SpringBoot Document how to use WebTestClientBuilderCustomizer to configure REST Docs' parameterized output

We already have an example showing how to do it with MockMvc. It'd be good to have an equivalent example for WebTestClient. See https://github.com/spring-projects/spring-restdocs/issues/741 for some background.

Comment From: brneto

I just noticed an issue with this approach with my Spring Contract Testing. I'm investigating why first. I share it with you anyway.

I have a base contract base class that implements an abstract class where the RestAssureWebTestClient happens. e.g.

ContractBase:

abstract class ChassisBase extends ContractTest {

    @MockBean
    private Service service;

    @BeforeEach
    void setUp() {
        // init
        webTestClientSetup();

        // given
        var entity =
                new Entity()
                        .setId(1L)
                        .setName("test name")
                        .setDescription("description test");

        given(service.findAllItems())
                .willReturn(Flux.just(entity));
    }
}

AbstractContractTest (working):

@WebFluxTest
@AutoConfigureRestDocs
abstract class ContractTest {

    @Autowired
    private ApplicationContext context;

    @Autowired
    private WebTestClientRestDocumentationConfigurer configurer;

    void webTestClientSetup() {
        RestAssuredWebTestClient.webTestClient(
                WebTestClient
                        .bindToApplicationContext(context)
                        .configureClient()
                        .filter(configurer)
                        .entityExchangeResultConsumer(document("{class-name}/{method-name}"))
                        .build());
    }

AbstractContractTest (not working):

@WebFluxTest
@AutoConfigureRestDocs
abstract class ContractTest {

    @TestConfiguration
    static class RestDocsParameterizedOutput {

        @Bean
        WebTestClientBuilderCustomizer restDocsParameterizedOutput() {
            return builder -> builder.entityExchangeResultConsumer(document("{class-name}/{method-name}"));
        }
    }

    @Autowired
    private WebTestClient webClient;

    void webTestClientSetup() {
        RestAssuredWebTestClient.webTestClient(webTestClient);
    }

Comment From: wilkinsona

Closing in favor of #27755.