DATACMNS-853 - Added test case reproducing the issue.

Reproduce issue accessing persistent properties from interface-based entities using the ClassGeneratingPropertyAccessorFactory.

Related tickets: DATACMNS-809.
Original pull request: #161.
Related pull request: #160.

src/test/java/org/springframework/data/mapping/model/ClassGeneratingPropertyAccessorFactoryEntityTypeTests.java

@@ -0,0 +1,110 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.data.mapping.model;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+
+import java.io.Serializable;
+
+import org.junit.Test;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mapping.PersistentEntity;
+import org.springframework.data.mapping.context.SampleMappingContext;
+import org.springframework.data.mapping.context.SamplePersistentProperty;
+import org.springframework.data.repository.core.support.PersistentEntityInformation;
+
+/**
+ * Unit tests for {@link ClassGeneratingPropertyAccessorFactory} covering interface
+ * and concrete class entity types.
+ *
+ * @author John Blum
+ * @see DATACMNS-809
+ */
+public class ClassGeneratingPropertyAccessorFactoryEntityTypeTests {
+
+	private final SampleMappingContext mappingContext = new SampleMappingContext();
+
+	protected PersistentEntity<Object, SamplePersistentProperty> getPersistentEntity(Object entity) {
+		return getPersistentEntity(entity.getClass());
+	}
+
+	protected PersistentEntity<Object, SamplePersistentProperty> getPersistentEntity(Class<?> entityType) {
+		return mappingContext.getPersistentEntity(entityType);
+	}
+
+	protected PersistentEntityInformation<Object, ?> getPersistentEntityInformation(Object entity) {
+		return new PersistentEntityInformation<Object, Serializable>(getPersistentEntity(entity));
+	}
+
+	protected PersistentEntityInformation<Object, ?> getPersistentEntityInformation(Class<?> entityType) {
+		return new PersistentEntityInformation<Object, Serializable>(getPersistentEntity(entityType));
+	}
+
+	@Test
+	public void getIdentifierOfInterfaceBasedEntity() {
+		PersistentEntityInformation<Object, ?> quickSortEntityInfo =
+			getPersistentEntityInformation(Algorithm.class);
+
+		Algorithm quickSort = new QuickSort();
+
+		assertThat(String.valueOf(quickSortEntityInfo.getId(quickSort)), is(equalTo(quickSort.getName())));
+	}
+
+	@Test
+	public void getIdentifierOfClassBasedEntity() {
+		Person jonDoe = Person.newPerson("JonDoe");
+		PersistentEntityInformation<Object, ?> jonDoeEntityInfo = getPersistentEntityInformation(jonDoe);
+
+		assertThat(String.valueOf(jonDoeEntityInfo.getId(jonDoe)), is(equalTo(jonDoe.getName())));
+	}
+
+	interface Algorithm {
+		@Id String getName();
+	}
+
+	class QuickSort implements Algorithm {
+		@Override
+		public String getName() {
+			return getClass().toString();
+		}
+	}
+
+	static class Person {
+
+		@Id
+		private final String name;
+
+		static Person newPerson(String name) {
+			return new Person(name);
+		}
+
+		Person(String name) {
+			this.name = name;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		@Override
+		public String toString() {
+			return getName();
+		}
+	}
+}