLayerBuilder = VectorTileUtils.createLayerBuilder(HITS_LAYER, request.getExtent());
-        final List<FieldAndFormat> fields = request.getFieldAndFormats();
         final MvtLayerProps layerProps = new MvtLayerProps();
         final VectorTile.Tile.Feature.Builder featureBuilder = VectorTile.Tile.Feature.newBuilder();
         for (SearchHit searchHit : hits) {
@@ -269,12 +270,10 @@ private static VectorTile.Tile.Layer.Builder buildHitsLayer(SearchHit[] hits, Ve
                 featureBuilder.mergeFrom((byte[]) feature);
                 VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, ID_TAG, searchHit.getId());
                 VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, INDEX_TAG, searchHit.getIndex());
-                if (fields != null) {
-                    for (FieldAndFormat field : fields) {
-                        final DocumentField documentField = searchHit.field(field.field);
-                        if (documentField != null) {
-                            VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, field.field, documentField.getValue());
-                        }
+                final Map<String, DocumentField> fields = searchHit.getDocumentFields();
+                for (String field : fields.keySet()) {
+                    if (request.getField().equals(field) == false) {
+                        VectorTileUtils.addPropertyToFeature(featureBuilder, layerProps, field, fields.get(field).getValue());
                     }
                 }
                 hitsLayerBuilder.addFeatures(featureBuilder);