Consider registered converters using Row and RowDocument as source.

We now consider converters for RowDocument. Additionally, we reinstated conversion from R2DBC's Row type into entities as that converter functionality got lost during the converter revision.

Closes #1710

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplate.java

@@ -57,6 +57,7 @@ import org.springframework.data.r2dbc.mapping.event.AfterConvertCallback;
 import org.springframework.data.r2dbc.mapping.event.AfterSaveCallback;
 import org.springframework.data.r2dbc.mapping.event.BeforeConvertCallback;
 import org.springframework.data.r2dbc.mapping.event.BeforeSaveCallback;
+import org.springframework.data.relational.core.conversion.AbstractRelationalConverter;
 import org.springframework.data.relational.core.mapping.PersistentPropertyTranslator;
 import org.springframework.data.relational.core.mapping.RelationalPersistentEntity;
 import org.springframework.data.relational.core.mapping.RelationalPersistentProperty;
@@ -818,7 +819,13 @@ public class R2dbcEntityTemplate implements R2dbcEntityOperations, BeanFactoryAw
 
 		BiFunction<Row, RowMetadata, T> rowMapper;
 
-		if (simpleType) {
+		// Bridge-code: Consider Converter<Row, T> until we have fully migrated to RowDocument
+		if (converter instanceof AbstractRelationalConverter relationalConverter
+				&& relationalConverter.getConversions().hasCustomReadTarget(Row.class, entityType)) {
+
+			ConversionService conversionService = relationalConverter.getConversionService();
+			rowMapper = (row, rowMetadata) -> (T) conversionService.convert(row, entityType);
+		} else if (simpleType) {
 			rowMapper = dataAccessStrategy.getRowMapper(resultType);
 		} else {
 

spring-data-r2dbc/src/test/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplateUnitTests.java

@@ -21,6 +21,7 @@ import static org.springframework.data.relational.core.query.Criteria.*;
 
 import io.r2dbc.spi.Parameters;
 import io.r2dbc.spi.R2dbcType;
+import io.r2dbc.spi.Row;
 import io.r2dbc.spi.test.MockColumnMetadata;
 import io.r2dbc.spi.test.MockResult;
 import io.r2dbc.spi.test.MockRow;
@@ -62,6 +63,7 @@ import org.springframework.data.relational.core.query.Criteria;
 import org.springframework.data.relational.core.query.Query;
 import org.springframework.data.relational.core.query.Update;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
+import org.springframework.data.relational.domain.RowDocument;
 import org.springframework.lang.Nullable;
 import org.springframework.r2dbc.core.DatabaseClient;
 import org.springframework.r2dbc.core.Parameter;
@@ -88,7 +90,8 @@ public class R2dbcEntityTemplateUnitTests {
 		client = DatabaseClient.builder().connectionFactory(recorder)
 				.bindMarkers(PostgresDialect.INSTANCE.getBindMarkersFactory()).build();
 
-		R2dbcCustomConversions conversions = R2dbcCustomConversions.of(PostgresDialect.INSTANCE, new MoneyConverter());
+		R2dbcCustomConversions conversions = R2dbcCustomConversions.of(PostgresDialect.INSTANCE, new MoneyConverter(),
+				new RowConverter(), new RowDocumentConverter());
 
 		entityTemplate = new R2dbcEntityTemplate(client, PostgresDialect.INSTANCE,
 				new MappingR2dbcConverter(new R2dbcMappingContext(), conversions));
@@ -610,6 +613,42 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from(Parameters.in(R2dbcType.VARCHAR, "$$$")));
 	}
 
+	@Test // GH-1696
+	void shouldConsiderRowConverter() {
+
+		MockRowMetadata metadata = MockRowMetadata.builder()
+				.columnMetadata(MockColumnMetadata.builder().name("foo").type(R2dbcType.INTEGER).build())
+				.columnMetadata(MockColumnMetadata.builder().name("bar").type(R2dbcType.VARCHAR).build()).build();
+		MockResult result = MockResult.builder().row(MockRow.builder().identified("foo", Object.class, 42)
+				.identified("bar", String.class, "the-bar").metadata(metadata).build()).build();
+
+		recorder.addStubbing(s -> s.startsWith("SELECT"), result);
+
+		entityTemplate.select(MyRowToEntityType.class).all().as(StepVerifier::create) //
+				.assertNext(actual -> {
+					assertThat(actual.foo).isEqualTo(1); // converter-fixed value
+					assertThat(actual.bar).isEqualTo("the-bar"); // converted value
+				}).verifyComplete();
+	}
+
+	@Test // GH-1696
+	void shouldConsiderRowDocumentConverter() {
+
+		MockRowMetadata metadata = MockRowMetadata.builder()
+				.columnMetadata(MockColumnMetadata.builder().name("foo").type(R2dbcType.INTEGER).build())
+				.columnMetadata(MockColumnMetadata.builder().name("bar").type(R2dbcType.VARCHAR).build()).build();
+		MockResult result = MockResult.builder().row(MockRow.builder().identified("foo", Object.class, 42)
+				.identified("bar", Object.class, "the-bar").metadata(metadata).build()).build();
+
+		recorder.addStubbing(s -> s.startsWith("SELECT"), result);
+
+		entityTemplate.select(MyRowDocumentToEntityType.class).all().as(StepVerifier::create) //
+				.assertNext(actual -> {
+					assertThat(actual.foo).isEqualTo(1); // converter-fixed value
+					assertThat(actual.bar).isEqualTo("the-bar"); // converted value
+				}).verifyComplete();
+	}
+
 	record WithoutId(String name) {
 	}
 
@@ -825,4 +864,30 @@ public class R2dbcEntityTemplateUnitTests {
 		}
 
 	}
+
+	record MyRowToEntityType(int foo, String bar) {
+
+	}
+
+	static class RowConverter implements Converter<Row, MyRowToEntityType> {
+
+		@Override
+		public MyRowToEntityType convert(Row source) {
+			return new MyRowToEntityType(1, source.get("bar", String.class));
+		}
+
+	}
+
+	record MyRowDocumentToEntityType(int foo, String bar) {
+
+	}
+
+	static class RowDocumentConverter implements Converter<RowDocument, MyRowDocumentToEntityType> {
+
+		@Override
+		public MyRowDocumentToEntityType convert(RowDocument source) {
+			return new MyRowDocumentToEntityType(1, (String) source.get("bar"));
+		}
+
+	}
 }