学习如何使用本教程中提供的工具，并在 Spring Boot 环境中编写单元测试和集成测试。
1. 概览
本文中，我们将了解如何编写单元测试并将其集成在 Spring Boot 环境中。你可在网上找到大量关于这个主题的教程，但很难在一个页面中找到你需要的所有信息。我经常注意到初级开发人员混淆了单元测试和集成测试的概念，特别是在谈到 Spring 生态系统时。我将尝试讲清楚不同注解在不同上下文中的用法。
2. 单元测试 vs. 集成测试
维基百科是这么说单元测试的：
在计算机编程中，单元测试是一种软件测试方法，用以测试源代码的单个单元、一个或多个计算机程序模块的集合以及相关的控制数据、使用过程和操作过程，以确定它们是否适合使用。
集成测试：
“集成测试（有时也称集成和测试，缩写为 I&T）是软件测试的一个阶段，在这个阶段中，各个软件模块被组合在一起来进行测试。”
简而言之，当我们在做单元测试时，只是测试了一个代码单元，每次只测试一个方法，不包括与正测试组件相交互的其他所有组件。
另一方面，在集成测试中，我们测试各组件之间的集成。由于单元测试，我们可知这些组件行为与所需一致，但不清楚它们是如何在一起工作的。这就是集成测试的职责。
3. Java 单元测试
所有 Java 开发者都知道 JUnit 是执行单元测试的主要框架。它提供了许多注解来对期望进行断言。
Hamcrest 是一个用于软件测试的附加框架。Hamcrest 允许使用现有的 matcher 类来检查代码中的条件，还允许自定义 matcher 实现。要在 JUnit 中使用 Hamcrest matcher，必须使用 assertThat 语句，后跟一个或多个 matcher。
在这里，你可以看到使用这两种框架的简单测试：
import static org.hamcrest.CoreMatchers.allOf;
import static org.hamcrest.CoreMatchers.anyOf;
import static org.hamcrest.CoreMatchers.both;
import static org.hamcrest.CoreMatchers.containsString;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.everyItem;
import static org.hamcrest.CoreMatchers.hasItems;
import static org.hamcrest.CoreMatchers.not;
import static org.hamcrest.CoreMatchers.sameInstance;
import static org.hamcrest.CoreMatchers.startsWith;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNotSame;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
import java.util.Arrays;
import org.hamcrest.core.CombinableMatcher;
import org.junit.Test;
public class AssertTests {
@Test
public void testAssertArrayEquals() {
byte[] expected = "trial".getBytes();
byte[] actual = "trial".getBytes();
assertArrayEquals("failure - byte arrays not same", expected, actual);
}
@Test
public void testAssertEquals() {
assertEquals("failure - strings are not equal", "text", "text");
}
@Test
public void testAssertFalse() {
assertFalse("failure - should be false", false);
}
@Test
public void testAssertNotNull() {
assertNotNull("should not be null", new Object());
}
@Test
public void testAssertNotSame() {
assertNotSame("should not be same Object", new Object(), new Object());
}
@Test
public void testAssertNull() {
assertNull("should be null", null);
}
@Test
public void testAssertSame() {
Integer aNumber = Integer.valueOf(768);
assertSame("should be same", aNumber, aNumber);
}
// JUnit Matchers assertThat
@Test
public void testAssertThatBothContainsString() {
assertThat("albumen", both(containsString("a")).and(containsString("b")));
}
@Test
public void testAssertThatHasItems() {
assertThat(Arrays.asList("one", "two", "three"), hasItems("one", "three"));
}
@Test
public void testAssertThatEveryItemContainsString() {
assertThat(Arrays.asList(new String[] { "fun", "ban", "net" }), everyItem(containsString("n")));
}
// Core Hamcrest Matchers with assertThat
@Test
public void testAssertThatHamcrestCoreMatchers() {
assertThat("good", allOf(equalTo("good"), startsWith("good")));
assertThat("good", not(allOf(equalTo("bad"), equalTo("good"))));
assertThat("good", anyOf(equalTo("bad"), equalTo("good")));
assertThat(7, not(CombinableMatcher.<Integer> either(equalTo(3)).or(equalTo(4))));
assertThat(new Object(), not(sameInstance(new Object())));
}
@Test
public void testAssertTrue() {
assertTrue("failure - should be true", true);
}
}
4. 介绍我们的案例
让我们来写一个简单的程序吧。其目的是为漫画提供一个基本的搜索引擎。
4.1. Maven 依赖
首先，需要添加一些依赖到我们的工程中。
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.16.20</version> <scope>provided</scope> </dependency>
4.2. 定义 Model
我们的模型非常简单，只有两个类组成：Manga 和 MangaResult
4.2.1. Manga 类
