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

我们来测试下前面封装好的 WebClient，这里开始，我们使用 spock 编写 groovy 单元测试，这种编写出来的单元测试，代码更加简洁，同时更加灵活，我们在接下来的单元测试代码中就能看出来。

编写基于 spock 的 spring-boot context 测试

我们加入前面设计的配置，编写测试类：

@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 {
    }
}

我们加入三个服务实例供单元测试调用：

class WebClientUnitTest extends Specification {
    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")))
}

我们要动态的指定负载均衡获取服务实例列表的响应，即去 Mock 负载均衡器的 ServiceInstanceListSupplier 并覆盖：

class WebClientUnitTest extends Specification {

    @Autowired
    private Tracer tracer
    @Autowired
    private ServiceInstanceMetrics serviceInstanceMetrics

    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)
    }
}

之后，我们可以通过下面的 groovy 代码，动态指定微服务返回实例：

//指定 testService 微服务的 LoadBalancer 为 loadBalancerClientFactoryInstance
loadBalancerClientFactory.getInstance("testService") >> loadBalancerClientFactoryInstance
//指定 testService 微服务实例列表为 zone1Instance1, zone1Instance3
serviceInstanceListSupplier.get() >> Flux.just(Lists.newArrayList(zone1Instance1, zone1Instance3))

测试断路器异常重试以及断路器级别

我们需要验证：

• 对于断路器打开的异常，由于没有请求发出去，所以需要直接重试其他的实例。我们可以设立一个微服务，包含两个实例，将其中一个实例的某个路径断路器打开，之后多次调用这个微服务的这个路径接口，看是否都调用成功（由于有重试，所以每次调用都会成功）。同时验证，对于负载均衡器获取服务实例的调用，多于调用次数（每次重试都会调用负载均衡器获取一个新的实例用于调用）
• 某个路径断路器打开的时候，其他路径断路器不会打开。在上面打开一个微服务某个实例的一个路径的断路器之后，我们调用其他的路径，无论多少次，都成功并且调用负载均衡器获取服务实例的次数等于调用次数，代表没有重试，也就是没有断路器异常。

编写代码：

@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 "测试断路器异常重试以及断路器级别"() {
        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: "断路器打开"
            //清除断路器影响
            circuitBreakerRegistry.getAllCircuitBreakers().forEach({ c -> c.reset() })
            loadBalancerClientFactoryInstance = (RoundRobinWithRequestSeparatedPositionLoadBalancer) loadBalancerClientFactory.getInstance("testService")
            def breaker
            try {
                breaker = circuitBreakerRegistry.circuitBreaker("httpbin.org:80/anything", "testService")
            } catch (ConfigurationNotFoundException e) {
                breaker = circuitBreakerRegistry.circuitBreaker("httpbin.org:80/anything")
            }
            //打开实例 3 的断路器
            breaker.transitionToOpenState()
            //调用 10 次
            for (i in 0..<10) {
                Mono<String> stringMono = webClientNamedContextFactory.getWebClient("testService")
                                                                      .get().uri("/anything").retrieve()
                                                                      .bodyToMono(String.class)
                println(stringMono.block())
            }
        then:"调用至少 10 次负载均衡器且没有异常即成功"
            (10.._) * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
        when: "调用不同的路径，验证断路器在这个路径上都是关闭"
            //调用 10 次
            for (i in 0..<10) {
                Mono<String> stringMono = webClientNamedContextFactory.getWebClient("testService")
                                                                      .get().uri("/status/200").retrieve()
                                                                      .bodyToMono(String.class)
                println(stringMono.block())
            }
        then: "调用必须为正好 10 次代表没有重试，一次成功，断路器之间相互隔离"
            10 * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
    }
}

测试针对 connectTimeout 重试

对于连接超时，我们需要验证：无论是否可以重试的方法或者路径，都必须重试，因为请求并没有真的发出去。可以这样验证：设置微服务 testServiceWithCannotConnect 一个实例正常，另一个实例会连接超时，我们配置了重试 3 次，所以每次请求应该都能成功，并且随着程序运行，后面的调用不可用的实例还会被断路，照样可以成功调用。

@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 connectTimeout 重试"() {
        given: "设置微服务 testServiceWithCannotConnect 一个实例正常，另一个实例会连接超时"
            loadBalancerClientFactory.getInstance("testServiceWithCannotConnect") >> loadBalancerClientFactoryInstance
            serviceInstanceListSupplier.get() >> Flux.just(Lists.newArrayList(zone1Instance1, zone1Instance2))
        when:
            //由于我们针对 testService 返回了两个实例，一个可以正常连接，一个不可以，但是我们配置了重试 3 次，所以每次请求应该都能成功，并且随着程序运行，后面的调用不可用的实例还会被断路
            //这里主要测试针对 connect time out 还有 断路器打开的情况都会重试，并且无论是 GET 方法还是其他的
            Span span = tracer.nextSpan()
            for (i in 0..<10) {
                Tracer.SpanInScope cleared = tracer.withSpanInScope(span)
                try {
                    //测试 get 方法（默认 get 方法会重试）
                    Mono<String> stringMono = webClientNamedContextFactory.getWebClient("testServiceWithCannotConnect")
                                                                          .get().uri("/anything").retrieve()
                                                                          .bodyToMono(String.class)
                    println(stringMono.block())
                    //测试 post 方法（默认 post 方法针对请求已经发出的不会重试，这里没有发出请求所以还是会重试的）
                    stringMono = webClientNamedContextFactory.getWebClient("testServiceWithCannotConnect")
                                                             .post().uri("/anything").retrieve()
                                                             .bodyToMono(String.class)
                    println(stringMono.block())
                }
                finally {
                    cleared.close()
                }
            }
        then:"调用至少 20 次负载均衡器且没有异常即成功"
            (20.._) * loadBalancerClientFactoryInstance.getInstanceResponseByRoundRobin(*_)
    }
}

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