问题

我想使用JUnit 5来适当地对Spring Cloud Gateway的customRouteLocator(RouteLocatorBuilder routeLocatorBuilder)方法进行单元测试。

然而，我在弄清楚要测试什么、断言什么、模拟什么、如何提高覆盖率等方面遇到了困难...
如果可能的话，我只想对这个进行单元测试，不需要启动整个SpringTest等。

@Bean
@Override
public RouteLocator customRouteLocator(RouteLocatorBuilder routeLocatorBuilder) {
    return routeLocatorBuilder.routes()
            .route("forward_to_service_one", r -> r.path("/serviceone/**").and().uri("http://the-first-service:8080"))
            .route("forward_to_service_two", r -> r.path("/servicetwo/**").and().uri("http://the-second-service:8080"))
            .route("forward_to_service_three", r -> r.alwaysTrue().and().order(Ordered.LOWEST_PRECEDENCE).uri("http://the-default-third-service:8080"))
            .build();
}

在使用集成测试时，访问在端点上启动的网关服务，查看请求转发到各自的服务，我想知道是否有一种良好的实践方法来测试这个Spring Cloud Gateway功能。

请提供一些完全覆盖测试用例的示例好吗？

谢谢

<details>
<summary>英文:</summary>

I would like to properly unit test the Spring Cloud Gateway RouteLocator customRouteLocator(RouteLocatorBuilder routeLocatorBuilder) { method with JUnit5.

However, I am having a hard time figuring out what to test, what to assert, what to mock, how to improve coverage, etc...
If possible, I just want to unit test this, no need to start an entire SpringTest etc.

@Bean
@Override
public RouteLocator customRouteLocator(RouteLocatorBuilder routeLocatorBuilder) {
return routeLocatorBuilder.routes()
.route("forward_to_service_one", r -> r.path("/serviceone/").and().uri("http://the-first-service:8080"))
.route("forward_to_service_two", r -> r.path("/servicetwo/").and().uri("http://the-second-service:8080"))
.route("forward_to_service_three", r -> r.alwaysTrue().and().order(Ordered.LOWEST_PRECEDENCE).uri("http://the-default-third-service:8080"))
.build();
}

While working with integration tests, hit the gateway service that is started on the endpoint, seeing the requests forwarded to respective services, I was wondering if there is a good practice to test this Spring Cloud Gateway feature.

Any example of fully covered test cases please?