Manga 类表示系统检索到的 Manga 实例。使用 Lombok 来减少样板代码。
package com.mgiglione.model;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
@Getter @Setter @NoArgsConstructor @AllArgsConstructor @Builder
public class Manga {
private String title;
private String description;
private Integer volumes;
private Double score;
}
4.2.2. MangaResult
MangaResult 类是包含了一个 Manga List 的包装类。
package com.mgiglione.model;
import java.util.List;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
@Getter @Setter @NoArgsConstructor
public class MangaResult {
private List<Manga> result;
}
4.3. 实现 Service
为实现本 Service，我们将使用由 Jikan Moe 提供的免费 API 接口。
RestTemplate 是用来对 API 进行发起 REST 调用的 Spring 类。
package com.mgiglione.service;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
import com.mgiglione.model.Manga;
import com.mgiglione.model.MangaResult;
@Service
public class MangaService {
Logger logger = LoggerFactory.getLogger(MangaService.class);
private static final String MANGA_SEARCH_URL="http://api.jikan.moe/search/manga/";
@Autowired
RestTemplate restTemplate;
public List<Manga> getMangasByTitle(String title) {
return restTemplate.getForEntity(MANGA_SEARCH_URL+title, MangaResult.class).getBody().getResult();
}
}
4.4. 实现 Controller
下一步就是写一个暴露了两个端点的 REST Controller，一个是同步的，一个是异步的，其仅用于测试目的。该 Controller 使用了上面定义的 Service。
package com.mgiglione.controller;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Async;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import com.mgiglione.model.Manga;
import com.mgiglione.service.MangaService;
@RestController
@RequestMapping(value = "/manga")
public class MangaController {
Logger logger = LoggerFactory.getLogger(MangaController.class);
@Autowired
private MangaService mangaService;
@RequestMapping(value = "/async/{title}", method = RequestMethod.GET)
@Async
public CompletableFuture<List<Manga>> searchASync(@PathVariable(name = "title") String title) {
return CompletableFuture.completedFuture(mangaService.getMangasByTitle(title));
}
@RequestMapping(value = "/sync/{title}", method = RequestMethod.GET)
public @ResponseBody <List<Manga>> searchSync(@PathVariable(name = "title") String title) {
return mangaService.getMangasByTitle(title);
}
}
4.5. 启动并测试系统
mvn spring-boot:run
然后，Let's try it：
curl http://localhost:8080/manga/async/ken curl http://localhost:8080/manga/sync/ken
示例输出：
{
"title":"Rurouni Kenshin: Meiji Kenkaku Romantan",
"description":"Ten years have passed since the end of Bakumatsu, an era of war that saw the uprising of citizens against the Tokugawa shogunate. The revolutionaries wanted to create a time of peace, and a thriving c...",
"volumes":28,
"score":8.69
},
{
"title":"Sun-Ken Rock",
"description":"The story revolves around Ken, a man from an upper-class family that was orphaned young due to his family's involvement with the Yakuza; he became a high school delinquent known for fighting. The only...",
"volumes":25,
"score":8.12
},
{
"title":"Yumekui Kenbun",
"description":"For those who suffer nightmares, help awaits at the Ginseikan Tea House, where patrons can order much more than just Darjeeling. Hiruko is a special kind of a private investigator. He's a dream eater....",
"volumes":9,
"score":7.97
}
5. Spring Boot 应用的单元测试
Spring Boot 提供了一个强大的类以使测试变得简单： @SpringBootTest 注解
可以在基于 Spring Boot 运行的测试类上指定此注解。
除常规 Spring TestContext Framework 之外，其还提供以下功能：
此处，我们仅有两个组件需要测试：MangaService 和 MangaController
5.1. 对 MangaService 进行单元测试
为了测试 MangaService，我们需要将其与外部组件隔离开来。本例中，只需要一个外部组件：RestTemplate，我们用它来调用远程 API。
