DATAREST-1458 - Fixed rendering of compact view to association resources.

The usage of text/uri-list as media type was entirely broken and not even advertised in the reference docs anymore. It's now again supported for both to-one and to-many associations via Collections. Maps are rejected as they cannot be rendered as list of URIs correctly. Updated reference documentation accordingly.

Added a custom MapModel implementation of RepresentationModel as apparently using Maps with EntityModel does not unwrap the content properly due to [0].

[0] https://github.com/FasterXML/jackson-databind/issues/171

spring-data-rest-tests/spring-data-rest-tests-core/src/test/java/org/springframework/data/rest/tests/TestMatchers.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.tests;
+
+import java.util.Arrays;
+
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
+import org.springframework.util.StringUtils;
+
+/**
+ * {@link Matcher} implementations useful in tests
+ *
+ * @author Oliver Drotbohm
+ */
+public class TestMatchers {
+
+	/**
+	 * Asserts that a {@link String} consists of a given number of lines.
+	 *
+	 * @param number
+	 * @return
+	 */
+	public static Matcher<String> hasNumberOfLines(int number) {
+
+		return new TypeSafeMatcher<String>(String.class) {
+
+			/*
+			 * (non-Javadoc)
+			 * @see org.hamcrest.SelfDescribing#describeTo(org.hamcrest.Description)
+			 */
+			@Override
+			public void describeTo(Description description) {
+				description.appendText("contains " + number + " lines");
+			}
+
+			/*
+			 * (non-Javadoc)
+			 * @see org.hamcrest.TypeSafeMatcher#describeMismatchSafely(java.lang.Object, org.hamcrest.Description)
+			 */
+			@Override
+			protected void describeMismatchSafely(String item, Description mismatchDescription) {
+
+				mismatchDescription.appendText(item) //
+						.appendText(" contains ") //
+						.appendValue(numberOfLines(item)) //
+						.appendText(" lines");
+			}
+
+			/*
+			 * (non-Javadoc)
+			 * @see org.hamcrest.TypeSafeMatcher#matchesSafely(java.lang.Object)
+			 */
+			@Override
+			protected boolean matchesSafely(String item) {
+				return numberOfLines(item) == number;
+			}
+
+			private long numberOfLines(String source) {
+
+				return Arrays.stream(source.split("\n")) //
+						.filter(StringUtils::hasText) //
+						.count();
+			}
+		};
+	}
+}

spring-data-rest-tests/spring-data-rest-tests-mongodb/src/main/java/org/springframework/data/rest/tests/mongodb/User.java

@@ -51,6 +51,8 @@ public class User {
 	public org.joda.time.LocalDateTime jodaDateTime;
 	public TypeWithPattern pattern;
 	public @DBRef(lazy = true) List<User> colleagues;
+	public @DBRef(lazy = true) User manager;
+	public @DBRef(lazy = true) Map<String, User> map;
 	public Map<String, Nested> colleaguesMap = new HashMap<String, Nested>();
 
 	public static class EmailAddress {

spring-data-rest-tests/spring-data-rest-tests-mongodb/src/test/java/org/springframework/data/rest/tests/mongodb/MongoWebTests.java

@@ -24,6 +24,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 import java.math.BigDecimal;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 
 import org.assertj.core.api.Condition;
 import org.junit.After;
@@ -31,6 +32,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.rest.tests.CommonWebTests;
+import org.springframework.data.rest.tests.TestMatchers;
 import org.springframework.data.rest.webmvc.RestMediaTypes;
 import org.springframework.data.rest.webmvc.support.RepositoryEntityLinks;
 import org.springframework.hateoas.IanaLinkRelations;
@@ -39,6 +41,7 @@ import org.springframework.hateoas.LinkRelation;
 import org.springframework.http.MediaType;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
 import org.springframework.web.util.UriComponentsBuilder;
 
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
@@ -54,6 +57,8 @@ import com.jayway.jsonpath.JsonPath;
 @ContextConfiguration(classes = MongoDbRepositoryConfig.class)
 public class MongoWebTests extends CommonWebTests {
 
+	private static final MediaType TEXT_URI_LIST = MediaType.parseMediaType("text/uri-list");
+
 	@Autowired ProfileRepository repository;
 	@Autowired UserRepository userRepository;
 	@Autowired RepositoryEntityLinks entityLinks;
@@ -86,15 +91,28 @@ public class MongoWebTests extends CommonWebTests {
 
 		userRepository.save(thomas);
 
