本系列代码地址：https://github.com/JoJoTec/spring-cloud-parent

我们继续上一节，继续使用 spock 测试我们自己封装的 WebClient

针对响应超时，我们需要验证重试仅针对可以重试的方法（包括 GET 方法以及配置的可重试方法），针对不可重试的方法没有重试。我们可以通过 spock 单元测试中，检查对于负载均衡器获取实例方法的调用次数看出来是否有重试

我们通过 httpbin.org 的 '/delay/秒' 实现 readTimeout，分别验证：

• 测试 GET 延迟 2 秒返回，超过读取超时，这时候会重试
• 测试 POST 延迟 3 秒返回，超过读取超时，同时路径在重试路径中，这样也是会重试的
• 测试 POST 延迟 2 秒返回，超过读取超时，同时路径在重试路径中，这样不会重试

代码如下：

@SpringBootTest(
        properties = [
                "webclient.configs.testServiceWithCannotConnect.baseUrl=http://testServiceWithCannotConnect",
                "webclient.configs.testServiceWithCannotConnect.serviceName=testServiceWithCannotConnect",
                "webclient.configs.testService.baseUrl=http://testService",
                "webclient.configs.testService.serviceName=testService",
                "webclient.configs.testService.responseTimeout=1s",
                "webclient.configs.testService.retryablePaths[0]=/delay/3",
                "webclient.configs.testService.retryablePaths[1]=/status/4*",
                "spring.cloud.loadbalancer.zone=zone1",
                "resilience4j.retry.configs.default.maxAttempts=3",
                "resilience4j.circuitbreaker.configs.default.failureRateThreshold=50",
                "resilience4j.circuitbreaker.configs.default.slidingWindowType=TIME_BASED",
                "resilience4j.circuitbreaker.configs.default.slidingWindowSize=5",
                //因为重试是 3 次，为了防止断路器打开影响测试，设置为正好比重试多一次的次数，防止触发
                //同时我们在测试的时候也需要手动清空断路器统计
                "resilience4j.circuitbreaker.configs.default.minimumNumberOfCalls=4",
                "resilience4j.circuitbreaker.configs.default.recordExceptions=java.lang.Exception"
        ],
        classes = MockConfig
)
class WebClientUnitTest extends Specification {
    @SpringBootApplication
    static class MockConfig {
    }
    @SpringBean
    private LoadBalancerClientFactory loadBalancerClientFactory = Mock()

    @Autowired
    private CircuitBreakerRegistry circuitBreakerRegistry
    @Autowired
    private Tracer tracer
    @Autowired
    private ServiceInstanceMetrics serviceInstanceMetrics
    @Autowired
    private WebClientNamedContextFactory webClientNamedContextFactory

    //不同的测试方法的类对象不是同一个对象，会重新生成，保证互相没有影响
    def zone1Instance1 = new DefaultServiceInstance(instanceId: "instance1", host: "www.httpbin.org", port: 80, metadata: Map.ofEntries(Map.entry("zone", "zone1")))
    def zone1Instance2 = new DefaultServiceInstance(instanceId: "instance2", host: "www.httpbin.org", port: 8081, metadata: Map.ofEntries(Map.entry("zone", "zone1")))
    def zone1Instance3 = new DefaultServiceInstance(instanceId: "instance3", host: "httpbin.org", port: 80, metadata: Map.ofEntries(Map.entry("zone", "zone1")))
    RoundRobinWithRequestSeparatedPositionLoadBalancer loadBalancerClientFactoryInstance = Spy();
    ServiceInstanceListSupplier serviceInstanceListSupplier = Spy();

    //所有测试的方法执行前会调用的方法
    def setup() {
        //初始化 loadBalancerClientFactoryInstance 负载均衡器
        loadBalancerClientFactoryInstance.setTracer(tracer)
        loadBalancerClientFactoryInstance.setServiceInstanceMetrics(serviceInstanceMetrics)
        loadBalancerClientFactoryInstance.setServiceInstanceListSupplier(serviceInstanceListSupplier)
    }

    def "测试针对 readTimeout 重试"() {
        given: "设置 testService 的实例都是正常实例"
            loadBalancerClientFactory.getInstance("testService") >> loadBalancerClientFactoryInstance
            serviceInstanceListSupplier.get() >> Flux.just(Lists.newArrayList(zone1Instance1, zone1Instance3))
        when: "测试 GET 延迟 2 秒返回，超过读取超时"
            //清除断路器影响
            circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
            try {
                webClientNamedContextFactory.getWebClient("testService")
                                            .get().uri("/delay/2").retrieve()
                                            .bodyToMono(String.class).block();
            } catch (WebClientRequestException e) {
                if (e.getCause() in  ReadTimeoutException) {
                    //读取超时忽略
                } else {
                    throw e;
                }
            }
        then: "每次都会超时所以会重试，根据配置一共有 3 次"
            3 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
        when: "测试 POST 延迟 3 秒返回，超过读取超时，同时路径在重试路径中"
            //清除断路器影响
            circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
            try {
                webClientNamedContextFactory.getWebClient("testService")
                                            .post().uri("/delay/3").retrieve()
                                            .bodyToMono(String.class).block();
            } catch (WebClientRequestException e) {
                if (e.getCause() in  ReadTimeoutException) {
                    //读取超时忽略
                } else {
                    throw e;
                }
            }
        then: "每次都会超时所以会重试，根据配置一共有 3 次"
            3 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
        when: "测试 POST 延迟 2 秒返回，超过读取超时，这个不能重试"
            //清除断路器影响
            circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
            try {
                webClientNamedContextFactory.getWebClient("testService")
                                            .post().uri("/delay/2").retrieve()
                                            .bodyToMono(String.class).block();
            } catch (WebClientRequestException e) {
                if (e.getCause() in  ReadTimeoutException) {
                    //读取超时忽略
                } else {
                    throw e;
                }
            }
        then: "没有重试，只有一次调用"
            1 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
    }
}