我们需要做的是模拟 RestTemplate Bean，并让它始终以固定的给定响应进行响应。Spring Test 结合并扩展了 Mockito 库，通过 @MockBean 注解，我们可以配置模拟 Bean。
package com.mgiglione.service.test.unit;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.when;
import java.io.IOException;
import java.util.List;
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.mock.mockito.MockBean;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.web.client.RestTemplate;
import static org.assertj.core.api.Assertions.assertThat;
import com.mgiglione.model.Manga;
import com.mgiglione.model.MangaResult;
import com.mgiglione.service.MangaService;
import com.mgiglione.utils.JsonUtils;
@RunWith(SpringRunner.class)
@SpringBootTest
public class MangaServiceUnitTest {
@Autowired
private MangaService mangaService;
// MockBean is the annotation provided by Spring that wraps mockito one
// Annotation that can be used to add mocks to a Spring ApplicationContext.
// If any existing single bean of the same type defined in the context will be replaced by the mock, if no existing bean is defined a new one will be added.
@MockBean
private RestTemplate template;
@Test
public void testGetMangasByTitle() throws IOException {
// Parsing mock file
MangaResult mRs = JsonUtils.jsonFile2Object("ken.json", MangaResult.class);
// Mocking remote service
when(template.getForEntity(any(String.class), any(Class.class))).thenReturn(new ResponseEntity(mRs, HttpStatus.OK));
// I search for goku but system will use mocked response containing only ken, so I can check that mock is used.
List<Manga> mangasByTitle = mangaService.getMangasByTitle("goku");
assertThat(mangasByTitle).isNotNull()
.isNotEmpty()
.allMatch(p -> p.getTitle()
.toLowerCase()
.contains("ken"));
}
}
5.2. 对 MangaController 进行单元测试
正如在 MangaService 的单元测试中所做的那样，我们需要隔离组件。在这种情况下，我们需要模拟 MangaService Bean。
然后，我们还有一个问题……Controller 部分是管理 HttpRequest 的系统的一部分，因此我们需要一个系统来模拟这种行为，而非启动完整的 HTTP 服务器。
MockMvc 是执行该操作的 Spring 类。其可以以不同的方式进行设置：
package com.mgiglione.service.test.unit;
import static org.hamcrest.Matchers.is;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.when;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.request;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;
import java.util.ArrayList;
import java.util.List;
import org.junit.Before;
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.mock.mockito.MockBean;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.web.context.WebApplicationContext;
import com.mgiglione.controller.MangaController;
import com.mgiglione.model.Manga;
import com.mgiglione.service.MangaService;
@SpringBootTest
@RunWith(SpringRunner.class)
public class MangaControllerUnitTest {
MockMvc mockMvc;
@Autowired
protected WebApplicationContext wac;
@Autowired
MangaController mangaController;
@MockBean
MangaService mangaService;
/**
* List of samples mangas
*/
private List<Manga> mangas;
@Before
public void setup() throws Exception {
this.mockMvc = standaloneSetup(this.mangaController).build();// Standalone context
// mockMvc = MockMvcBuilders.webAppContextSetup(wac)
// .build();
Manga manga1 = Manga.builder()
.title("Hokuto no ken")
.description("The year is 199X. The Earth has been devastated by nuclear war...")
.build();
Manga manga2 = Manga.builder()
.title("Yumekui Kenbun")
.description("For those who suffer nightmares, help awaits at the Ginseikan Tea House, where patrons can order much more than just Darjeeling. Hiruko is a special kind of a private investigator. He's a dream eater....")