+		User mark = new User();
+		mark.firstname = "Mark";
+		mark.lastname = "Paluch";
+		mark.colleagues = Arrays.asList(thomas);
+
+		userRepository.save(mark);
+
 		User oliver = new User();
 		oliver.firstname = "Oliver";
 		oliver.lastname = "Gierke";
 		oliver.address = address;
-		oliver.colleagues = Arrays.asList(thomas);
+		oliver.colleagues = Arrays.asList(thomas, mark);
 		userRepository.save(oliver);
 
-		thomas.colleagues = Arrays.asList(oliver);
+		thomas.manager = oliver;
+		thomas.colleagues = Arrays.asList(oliver, mark);
+		thomas.map = new HashMap<>();
+		thomas.map.put("oliver", oliver);
+		thomas.map.put("mark", mark);
+
 		userRepository.save(thomas);
+
 	}
 
 	@After
@@ -328,8 +346,8 @@ public class MongoWebTests extends CommonWebTests {
 		Profile profile = repository.findAll().iterator().next();
 
 		mvc.perform(get(link.expand(profile.getId()).getHref()))//
-				.andExpect(header().string("ETag", is("\"0\"")))//
-				.andExpect(header().string("Last-Modified", is(notNullValue())));
+				.andExpect(header().string(ETAG, is("\"0\"")))//
+				.andExpect(header().string(LAST_MODIFIED, is(notNullValue())));
 	}
 
 	@Test // DATAREST-835
@@ -340,7 +358,46 @@ public class MongoWebTests extends CommonWebTests {
 		Profile profile = repository.findAll().iterator().next();
 
 		mvc.perform(get(link.expand(profile.getType()).getHref()))//
-				.andExpect(header().string("ETag", is(nullValue())))//
-				.andExpect(header().string("Last-Modified", is(nullValue())));
+				.andExpect(header().string(ETAG, is(nullValue())))//
+				.andExpect(header().string(LAST_MODIFIED, is(nullValue())));
+	}
+
+	@Test // DATAREST-1458
+	public void accessCollectionAssociationResourceAsUriList() throws Exception {
+
+		Link usersLink = client.discoverUnique("users");
+		Link userLink = assertHasContentLinkWithRel(IanaLinkRelations.SELF, client.request(usersLink));
+		Link colleaguesLink = client.assertHasLinkWithRel("colleagues", client.request(userLink));
+
+		mvc.perform(get(colleaguesLink.expand().getHref()).accept(TEXT_URI_LIST)) //
+				.andExpect(status().isOk()) //
+				.andExpect(header().string(CONTENT_TYPE, is(TEXT_URI_LIST.toString()))) //
+				.andExpect(content().string(TestMatchers.hasNumberOfLines(2)));
+	}
+
+	@Test // DATAREST-1458
+	public void accessAssociationResourceAsUriList() throws Exception {
+
+		Link usersLink = client.discoverUnique("users");
+		Link userLink = assertHasContentLinkWithRel(IanaLinkRelations.SELF, client.request(usersLink));
+		Link managerLink = client.assertHasLinkWithRel("manager", client.request(userLink));
+
+		mvc.perform(get(managerLink.expand().getHref()).accept(TEXT_URI_LIST)) //
+				.andExpect(header().string(CONTENT_TYPE, is(TEXT_URI_LIST.toString()))) //
+				.andExpect(content().string(TestMatchers.hasNumberOfLines(1)));
+	}
+
+	@Test // DATAREST-1458
+	public void accessMapCollectionAssociationResourceAsUriList() throws Exception {
+
+		Link usersLink = client.discoverUnique("users");
+		Link userLink = assertHasContentLinkWithRel(IanaLinkRelations.SELF, client.request(usersLink));
+		Link mapLink = client.assertHasLinkWithRel("map", client.request(userLink));
+
+		mvc.perform(get(mapLink.expand().getHref())) //
+				.andDo(MockMvcResultHandlers.print());
+
+		mvc.perform(get(mapLink.expand().getHref()).accept(TEXT_URI_LIST)) //
+				.andExpect(status().isUnsupportedMediaType());
 	}
 }