HSEARCH-2471 Added support for projections on unmapped fields with El…

…asticsearch

That's probably what was originally intended with the current code
handling projections of one-way bridged fields.

elasticsearch/src/main/java/org/hibernate/search/elasticsearch/impl/ElasticsearchHSQueryImpl.java

@@ -523,15 +523,17 @@ private FieldProjection createProjection(JsonBuilder.Array sourceFilterCollector
 			else {
 				// We check if it is a field created by a field bridge
 				BridgeDefinedField bridgeDefinedField = rootTypeMetadata.getBridgeDefinedFieldMetadataFor( projectedField );
-				if ( bridgeDefinedField == null ) {
+				if ( bridgeDefinedField != null ) {
+					return createProjection( sourceFilterCollector, rootTypeMetadata, bridgeDefinedField );
+				}
+				else {
 					/*
-					 * Don't fail immediately: this entity type may not be present in the results, in which case
-					 * we don't need to be able to project on this field for this exact entity type.
-					 * Just make sure we *will* ultimately fail if we encounter this entity type.
+					 * No metadata: fall back to dynamically converting the resulting
+					 * JSON to the most appropriate Java type.
 					 */
-					return new FailingUnknownFieldProjection( rootTypeMetadata, projectedField );
+					sourceFilterCollector.add( new JsonPrimitive( projectedField ) );
+					return new JsonDrivenProjection( projectedField );
 				}
-				return createProjection( sourceFilterCollector, rootTypeMetadata, bridgeDefinedField );
 			}
 		}
 
@@ -1046,27 +1048,6 @@ else if ( primitive.isString() ) {
 		}
 	}
 
-	/**
-	 * A projection used whenever a given type is missing a projected field.
-	 *
-	 * @author Yoann Rodiere
-	 */
-	private static class FailingUnknownFieldProjection extends FieldProjection {
-		private final TypeMetadata rootTypeMetadata;
-		private final String absoluteName;
-
-		public FailingUnknownFieldProjection(TypeMetadata rootTypeMetadata, String absoluteName) {
-			super();
-			this.rootTypeMetadata = rootTypeMetadata;
-			this.absoluteName = absoluteName;
-		}
-
-		@Override
-		public Object convertHit(JsonObject hit, ConversionContext conversionContext) {
-			throw LOG.unknownFieldForProjection( rootTypeMetadata.getType().getName(), absoluteName );
-		}
-	}
-
 	@Override
 	protected void extractFacetResults() {
 		SearchResult searchResult = getSearchResult();

elasticsearch/src/main/java/org/hibernate/search/elasticsearch/logging/impl/Log.java

@@ -123,11 +123,6 @@ BulkRequestFailedException elasticsearchBulkRequestFailed(String request, String
 	)
 	SearchException unexpectedNumericEncodingType(String fieldType, String fieldName);
 
-	@Message(id = ES_BACKEND_MESSAGES_START_ID + 19,
-			value = "Cannot project field '%2$s' for entity %1$s: unknown field"
-	)
-	SearchException unknownFieldForProjection(String entityType, String fieldName);
-
 	@Message(id = ES_BACKEND_MESSAGES_START_ID + 20,
 			value = "Could not create mapping for entity type %1$s"
 	)

elasticsearch/src/test/java/org/hibernate/search/elasticsearch/test/ElasticsearchClassBridgeIT.java

@@ -18,18 +18,23 @@
 import org.hibernate.search.FullTextSession;
 import org.hibernate.search.Search;
 import org.hibernate.search.elasticsearch.ElasticsearchQueries;
+import org.hibernate.search.elasticsearch.testutil.TestElasticsearchClient;
 import org.hibernate.search.query.engine.spi.QueryDescriptor;
 import org.hibernate.search.test.SearchTestBase;
 import org.hibernate.search.testsupport.TestForIssue;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 
 /**
  * @author Gunnar Morling
  */
 public class ElasticsearchClassBridgeIT extends SearchTestBase {
 
+	@Rule
+	public TestElasticsearchClient elasticsearchClient = new TestElasticsearchClient();
+
 	@Before
 	public void setupTestData() {
 		Session s = openSession();
@@ -136,6 +141,30 @@ public void testProjectionOnUnindexedClassBridgeField() {
 		s.close();
 	}
 