.build();
mangas = new ArrayList<>();
mangas.add(manga1);
mangas.add(manga2);
}
@Test
public void testSearchSync() throws Exception {
// Mocking service
when(mangaService.getMangasByTitle(any(String.class))).thenReturn(mangas);
mockMvc.perform(get("/manga/sync/ken").contentType(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$[0].title", is("Hokuto no ken")))
.andExpect(jsonPath("$[1].title", is("Yumekui Kenbun")));
}
@Test
public void testSearchASync() throws Exception {
// Mocking service
when(mangaService.getMangasByTitle(any(String.class))).thenReturn(mangas);
MvcResult result = mockMvc.perform(get("/manga/async/ken").contentType(MediaType.APPLICATION_JSON))
.andDo(print())
.andExpect(request().asyncStarted())
.andDo(print())
// .andExpect(status().is2xxSuccessful()).andReturn();
.andReturn();
// result.getRequest().getAsyncContext().setTimeout(10000);
mockMvc.perform(asyncDispatch(result))
.andDo(print())
.andExpect(status().isOk())
.andExpect(jsonPath("$[0].title", is("Hokuto no ken")));
}
}
正如在代码中所看到的那样，选择第一种解决方案是因为其是最轻量的一个，并且我们可以对 Spring 上下文中加载的对象有更好的治理。
在异步测试中，必须首先通过调用服务，然后启动 asyncDispatch 方法来模拟异步行为。
6. Spring Boot 应用的集成测试
对于集成测试，我们希望提供下游通信来检查我们的主要组件。
6.1. 对 MangaService 进行集成测试
这个测试也是非常简单的。我们不需要模拟任何东西，因为我们的目的就是要调用远程 Manga API。
package com.mgiglione.service.test.integration;
import static org.assertj.core.api.Assertions.assertThat;
import java.util.List;
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.test.context.junit4.SpringRunner;
import com.mgiglione.model.Manga;
import com.mgiglione.service.MangaService;
@RunWith(SpringRunner.class)
@SpringBootTest
public class MangaServiceIntegrationTest {
@Autowired
private MangaService mangaService;
@Test
public void testGetMangasByTitle() {
List<Manga> mangasByTitle = mangaService.getMangasByTitle("ken");
assertThat(mangasByTitle).isNotNull().isNotEmpty();
}
}
6.2. 对 MangaController 进行集成测试
这个测试和单元测试很是相似，但在这个案例中，我们无需再模拟 MangaService。
package com.mgiglione.service.test.integration;
import static org.hamcrest.Matchers.hasItem;
import static org.hamcrest.Matchers.is;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.request;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;
import org.junit.Before;
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.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.web.context.WebApplicationContext;
import com.mgiglione.controller.MangaController;
@SpringBootTest
@RunWith(SpringRunner.class)
public class MangaControllerIntegrationTest {
// @Autowired
MockMvc mockMvc;
@Autowired
protected WebApplicationContext wac;
@Autowired
MangaController mangaController;
@Before
public void setup() throws Exception {
this.mockMvc = standaloneSetup(this.mangaController).build();// Standalone context
// mockMvc = MockMvcBuilders.webAppContextSetup(wac)
// .build();
}
@Test
public void testSearchSync() throws Exception {
mockMvc.perform(get("/manga/sync/ken").contentType(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$.*.title", hasItem(is("Hokuto no Ken"))));
}
@Test
public void testSearchASync() throws Exception {
MvcResult result = mockMvc.perform(get("/manga/async/ken").contentType(MediaType.APPLICATION_JSON))
.andDo(print())
.andExpect(request().asyncStarted())
.andDo(print())
.andReturn();
mockMvc.perform(asyncDispatch(result))
.andDo(print())
.andExpect(status().isOk())
.andExpect(jsonPath("$.*.title", hasItem(is("Hokuto no Ken"))));
}
}
7. 结论
我们已经了解了在 Spring Boot 环境下单元测试和集成测试的主要不同，了解了像 Hamcrest 这样简化测试编写的框架。当然，也可以在我的 GitHub 仓库 里找到所有代码。
原文：https://dzone.com/articles/unit-and-integration-tests-in-spring-boot-2
作者：Marco Giglione
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持亿速云。
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