Allow document ID to be other than String (#1534)

* fixes #1529

* add author

src/main/java/org/springframework/data/couchbase/core/convert/MappingCouchbaseConverter.java

@@ -81,6 +81,7 @@ import org.springframework.util.CollectionUtils;
  * @author Geoffrey Mina
  * @author Mark Paluch
  * @author Michael Reiche
+ * @author Remi Bleuse
  */
 public class MappingCouchbaseConverter extends AbstractCouchbaseConverter implements ApplicationContextAware {
 
@@ -955,7 +956,7 @@ public class MappingCouchbaseConverter extends AbstractCouchbaseConverter implem
 			Object value = expression != null ? evaluator.evaluate(expression) : source.get(property.getFieldName());
 
 			if (property == entity.getIdProperty() && parent == null) {
-				return (R) source.getId();
+				return readValue(source.getId(), property.getTypeInformation(), source);
 			}
 			if (value == null) {
 				return null;

src/test/java/org/springframework/data/couchbase/core/mapping/MappingCouchbaseConverterTests.java

@@ -686,6 +686,25 @@ public class MappingCouchbaseConverterTests {
 		assertThat(read.deleted.truncatedTo(ChronoUnit.MILLIS)).isEqualTo(deleted.truncatedTo(ChronoUnit.MILLIS));
 	}
 
+	@Test
+	void writesAndReadsIdAsUUID() {
+		String idAsString = "fc1cc4c4-b7ea-4cb4-b43a-3fb9f574d123";
+		UUID id = UUID.fromString(idAsString);
+		String otherAsString = "fc1cc4c4-b7ea-4cb4-b43a-3fb9f574d456";
+		UUID other = UUID.fromString(otherAsString);
+
+		UuidIdEntity entity = new UuidIdEntity(id, other);
+
+		CouchbaseDocument converted = new CouchbaseDocument();
+		converter.write(entity, converted);
+		assertThat(converted.getContent().get("other")).isEqualTo(otherAsString);
+		assertThat(converted.getId()).isEqualTo(idAsString);
+
+		UuidIdEntity read = converter.read(UuidIdEntity.class, converted);
+		assertThat(read.id).isEqualTo(id);
+		assertThat(read.other).isEqualTo(other);
+	}
+
 	@Test
 	void writesAndReadsNestedClass() {
 		CouchbaseDocument converted = new CouchbaseDocument();
@@ -946,6 +965,16 @@ public class MappingCouchbaseConverterTests {
 		}
 	}
 
+	static class UuidIdEntity {
+		@Id private UUID id;
+		private UUID other;
+
+		public UuidIdEntity(UUID id, UUID other) {
+			this.id = id;
+			this.other = other;
+		}
+	}
+
 	@Test
 	void idNotGenerated() {
 		class Entity {