UserControllerClientTests.java

/*
 * 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 example.users;

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

import example.users.UserController.UserPayload;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.data.web.ProjectingJackson2HttpMessageConverter;
import org.springframework.data.web.XmlBeamHttpMessageConverter;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * Integration tests for {@link UserController} to demonstrate client-side resilience of the payload type against
 * changes in the representation.
 * 
 * @author Oliver Gierke
 */
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class UserControllerClientTests {

	@Autowired TestRestTemplate template;

	/**
	 * Custom configuration for the test to enrich the {@link TestRestTemplate} with the {@link HttpMessageConverter}s for
	 * XML and JSON projections.
	 *
	 * @author Oliver Gierke
	 */
	@Configuration
	@Import(Application.class)
	static class Config {

		@Bean
		RestTemplateBuilder builder() {
			return new RestTemplateBuilder()//
					.additionalMessageConverters(new ProjectingJackson2HttpMessageConverter())//
					.additionalMessageConverters(new XmlBeamHttpMessageConverter());
		}
	}

	@Test
	public void accessJsonFieldsOnSimplePayload() {
		assertDave(issueGet("/", MediaType.APPLICATION_JSON));
	}

	@Test
	public void accessJsonFieldsOnNestedPayload() {
		assertDave(issueGet("/changed", MediaType.APPLICATION_JSON));
	}

	@Test
	public void accessXmlElementsOnSimplePayload() {
		assertDave(issueGet("/", MediaType.APPLICATION_XML));
	}

	@Test
	public void accessXmlElementsOnNestedPayload() {
		assertDave(issueGet("/changed", MediaType.APPLICATION_XML));
	}

	private UserPayload issueGet(String path, MediaType mediaType) {

		HttpHeaders headers = new HttpHeaders();
		headers.add(HttpHeaders.ACCEPT, mediaType.toString());

		return template.exchange(path, HttpMethod.GET, new HttpEntity<Void>(headers), UserPayload.class).getBody();
	}

	private static void assertDave(UserPayload payload) {

		assertThat(payload.getFirstname(), is("Dave"));
		assertThat(payload.getLastname(), is("Matthews"));
	}
}