DATAREST-333, DATAREST-348 - OPTIONS requests now expose Accept-Patch header.

As recommended in RFC 5789, the support for PATCH request should be advertised in OPTIONS requests (already in place) and include an Accept-Patch header listing the patch media types supported. We now include the media types for JSON Patch, JSON Merge Patch and plain JSON in that header.

[0] http://tools.ietf.org/html/rfc5789#section-3

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryEntityController.java

@@ -19,6 +19,7 @@ import static org.springframework.http.HttpMethod.*;
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -53,6 +54,7 @@ import org.springframework.hateoas.UriTemplate;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.HttpRequestMethodNotSupportedException;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -68,6 +70,10 @@ import org.springframework.web.bind.annotation.ResponseBody;
 class RepositoryEntityController extends AbstractRepositoryRestController implements ApplicationEventPublisherAware {
 
 	private static final String BASE_MAPPING = "/{repository}";
+	private static final List<String> ACCEPT_PATCH_HEADERS = Arrays.asList(//
+			RestMediaTypes.MERGE_PATCH_JSON.toString(), //
+			RestMediaTypes.JSON_PATCH_JSON.toString(), //
+			MediaType.APPLICATION_JSON_VALUE);
 
 	private final RepositoryEntityLinks entityLinks;
 	private final RepositoryRestConfiguration config;
@@ -238,6 +244,7 @@ class RepositoryEntityController extends AbstractRepositoryRestController implem
 
 		HttpHeaders headers = new HttpHeaders();
 		headers.setAllow(information.getSupportedMethods(ResourceType.ITEM));
+		headers.put("Accept-Patch", ACCEPT_PATCH_HEADERS);
 
 		return new ResponseEntity<Object>(headers, HttpStatus.OK);
 	}

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

@@ -20,6 +20,8 @@ import static org.junit.Assert.*;
 import static org.springframework.data.rest.webmvc.WebTestUtils.*;
 import static org.springframework.http.HttpMethod.*;
 
+import java.util.List;
+
 import org.junit.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.mapping.context.PersistentEntities;
@@ -32,6 +34,7 @@ import org.springframework.data.rest.webmvc.jpa.Order;
 import org.springframework.data.rest.webmvc.jpa.Person;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.transaction.annotation.Transactional;
@@ -157,4 +160,21 @@ public class RepositoryEntityControllerIntegrationTests extends AbstractControll
 		HttpEntity<?> response = controller.optionsForItemResource(getResourceInformation(Person.class));
 		assertAllowHeaders(response, GET, PUT, PATCH, DELETE, HEAD, OPTIONS);
 	}
+
+	/**
+	 * @see DATAREST-333, DATAREST-348
+	 */
+	@Test
+	public void optionsForItermResourceSetsAllowPatchHeader() {
+
+		ResponseEntity<?> entity = controller.optionsForItemResource(getResourceInformation(Person.class));
+
+		List<String> value = entity.getHeaders().get("Accept-Patch");
+
+		assertThat(value, hasSize(3));
+		assertThat(value, hasItems(//
+				RestMediaTypes.JSON_PATCH_JSON.toString(), //
+				RestMediaTypes.MERGE_PATCH_JSON.toString(), //
+				MediaType.APPLICATION_JSON_VALUE));
+	}
 }