+	@Test
+	public void testProjectionOnUnknownBridgeField() throws Exception {
+		// Add an additional field to the ES mapping, unknown to Hibernate Search
+		elasticsearchClient.putMapping( "golfplayer", GolfPlayer.class, "{'properties': {'fieldNotInMapping': {'type':'integer'}}}" );
+		elasticsearchClient.index( "golfplayer", GolfPlayer.class, "9999", "{'id':9999,'fieldNotInMapping':42}" );
+
+		Session s = openSession();
+		FullTextSession session = Search.getFullTextSession( s );
+		Transaction tx = s.beginTransaction();
+
+		QueryDescriptor query = ElasticsearchQueries.fromQueryString( "fieldNotInMapping:42" );
+		List<?> result = session.createFullTextQuery( query, GolfPlayer.class )
+				.setProjection( "fieldNotInMapping" )
+				.list();
+
+		assertThat( result ).hasSize( 1 );
+
+		Object[] projection = (Object[]) result.iterator().next();
+		assertThat( ( (Number) projection[0] ).intValue() ).describedAs( "fieldNotInMapping" ).isEqualTo( 42 );
+
+		tx.commit();
+		s.close();
+	}
+
 	@Override
 	public Class<?>[] getAnnotatedClasses() {
 		return new Class[]{ GolfPlayer.class, GolfCourse.class, Hole.class };

elasticsearch/src/test/java/org/hibernate/search/elasticsearch/testutil/TestElasticsearchClient.java

@@ -32,6 +32,7 @@
 import io.searchbox.client.config.HttpClientConfig;
 import io.searchbox.cluster.Health;
 import io.searchbox.cluster.Health.Builder;
+import io.searchbox.core.Index;
 import io.searchbox.indices.CreateIndex;
 import io.searchbox.indices.DeleteIndex;
 import io.searchbox.indices.mapping.GetMapping;
@@ -56,10 +57,18 @@ public void putMapping(Class<?> mappedAndRootClass, String mappingJson) throws I
 		putMapping( mappedAndRootClass, mappedAndRootClass, mappingJson );
 	}
 
+	public void putMapping(String indexName, Class<?> mappedClass, String mappingJson) throws IOException {
+		putMapping( indexName, mappedClass.getName(), mappingJson );
+	}
+
 	public void putMapping(Class<?> rootClass, Class<?> mappedClass, String mappingJson) throws IOException {
 		putMapping( IndexNameNormalizer.getElasticsearchIndexName( rootClass.getName() ), mappedClass.getName(), mappingJson );
 	}
 
+	public String getMapping(String indexName, Class<?> mappedClass) throws IOException {
+		return getMapping( indexName, mappedClass.getName() );
+	}
+
 	public String getMapping(Class<?> mappedAndRootClass) throws IOException {
 		return getMapping( mappedAndRootClass, mappedAndRootClass );
 	}
@@ -107,12 +116,7 @@ protected String buildURI() {
 	}
 
 	public void putMapping(String indexName, String mappingName, String mappingJson) throws IOException {
-		/*
-		 * Convert to JsonElement first, so that some Elasticsearch peculiarities (such as the fact that
-		 * single quotes are not accepted as a substitute for single quotes) can be worked around.
-		 * In tests, single quotes are way easier to include in JSON strings, because we don't have to escape them.
-		 */
-		JsonElement mappingJsonElement = new JsonParser().parse( mappingJson );
+		JsonElement mappingJsonElement = toJsonElement( mappingJson );
 
 		JestResult result = client.execute( new PutMapping.Builder( indexName, mappingName, mappingJsonElement ).build() );
 		if ( !result.isSucceeded() ) {
@@ -142,6 +146,33 @@ public String getMapping(String indexName, String mappingName) throws IOExceptio
 		return mapping.toString();
 	}
 
+	public void index(String indexName, Class<?> mappedClass, String id, String jsonDocument) throws IOException {
+		index( indexName, mappedClass.getName(), id, jsonDocument );
+	}
+
+	public void index(Class<?> mappedAndRootClass, String id, String jsonDocument) throws IOException {
+		index( mappedAndRootClass, mappedAndRootClass, id, jsonDocument );
+	}
+
+	public void index(Class<?> rootClass, Class<?> mappedClass, String id, String jsonDocument) throws IOException {
+		index( IndexNameNormalizer.getElasticsearchIndexName( rootClass.getName() ), mappedClass.getName(), id, jsonDocument );
+	}
+
+	public void index(String indexName, String typeName, String id, String jsonDocument) throws IOException {
+		JsonElement documentJsonElement = toJsonElement( jsonDocument );
+
+		JestResult result = client.execute( new Index.Builder( documentJsonElement )
+				.index( indexName )
+				.type( typeName )
+				.id( id )
+				.refresh( true )
+				.build() );
+		if ( !result.isSucceeded() ) {
+			throw new AssertionFailure( "Error while indexing '" + jsonDocument
+					+ "' on index '" + indexName + "' for tests:" + result.getErrorMessage() );
+		}
+	}
+
 	@Override
 	protected void before() throws Throwable {
 		JestClientFactory factory = new JestClientFactory();
@@ -181,4 +212,13 @@ private void tryDeleteESIndex(String indexName) {
 		}
 	}
 
+	/*
+	 * Convert provided JSON to JsonElement, so that some Elasticsearch peculiarities (such as the fact that
+	 * single quotes are not accepted as a substitute for single quotes) can be worked around.
+	 * In tests, single quotes are way easier to include in JSON strings, because we don't have to escape them.
+	 */
+	private JsonElement toJsonElement(String jsonAsString) {
+		return new JsonParser().parse( jsonAsString );
+	}
+
 }