LinkUnitTest.java

/*
 * Copyright 2012-2016 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.hateoas;

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

import java.io.IOException;
import java.io.ObjectOutputStream;

import org.apache.commons.io.output.ByteArrayOutputStream;
import org.junit.Test;

/**
 * Unit tests for {@link Link}.
 * 
 * @author Oliver Gierke
 */
public class LinkUnitTest {

	@Test
	public void linkWithHrefOnlyBecomesSelfLink() {
		Link link = new Link("foo");
		assertThat(link.getRel(), is(Link.REL_SELF));
	}

	@Test
	public void createsLinkFromRelAndHref() {
		Link link = new Link("foo", Link.REL_SELF);
		assertThat(link.getHref(), is("foo"));
		assertThat(link.getRel(), is(Link.REL_SELF));
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsNullHref() {
		new Link(null);
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsNullRel() {
		new Link("foo", null);
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsEmptyHref() {
		new Link("");
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsEmptyRel() {
		new Link("foo", "");
	}

	@Test
	public void sameRelAndHrefMakeSameLink() {

		Link left = new Link("foo", Link.REL_SELF);
		Link right = new Link("foo", Link.REL_SELF);

		TestUtils.assertEqualAndSameHashCode(left, right);
	}

	@Test
	public void differentRelMakesDifferentLink() {

		Link left = new Link("foo", Link.REL_PREVIOUS);
		Link right = new Link("foo", Link.REL_NEXT);

		TestUtils.assertNotEqualAndDifferentHashCode(left, right);
	}

	@Test
	public void differentHrefMakesDifferentLink() {

		Link left = new Link("foo", Link.REL_SELF);
		Link right = new Link("bar", Link.REL_SELF);

		TestUtils.assertNotEqualAndDifferentHashCode(left, right);
	}

	@Test
	public void differentTypeDoesNotEqual() {
		assertThat(new Link("foo"), is(not((Object) new ResourceSupport())));
	}

	@Test
	public void returnsNullForNullOrEmptyLink() {

		assertThat(Link.valueOf(null), is(nullValue()));
		assertThat(Link.valueOf(""), is(nullValue()));
	}

	@Test
	public void parsesRFC5988HeaderIntoLink() {

		assertThat(Link.valueOf("</something>;rel=\"foo\""), is(new Link("/something", "foo")));
		assertThat(Link.valueOf("</something>;rel=\"foo\";title=\"Some title\""), is(new Link("/something", "foo")));
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsMissingRelAttribute() {
		Link.valueOf("</something>);title=\"title\"");
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsLinkWithoutAttributesAtAll() {
		Link.valueOf("</something>);title=\"title\"");
	}

	@Test(expected = IllegalArgumentException.class)
	public void rejectsNonRFC5988String() {
		Link.valueOf("foo");
	}

	/**
	 * @see #137
	 */
	@Test
	public void isTemplatedIfSourceContainsTemplateVariables() {

		Link link = new Link("/foo{?page}");

		assertThat(link.isTemplated(), is(true));
		assertThat(link.getVariableNames(), hasSize(1));
		assertThat(link.getVariableNames(), hasItem("page"));
		assertThat(link.expand("2"), is(new Link("/foo?page=2")));
	}

	/**
	 * @see #137
	 */
	@Test
	public void isntTemplatedIfSourceDoesNotContainTemplateVariables() {

		Link link = new Link("/foo");

		assertThat(link.isTemplated(), is(false));
		assertThat(link.getVariableNames(), hasSize(0));
	}

	/**
	 * @see #172
	 */
	@Test
	public void serializesCorrectly() throws IOException {

		Link link = new Link("http://foobar{?foo,bar}");

		ObjectOutputStream stream = new ObjectOutputStream(new ByteArrayOutputStream());
		stream.writeObject(link);
		stream.close();
	}

	/**
	 * @see #312
	 */
	@Test
	public void keepsCompleteBaseUri() {

		Link link = new Link("/customer/{customerId}/programs", "programs");
		assertThat(link.getHref(), is("/customer/{customerId}/programs"));
	}

	/**
	 * @see #504
	 */
	@Test
	public void parsesLinkRelationWithDotAndMinus() {
		assertThat(Link.valueOf("<http://localhost>; rel=\"rel-with-minus-and-.\"").getRel(), is("rel-with-minus-and-."));
	}

	/**
	 * @see #504
	 */
	@Test
	public void parsesUriLinkRelations() {

		assertThat(Link.valueOf("<http://localhost>; rel=\"http://acme.com/rels/foo-bar\"").getRel(),
				is("http://acme.com/rels/foo-bar"));
	}
}