DATAREST-835 - Search resources returning a single resource now get and consider ETag and Last-Modified headers.

We now interpret If-None-Match and If-Modified-Since headers on requests to resources backed by query methods returning a single instance only. This allows clients to optimize GET requests to those resources to save bandwidth.

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/ResourceStatusUnitTests.java

@@ -0,0 +1,120 @@
+/*
+ * 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.rest.webmvc;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.mockito.Matchers.*;
+import static org.mockito.Mockito.*;
+
+import lombok.Value;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Matchers;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.data.annotation.Version;
+import org.springframework.data.keyvalue.core.mapping.KeyValuePersistentEntity;
+import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
+import org.springframework.data.rest.core.util.Supplier;
+import org.springframework.data.rest.webmvc.ResourceStatus.StatusAndHeaders;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+
+/**
+ * Unit tests for {@link ResourceStatus}.
+ * 
+ * @author Oliver Gierke
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class ResourceStatusUnitTests {
+
+	ResourceStatus status;
+	KeyValuePersistentEntity<?> entity;
+
+	@Mock HttpHeadersPreparer preparer;
+	@Mock Supplier<PersistentEntityResource> supplier;
+
+	@Before
+	public void setUp() {
+
+		this.status = ResourceStatus.of(preparer);
+
+		KeyValueMappingContext context = new KeyValueMappingContext();
+		this.entity = context.getPersistentEntity(Sample.class);
+
+		doReturn(new HttpHeaders()).when(preparer).prepareHeaders(eq(entity), Matchers.any());
+	}
+
+	/**
+	 * @see DATAREST-835
+	 */
+	@Test(expected = IllegalArgumentException.class)
+	public void rejectsNullPreparer() {
+		ResourceStatus.of(null);
+	}
+
+	/**
+	 * @see DATAREST-835
+	 */
+	@Test
+	public void returnsModifiedIfNoHeadersGiven() {
+		assertModified(status.getStatusAndHeaders(new HttpHeaders(), new Sample(0), entity));
+	}
+
+	/**
+	 * @see DATAREST-835
+	 */
+	@Test
+	public void returnsNotModifiedForEntityWithRequestedETag() {
+
+		HttpHeaders headers = new HttpHeaders();
+		headers.setIfNoneMatch("\"1\"");
+
+		assertNotModified(status.getStatusAndHeaders(headers, new Sample(1), entity));
+	}
+
+	/**
+	 * @see DATAREST-835
+	 */
+	@Test
+	public void returnsNotModifiedIfEntityIsStillConsideredValid() {
+
+		doReturn(true).when(preparer).isObjectStillValid(Matchers.any(), Matchers.any(HttpHeaders.class));
+
+		assertNotModified(status.getStatusAndHeaders(new HttpHeaders(), new Sample(0), entity));
+	}
+
+	private void assertModified(StatusAndHeaders statusAndHeaders) {
+
+		assertThat(statusAndHeaders.isModified(), is(true));
+		assertThat(statusAndHeaders.toResponseEntity(supplier).getStatusCode(), is(HttpStatus.OK));
+		verify(supplier).get();
+	}
+
+	private void assertNotModified(StatusAndHeaders statusAndHeaders) {
+
+		assertThat(statusAndHeaders.isModified(), is(false));
+		assertThat(statusAndHeaders.toResponseEntity(supplier).getStatusCode(), is(HttpStatus.NOT_MODIFIED));
+	}
+
+	@Value
+	static class Sample {
+		@Version int version;
+	}
+}