java - WebTestClient 变异过滤器 java.lang.IllegalStateException : No "WebTestClient-Request-Id" header

Question

我正在尝试使用 WebTestClient 为 ExchangeFilterFunctions 编写单元测试，但是在更改并向 webTestClient 添加过滤器时遇到此错误。

java.lang.IllegalStateException: No "WebTestClient-Request-Id" header

    at org.springframework.util.Assert.state(Assert.java:94)
    at org.springframework.test.web.reactive.server.WiretapConnector.lambda$connect$2(WiretapConnector.java:80)
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:100)
    at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1510)
    at reactor.core.publisher.MonoProcessor.subscribe(MonoProcessor.java:457)
    at reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55)
    at reactor.core.publisher.MonoPeek.subscribe(MonoPeek.java:71)
    at reactor.core.publisher.MonoPeek.subscribe(MonoPeek.java:71)
    at reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55)
    at reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
    at reactor.core.publisher.Mono.block(Mono.java:1517)
    at org.springframework.test.web.reactive.server.DefaultWebTestClient$DefaultRequestBodyUriSpec.exchange(DefaultWebTestClient.java:283)
    at com.ecs.springframework.reactive.web.filter.EcsMdcRequestExchangeFilterTest.whenExchangeFilterFunctionInjectedIntoWebTestClient_thenWebTestClientShouldIncludeHeader

添加以下测试中的注释行并导致上述错误:

  @Test
  void whenExchangeFilterFunctionInjectedIntoWebTestClient_thenWebTestClientShouldIncludeHeader() {

    RouterFunction function =
        RouterFunctions.route(
            RequestPredicates.GET("/filter"), request -> ServerResponse.ok().build());

    WebTestClient.bindToRouterFunction(function)
        .build()
    //  .mutate()
    //  .filter(new AddHeaderExchangeFilter())
    //  .build()
        .get()
        .uri("/filter")
        .exchange()
        .expectStatus()
        .isOk()
        .expectHeader()
        .valueMatches("FILTER-HEADER-KEY", "FILTER-HEADER-VALUE");
  }

添加标题交换过滤器

public class AddHeaderExchangeFilter implements ExchangeFilterFunction {

  @Override
  public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {

    ClientRequest newRequest = ClientRequest
            .create(request.method(), request.url())
            .header("FILTER-HEADER-KEY", "FILTER-HEADER-VALUE")
            .build();

    return next.exchange(newRequest);
  }

}

Answer 1

在您的 AddHeaderExchangeFilter 上，您需要添加当前的请求 header

public class AddHeaderExchangeFilter implements ExchangeFilterFunction {

        @Override
        public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {

            ClientRequest newRequest = ClientRequest.create(request.method(), request.url())
                                                    .headers(httpHeaders -> httpHeaders.addAll(request.headers()))
                                                    .header("FILTER-HEADER-KEY", "FILTER-HEADER-VALUE")
                                                    .build();
            return next.exchange(newRequest);
        }
    }

这对于 WebTestClient 正确行为及其在执行 exchange() 时验证它是必要的。
在您的过滤器中，您正在创建一个新请求，并且初始请求中的 header 将被忽略，并且不会传递给 newRequest。

<小时/>

旁注:我猜您尝试测试过滤器是否正常工作，但您当前的测试不是验证请求的 header ，而是验证响应的 header (因此您的测试将失败).
我给您的建议是更改路由器以从请求返回 header

RouterFunction function =
                RouterFunctions.route(
                        RequestPredicates.GET("/filter"), request ->
                            ServerResponse.ok().headers(httpHeaders -> httpHeaders.addAll(request.headers().asHttpHeaders())).build()
                        );