EmbeddedWrappersUnitTest.java

/*
 * Copyright 2015 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.hateoas.core;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

import java.util.Collection;
import java.util.Collections;

import org.junit.Test;

/**
 * Unit tests for {@link EmbeddedWrappers}.
 * 
 * @author Oliver Gierke
 */
public class EmbeddedWrappersUnitTest {

	EmbeddedWrappers wrappers = new EmbeddedWrappers(false);

	/**
	 * @see #286
	 */
	@Test
	@SuppressWarnings("rawtypes")
	public void createsWrapperForEmptyCollection() {

		EmbeddedWrapper wrapper = wrappers.emptyCollectionOf(String.class);

		assertEmptyCollectionValue(wrapper);
		assertThat(wrapper.getRel(), is(nullValue()));
		assertThat(wrapper.getRelTargetType(), is(equalTo((Class) String.class)));
	}

	/**
	 * @see #286
	 */
	@Test
	public void createsWrapperForEmptyCollectionAndExplicitRel() {

		EmbeddedWrapper wrapper = wrappers.wrap(Collections.emptySet(), "rel");

		assertEmptyCollectionValue(wrapper);
		assertThat(wrapper.getRel(), is("rel"));
		assertThat(wrapper.getRelTargetType(), is(nullValue()));
	}

	/**
	 * @see #286
	 */
	@Test(expected = IllegalArgumentException.class)
	public void rejectsEmptyCollectionWithoutExplicitRel() {
		wrappers.wrap(Collections.emptySet());
	}

	private static void assertEmptyCollectionValue(EmbeddedWrapper wrapper) {

		assertThat(wrapper.getValue(), is(instanceOf(Collection.class)));
		assertThat((Collection<?>) wrapper.getValue(), is(empty()));
	}
}