Thank you

</details>


# 答案1
**得分**: 2

以下是翻译好的内容：

我无法理解您的测试场景（您想要测试什么，如果服务是否正确配置了路径等）。但我想向您展示两种方法，第一种是基本方法，第二种是更复杂的方法，如果您需要更多的控制。

## 简单方法

这将是直接的。我在我的SpringBootTest属性中添加了一些路由，我使用了Spring提供给我用于针对Netty进行响应式测试的WebTestClient实用程序。然后在我的测试中，我只是发送请求到这个 **/test** 端点，并期望它被配置好（根据您的实现，如果您没有扩展Spring Cloud Gateway，我可以说这个测试是无用的，我们不应该测试Spring Cloud Gateway的功能，但无论如何这是我从您的描述中理解的）

```java
@RunWith(SpringRunner.class)
@SpringBootTest(properties = {
    "spring.cloud.gateway.routes[0].id=test",
    "spring.cloud.gateway.routes[0].uri=http://localhost:8081",
    "spring.cloud.gateway.routes[0].predicates[0]=Path=/test/**",
}, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class NettyRoutingFilterTests {

    @Autowired
    private ApplicationContext context;

    @Test
    @Ignore
    public void mockServerWorks() {
        WebTestClient client = WebTestClient.bindToApplicationContext(this.context)
            .build();
        client.get().uri("/test").exchange().expectStatus().isOk();
    }
}

复杂方法

第二种方法是：从您的源代码中设置模拟路由定位器到上下文中，并调用您的服务，断言您的响应。这与从SpringBootProperties设置路由不同，当您出于某种原因需要一些控制时（在我的情况下，我们正在使用契约测试，我不会详细介绍），但是这里是我没有完全尝试的一些模拟示例（但在我的项目中使用相同的方法），但它应该给您一个想法和一个起点。

@ExtendWith( { SpringExtension.class } )
@SpringBootTest(classes = { MockConfigurer.class },
    webEnvironment = WebEnvironment.RANDOM_PORT )
public class RoutingIT
{

    @LocalServerPort
    private int port;

    // 其他部分省略
}

@Configuration
public class MockConfigurer
{
    private List<ServiceInstance> services;

    public MockConfigurer( List<ServiceInstance> services)
    {
        this.services= services;
    }

    @Bean
    public DiscoveryClient discoveryClient( )
    {
        final DiscoveryClient mock = mock( DiscoveryClient.class );
        final Map<String, List<ServiceInstance>> clusters =
            this.services.stream( ).collect( Collectors.groupingBy( ServiceInstance::getServiceId ) );
        given( mock.getServices( ) ).willReturn( new ArrayList<>( clusters.keySet( ) ) );
        clusters.forEach( ( clusterId, services ) -> given( mock.getInstances( clusterId ) ).willReturn( services ) );
        return mock;
    }
}

// 其他部分省略

public class MockService implements ServiceInstance
{
    // fields, constructors

    @Override
    public String getServiceId( )
    {
        return id;
    }

    @Override
    public int getPort( )
    {
        return port;
    }

    // and other functions as well, but you will get the point
}

// 其他部分省略

@RunWith(SpringRunner.class)
@SpringBootTest(properties = {
"spring.cloud.gateway.routes[0].id=test",
"spring.cloud.gateway.routes[0].uri=http://localhost:8081",
"spring.cloud.gateway.routes[0].predicates[0]=Path=/test/**",
}, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class NettyRoutingFilterTests {
@Autowired
private ApplicationContext context;
@Test
@Ignore
public void mockServerWorks() {
WebTestClient client = WebTestClient.bindToApplicationContext(this.context)
.build();
client.get().uri("/test").exchange().expectStatus().isOk();
}

@ExtendWith( { SpringExtension.class } )
@SpringBootTest(classes = { MockConfigurer.class },
webEnvironment = WebEnvironment.RANDOM_PORT )
public class RoutingIT
{
@LocalServerPort
private int port;

@Configuration
public class MockConfigurer
{
private List<ServiceInstance> services;
public MockConfigurer( List<ServiceInstance> services)
{
this.services= services;
}
@Bean
public DiscoveryClient discoveryClient( )
{
final DiscoveryClient mock = mock( DiscoveryClient.class );
final Map<String, List<ServiceInstance>> clusters =
this.services.stream( ).collect( Collectors.groupingBy( ServiceInstance::getServiceId ) );
given( mock.getServices( ) ).willReturn( new ArrayList<>( clusters.keySet( ) ) );
clusters.forEach( ( clusterId, services ) -> given( mock.getInstances( clusterId ) ).willReturn( services ) );
return mock;
}
}

public class MockService implements ServiceInstance
{
// fields, constructors
@Override
public String getServiceId( )
{
return id;
}
@Override
public int getPort( )
{
return port;
}
// and other functions as well, but you will get the point

@Bean
public static MockService mockClusterInstance1( )
{
return new MockService("test", 8081, // more fields based on your implementation, also pay attention this is what we defined in the @SpringBootTest annotation);
}

@Test
public void should_GetResponseFromTest_WhenCalled( ) throws Exception
{
URI uri= new URI( "http://localhost:" + this.port+ "/test");
ResponseEntity<String> res = this.restTemplate.getForEntity( uri, String.class );
assertThat( res.getStatusCodeValue( ) ).isEqualTo( HttpURLConnection.HTTP_OK );
assertThat( res.getBody( ) ).isEqualTo( // your expectation );