DATACMNS-983 - Added support for Javaslang and Vavr Try as method return types.

We now support the use of Vavr's Try as repository method return type so that exceptions caused by the repository method execution are wrapped into a Failure. Introduced a return type specific indirection of the execution. We now also recursively handle wrapper types so that Try<Option<…>> is valid, too.

Added support for Javaslang's Try, too.

src/test/java/org/springframework/data/repository/core/support/QueryExecutionResultHandlerUnitTests.java

@@ -17,6 +17,7 @@ package org.springframework.data.repository.core.support;
 
 import static org.assertj.core.api.Assertions.*;
 
+import io.vavr.control.Try;
 import javaslang.control.Option;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -35,7 +36,6 @@ import java.util.stream.Collectors;
 
 import org.junit.Test;
 import org.reactivestreams.Publisher;
-import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.util.Streamable;
@@ -345,23 +345,33 @@ public class QueryExecutionResultHandlerUnitTests {
 		Entity value = new Entity();
 		Optional<Entity> entity = Optional.of(value);
 
-		Object result = handler.postProcessInvocationResult(entity, TypeDescriptor.valueOf(Option.class));
+		Object result = handler.postProcessInvocationResult(entity, getMethod("option"));
 
 		assertThat(result).isInstanceOfSatisfying(Option.class, it -> assertThat(it.get()).isEqualTo(value));
 	}
 
 	@Test // DATACMNS-1165
 	@SuppressWarnings("unchecked")
-	public void convertsIterableIntoStreamable() {
+	public void convertsIterableIntoStreamable() throws Exception {
 
 		Iterable<?> source = Arrays.asList(new Object());
 
-		Object result = handler.postProcessInvocationResult(source, TypeDescriptor.valueOf(Streamable.class));
+		Object result = handler.postProcessInvocationResult(source, getMethod("streamable"));
 
 		assertThat(result).isInstanceOfSatisfying(Streamable.class,
 				it -> assertThat(it.stream().collect(Collectors.toList())).isEqualTo(source));
 	}
 
+	@Test // DATACMNS-938
+	public void resolvesNestedWrapperIfOuterDoesntNeedConversion() throws Exception {
+
+		Entity entity = new Entity();
+
+		Object result = handler.postProcessInvocationResult(entity, getMethod("tryOfOption"));
+
+		assertThat(result).isInstanceOfSatisfying(Option.class, it -> assertThat(it.get()).isEqualTo(entity));
+	}
+
 	private static Method getMethod(String methodName) throws Exception {
 		return Sample.class.getMethod(methodName);
 	}
@@ -387,6 +397,15 @@ public class QueryExecutionResultHandlerUnitTests {
 		Single<Entity> single();
 
 		Completable completable();
+
+		// DATACMNS-1056
+		Option<Entity> option();
+
+		// DATACMNS-1165
+		Streamable<Entity> streamable();
+
+		// DATACMNS-938
+		Try<Option<Entity>> tryOfOption();
 	}
 
 	static class Entity {}

src/test/java/org/springframework/data/repository/util/QueryExecutionConvertersUnitTests.java

@@ -22,6 +22,8 @@ import javaslang.collection.LinkedHashMap;
 import javaslang.collection.LinkedHashSet;
 import javaslang.collection.Seq;
 import javaslang.collection.Traversable;
+import javaslang.control.Try;
+import javaslang.control.Try.Failure;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import rx.Completable;
@@ -29,6 +31,7 @@ import rx.Observable;
 import rx.Single;
 import scala.Option;
 
+import java.io.IOException;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Collections;
@@ -361,8 +364,64 @@ public class QueryExecutionConvertersUnitTests {
 				.isEqualTo(ClassTypeInformation.from(String.class));
 	}
 
+	@Test // DATACMNS-983
+	public void exposesExecutionAdapterForJavaslangTry() throws Throwable {
+
+		Object result = getExecutionAdapter(Try.class).apply(() -> {
+			throw new IOException("Some message!");
+		});
+
+		assertThat(result).isInstanceOf(Failure.class);
+	}
+
+	@Test // DATACMNS-983
+	public void unwrapsDomainTypeFromJavaslangTryWrapper() throws Exception {
+
+		for (String methodName : Arrays.asList("tryMethod", "tryForSeqMethod")) {
+
+			Method method = Sample.class.getMethod(methodName);
+
+			TypeInformation<?> type = QueryExecutionConverters
+					.unwrapWrapperTypes(ClassTypeInformation.fromReturnTypeOf(method));
+
+			assertThat(type.getType()).isEqualTo(Sample.class);
+		}
+	}
+
+	@Test // DATACMNS-983
+	public void exposesExecutionAdapterForVavrTry() throws Throwable {
+
+		Object result = getExecutionAdapter(io.vavr.control.Try.class).apply(() -> {
+			throw new IOException("Some message!");
+		});
+
+		assertThat(result).isInstanceOf(io.vavr.control.Try.Failure.class);
+	}
+
+	@Test // DATACMNS-983
+	public void unwrapsDomainTypeFromVavrTryWrapper() throws Exception {
+
+		for (String methodName : Arrays.asList("tryMethod", "tryForSeqMethod")) {
+
+			Method method = Sample.class.getMethod(methodName);
+
+			TypeInformation<?> type = QueryExecutionConverters
+					.unwrapWrapperTypes(ClassTypeInformation.fromReturnTypeOf(method));
+
+			assertThat(type.getType()).isEqualTo(Sample.class);
+		}
+	}
+
 	interface Sample {
 
 		Page<String> pages();
+
+		Try<Sample> tryMethod();
+
+		Try<Seq<Sample>> tryForSeqMethod();
+
+		io.vavr.control.Try<Sample> vavrTryMethod();
+
+		io.vavr.control.Try<io.vavr.collection.Seq<Sample>> vavrTryForSeqMethod();
 	}
 }