对于非 2xx 的响应码，代表请求失败，我们需要测试：

• 测试 GET 返回 500，会有重试

• 测试 POST 返回 500，没有重试

• 测试 POST 返回 400，这个请求路径在重试路径中，会有重试

  @SpringBootTest(
  properties = [
  "webclient.configs.testServiceWithCannotConnect.baseUrl=http://testServiceWithCannotConnect",
  "webclient.configs.testServiceWithCannotConnect.serviceName=testServiceWithCannotConnect",
  "webclient.configs.testService.baseUrl=http://testService",
  "webclient.configs.testService.serviceName=testService",
  "webclient.configs.testService.responseTimeout=1s",
  "webclient.configs.testService.retryablePaths[0]=/delay/3",
  "webclient.configs.testService.retryablePaths[1]=/status/4*",
  "spring.cloud.loadbalancer.zone=zone1",
  "resilience4j.retry.configs.default.maxAttempts=3",
  "resilience4j.circuitbreaker.configs.default.failureRateThreshold=50",
  "resilience4j.circuitbreaker.configs.default.slidingWindowType=TIME_BASED",
  "resilience4j.circuitbreaker.configs.default.slidingWindowSize=5",
  //因为重试是 3 次，为了防止断路器打开影响测试，设置为正好比重试多一次的次数，防止触发
  //同时我们在测试的时候也需要手动清空断路器统计
  "resilience4j.circuitbreaker.configs.default.minimumNumberOfCalls=4",
  "resilience4j.circuitbreaker.configs.default.recordExceptions=java.lang.Exception"
  ],
  classes = MockConfig
  )
  class WebClientUnitTest extends Specification {
  @SpringBootApplication
  static class MockConfig {
  }
  @SpringBean
  private LoadBalancerClientFactory loadBalancerClientFactory = Mock()

  @Autowired
  private CircuitBreakerRegistry circuitBreakerRegistry
  @Autowired
  private Tracer tracer
  @Autowired
  private ServiceInstanceMetrics serviceInstanceMetrics
  @Autowired
  private WebClientNamedContextFactory webClientNamedContextFactory
  
  //不同的测试方法的类对象不是同一个对象，会重新生成，保证互相没有影响
  def zone1Instance1 = new DefaultServiceInstance(instanceId: "instance1", host: "www.httpbin.org", port: 80, metadata: Map.ofEntries(Map.entry("zone", "zone1")))
  def zone1Instance2 = new DefaultServiceInstance(instanceId: "instance2", host: "www.httpbin.org", port: 8081, metadata: Map.ofEntries(Map.entry("zone", "zone1")))
  def zone1Instance3 = new DefaultServiceInstance(instanceId: "instance3", host: "httpbin.org", port: 80, metadata: Map.ofEntries(Map.entry("zone", "zone1")))
  RoundRobinWithRequestSeparatedPositionLoadBalancer loadBalancerClientFactoryInstance = Spy();
  ServiceInstanceListSupplier serviceInstanceListSupplier = Spy();
  
  //所有测试的方法执行前会调用的方法
  def setup() {
      //初始化 loadBalancerClientFactoryInstance 负载均衡器
      loadBalancerClientFactoryInstance.setTracer(tracer)
      loadBalancerClientFactoryInstance.setServiceInstanceMetrics(serviceInstanceMetrics)
      loadBalancerClientFactoryInstance.setServiceInstanceListSupplier(serviceInstanceListSupplier)
  }
  
  def "测试非 200 响应码返回" () {
      given: "设置 testService 的实例都是正常实例"
          loadBalancerClientFactory.getInstance("testService") >> loadBalancerClientFactoryInstance
          serviceInstanceListSupplier.get() >> Flux.just(Lists.newArrayList(zone1Instance1, zone1Instance3))
      when: "测试 GET 返回 500"
          //清除断路器影响
          circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
          try {
              webClientNamedContextFactory.getWebClient("testService")
                                          .get().uri("/status/500").retrieve()
                                          .bodyToMono(String.class).block();
          } catch (WebClientResponseException e) {
              if (e.getStatusCode().is5xxServerError()) {
                  //5xx忽略
              } else {
                  throw e;
              }
          }
      then: "每次都没有返回 2xx 所以会重试，根据配置一共有 3 次"
          3 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
      when: "测试 POST 返回 500"
          //清除断路器影响
          circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
          try {
              webClientNamedContextFactory.getWebClient("testService")
                                          .post().uri("/status/500").retrieve()
                                          .bodyToMono(String.class).block();
          } catch (WebClientResponseException e) {
              if (e.getStatusCode().is5xxServerError()) {
                  //5xx忽略
              } else {
                  throw e;
              }
          }
      then: "POST 默认不重试，所以只会调用一次"
          1 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
      when: "测试 POST 返回 400，这个请求路径在重试路径中"
          //清除断路器影响
          circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
          try {
              webClientNamedContextFactory.getWebClient("testService")
                                          .post().uri("/status/400").retrieve()
                                          .bodyToMono(String.class).block();
          } catch (WebClientResponseException e) {
              if (e.getStatusCode().is4xxClientError()) {
                  //4xx忽略
              } else {
                  throw e;
              }
          }
      then: "路径在重试路径中，所以会重试"
          3 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
  }

  }

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